IBM Version 7 Release 3. Easy Tier Server SC

Transcription

1 IBM Version 7 Release 3 Easy Tier Server SC

2 This edition applies to Version 7, Release 3 of the IBM Easy Tier Server and to all subsequent releases and modifications until otherwise indicated in new editions. Copyright IBM Corporation US Government Users Restricted Rights Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.

3 Contents Summary of changes v Chapter 1. Easy Tier Server Chapter 2. Easy Tier Server hardware and software requirements Chapter 3. Installing, upgrading, and verifying the Easy Tier Server client software Installing or upgrading the Easy Tier Server client software Verifying the Easy Tier Server client software installation Chapter 4. Configuring, verifying, and unconfiguring the Easy Tier Server client Configuring the Easy Tier Server client software.. 7 Verifying the Easy Tier Server client software configuration Unconfiguring the Easy Tier Server client software. 8 Manually unconfiguring Easy Tier Server client software Verifying the Easy Tier Server client software unconfiguration Chapter 5. Easy Tier Server operations 11 Using the Storage Tier Advisory Tool to monitor Easy Tier Server efficiency Chapter 6. etcadmin command etcadmin -a create command etcadmin -a add command etcadmin -a destroy command etcadmin -a start command etcadmin -a stop command etcadmin -a stopall command etcadmin -a query command etcadmin -a list command etcadmin -a iostat command etcadmin -a shutdown command etcadmin -a cfgetcdd command Chapter 7. Easy Tier Server error-log descriptions Notices Trademarks Copyright IBM Corp iii

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5 Summary of changes Changes to the IBM Easy Tier Server documentation are summarized in this section. Changes include technical changes or additions to the text and illustrations, which are indicated by vertical lines to the left of the changes, as well as terminology, maintenance, and editorial changes. Changed information for Version 7, Release 3 The following information is added to Easy Tier Server hardware and software requirements: v Easy Tier Server is compatible with any AIX configurations, including active-active and active-passive configurations. However, it is not currently compatible with PowerHA HyperSwap. v Updated the command names in the install or upgrade the Easy Tier Server client software on an AIX system. For information, see Installing or upgrading the Easy Tier Server client software on page 5. v Updated the terminology for solid state drive (SSD): flash drive replaced SSD throughout the documentation. Copyright IBM Corp v

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7 Chapter 1. Easy Tier Server Easy Tier Server, an enhancement to the Easy Tier family, is a unified storage caching and tiering solution. The Easy Tier Server utility enables the caching of storage-system data in multiple hosts. It provides cooperative caching that is based on statistics gathered in both the host and storage system. Easy Tier Server copies the most frequently accessed, or hottest, data to direct-attached storage (DAS) flash drive (also known as solid-state drives or SSDs) within Easy Tier Server-enabled hosts. Easy Tier Server caching coherency algorithms ensure that the most valuable data is available on the host local flash-drive devices and guarantees data integrity across DS8870 internal tiers and hosts DAS cache. Data can be read directly from flash memory attached to the host cache rather than from disk drives in the DS8870 storage system. This data-retrieval optimization results in improved performance, with I/O requests that are generally satisfied in microseconds. The Easy Tier Server implementation consists of two major components: v The Easy Tier Server coherency server, which runs on the DS8870 system. The Easy Tier Server coherency server manages how data is placed on the SAN storage tiers and the SAN caches. The coherency server asynchronously communicates with the host system (the coherency client) and generates caching advice for each coherency client, based on Easy Tier placement and statistics. v The Easy Tier Server coherency client, which runs on the host system. The Easy Tier Server coherency client maintains local caches on DAS flash-drive. The coherency client works independently to cache the I/O streams of its applications, providing a real-time performance enhancement. The coherency client uses the Easy Tier Server protocol to establish system-aware caching that interfaces with the coherency server. Figure 1 on page 2 shows a DS8870, which runs the Easy Tier Server coherency server, in conjunction with three host systems, which function as the Easy Tier Server coherency clients. Copyright IBM Corp

8 Figure 1. Basic Easy Tier Server architecture The Easy Tier Server coherency server and the Easy Tier Server coherency client work together as follows: v The coherency client issues SCSI commands to a logical volume to asynchronously communicate with the coherency server. v The coherency server generates frequency-based advice based on a unified view of the SAN storage, hosts, and their access patterns. v The coherency client determines what to cache, what to keep in cache, and what to evict, based on access patterns, coherency server-generated advice, and local statistics (recency- and frequency-based statistics). v The coherency client combines the coherency server advice with its own population list, resulting in both short- and longer-term cache population, higher hit ratio, and better storage solution optimization, including application-aware storage. SAN-based multi-host applications are enabled through the Easy Tier Server SAN storage coherency protocol. With managed coherency, advanced storage-replication functions such as FlashCopy and remote mirroring are transparently enabled. 2 Easy Tier Server

9 Chapter 2. Easy Tier Server hardware and software requirements You must install and configure the following hardware and software components to ensure that the Easy Tier Server coherency client operates successfully. Preliminary requirements Prior to installing the required hardware and software, verify that the following elements are available on your system: v The DS8870 storage firmware level on your storage subsystem supports the Easy Tier Server function. v The Easy Tier Server LIC feature is installed and enabled on your storage subsystem. v Easy Tier Server coherency client software Note: CD/DVD media, which contains the Easy Tier Server coherency client software - bos.etcachedd.rte install package, is available. v For each AIX coherency client, add at least two volumes for each of the DS8000 central processor complex (CPC) enclosures (assuming that you have two extent pools, and each extent pool has been allocated on a separate CPC). Important: Ensure that you have at least two volumes on each storage controller. You can use either the graphical user interface (GUI) or the command-line interface (CLI) to add the volumes. To add volumes using the GUI, select Create Volumes > Select Extent Pools. Proceed with either of the following actions and, when prompted, select Create. - Select both extent pools, and select Spread volumes to balance space equally in pools. - Select the extent pools one at a time, and then create at least two volumes in each extent pool. Perform this action for at least one extent pool on each CPC. To create volumes from the CLI, all volumes must be in the same extent pool. Therefore, you must create at least two volumes in at least two extent pools. Each extent pool must also be on a separate CPC. In the CLI interactive mode, type the following commands. For the variables, provide the values that apply to your system. - mkfbvol -dev storage_image_id -extpool extentpool_id_1 -cap capacity -name volume_name volume_id - mkfbvol -dev storage_image_id -extpool extentpool_id_2 -cap capacity -name volume_name volume_id v For each CPC, enable caching for at least two volumes. v For a SAN adapter in an AIX6.1x host, ensure that the fc_err_recov attribute is configured to fast_fail and the dyntrk attribute is configured to yes. Easy Tier Server coherency server Table 1 lists the requirements and environments for the Easy Tier Server coherency server. Table 1. Easy Tier Server coherency server requirements and environments Requirement Environment DS8000 model/code DS8870 Release 7.1 DS8000 drive types All types supported, with or without multiple tiers Copyright IBM Corp

10 Table 1. Easy Tier Server coherency server requirements and environments (continued) Requirement Environment DS8000 configuration All (1-4 frame, all cache sizes, and so on) Volume types Open volumes only (no count key data [CKD]) Easy Tier Server coherency client Table 2 lists the requirements and environments for the Easy Tier coherency client. Table 2. Easy Tier Server coherency client requirements and environments Requirement Environment Host type System p / AIX Host environment Native AIX Number of hosts running a caching driver attached to a single DS8870 system Maximum Flash-based device size/maximum number of cache devices Notes: v v A Flash-based device is a device that becomes part of the cache when the device is added to the cache. Refer to your operating system instructions for information about creating Flash-based devices. Maximum of 16 per DS8870 central processor complex (CPC) Maximum values that the host/hardware can support Easy Tier Server coherency client platform requirements and environment Table 3 lists the requirements and environments for the Easy Tier Server coherency client platform. Table 3. Easy Tier Server coherency client platform requirements and environment Requirement Environment Operating system (OS) configuration Native AIX (no Virtual I/O Server [VIOS]) OS levels AIX 6.1 TL8 or AIX 7.1 TL2 Multipath control module Native AIX path control module (AIXPCM), Subsystem Device Driver (SDD) path control module (SDDPCM) Servers Power E4B/E4C/E4D, Power E6B/E6C/E6D, Power E8B, Power E8D, Power RMD, Power MMB/MMC/MMD, Power MHB/MHC/MHD, Power FHB Flash devices Either EXP30 Ultra flash drive I/O Drawer (FC-EDR1) with GX++ 2-port PCIe2 x8 Adapters (FC-1914) Or EXP24S SFF Gen2-bay Drawer (FC-5887) with PCIe2 1.8 GB Cache RAID SAS Adapters Tri-port (FC-5913) FC 5802/5877 Expansion Drawer, flash drive in expansion drawer via RAID SAS adapter SAN hardware All supported switches and Host Bus Adapters (HBAs) that function with the listed storage/servers Note: Easy Tier Server is compatible with any AIX configurations, including active-active and active-passive configurations. However, it is not currently compatible with PowerHA HyperSwap. 4 Easy Tier Server

11 Chapter 3. Installing, upgrading, and verifying the Easy Tier Server client software Follow these procedures to install, upgrade, and verify the Easy Tier Server client software on an AIX system. You must meet the following requirements before Easy Tier Server caching can be used on an IBM DS8870 fixed block logical volume: v The Easy Tier Server licensed feature must be enabled. v The -etccmode parameter on the DS CLI showsi command must be set to enabled. Issue the chsi command to change the parameter value if it is not set correctly. v Set the parameters on the DS CLI chsi command to -etmonitor automode and -etautomode tiered to support only volumes in hybrid pools. Set the parameters to -etmonitor automode and -etautomode all to support all volumes on the DS8870 system. Or, you can set the parameters to -etmonitor all to support all volumes. Issue the chsi command to change a parameter value that is not set correctly. Installing or upgrading the Easy Tier Server client software Follow the procedures in this section to install or upgrade the Easy Tier Server client software on an AIX system. You must meet the following prerequisites before you install the Easy Tier Server client software: v You must log on as root. v To support Easy Tier Server on an AIX cache client system, a supported Flash-based device or devices must be configured on an Easy Tier Server client system. v Verify that the fc_err_recov attribute of the Fibre Channel adapter (which is connected to the SAN storage devices that support the read cache function) is set to fast_fail. The delay_fail setting can cause the read cache function to fail if errors occur in the SAN. v If you are migrating or upgrading Easy Tier Server client software, stop (disable) all read cache enabled SAN devices and remove the Easy Tier Server client etcdd device from the client system before you install the new client software. See the following note for information about automatically saving and restoring the Easy Tier Server configuration during etcdd device un-configuration or client software migration. Notes: A SAN device is read cache enabled after the administrator issues the etcadmin -a start command to enable Easy Tier Server caching on the device. To save and automatically restore the current Easy Tier Server client configuration of the cache device or devices or the read cache enabled SAN device or devices after the package is migrated and the etcdd device is configured, see DS8870 etcadmin -a shutdown command. v DS8870 storage devices that support Easy Tier Server must be configured on an Easy Tier Server client system. v The reserve_policy attribute of the AIX host device must be set to no_reserve if the DS8870 storage device will enable the read cache function. This procedure applies to installing the AIX LPP install image bos.etcachedd.rte. Table 4 on page 6 lists the files that are added to the system during installation. Copyright IBM Corp

12 Table 4. Files added during installation of the Easy Tier Server client software File name defetcdd cfgetcdd ucfgetcdd etcdd etcurh etccache etctsm etcreg etcsyslib etcdaemon etcadmin etcras Description This file defines the method of the Easy Tier Server etcdd device. This file configures the method of the Easy Tier Server etcdd device. This file unconfigures the method of the Easy Tier Server etcdd device. The Easy Tier Server device driver. The Easy Tier Server cache I/O handler. The Easy Tier Server cache manager. The Easy Tier Server clustering. The Easy Tier r Server registry. The Easy Tier r Server shared library. The Easy Tier Server daemon. The Easy Tier Server administrator CLI program. The Easy Tier Server RAS program. 1. Navigate to the directory that contains the bos.etcachedd install image, or load the compact disc into the CD-ROM drive. 2. Log in as the root user and issue the smitty install command. 3. Enter the path to the install image or the CD/DVD device that contains the CD/DVD media. 4. Follow the smitty install instructions to install the bos.etcachedd.rte package. When the installation is complete, the installation status is displayed as either OK or Failed. If the status is Failed, scroll through the details to locate the root cause of the failure. Correct the issue and restart the installation. Note: You can also use the installp command from the AIX command line to install the AIX LPP install image. To use the installp command, you must have a.toc file generated in the directory where the bos.etcachedd.rte package is located. To generate a.toc file, a. Type the following command and then press Enter: inutoc. b. Type the following command and then press Enter: installp -acgx -d dir bos.etcachedd Verifying the Easy Tier Server client software installation After you install or upgrade Easy Tier Server client software, you verify the installation. To verify that the Easy Tier Server client software is successfully installed, issue the following command: lslpp -l grep bos.etcachedd The command output is as follows: bos.etcachedd.rte W.X.Y.Z COMMITTED Easy Tier Server bos.etcachedd.rte W.X.Y.Z COMMITTED Easy Tier Server Note: In the output, W.X.Y.Z represents the VRMF number of the package. 6 Easy Tier Server

13 Chapter 4. Configuring, verifying, and unconfiguring the Easy Tier Server client Follow these procedures to configure, verify, and unconfigure the Easy Tier Server client software on an AIX system. Configuring the Easy Tier Server client software Complete the following steps to configure the Easy Tier Server client on an AIX system that has AIX6.1 TL8 or later, or AIX7.1 TL 2 or later installed. 1. To configure the Easy Tier Server client, you can either restart the system or issue the cfgmgr command to configure and load all Easy Tier Server kernel extensions. To verify the configuration, see Verifying the Easy Tier Server client software installation. 2. If the configuration methods in Step 1 are not successful, you can manually define and configure the Easy Tier Server client driver (etcdd), with debug activated to locate the failure. Follow these steps: a. Issue the /lib/methods/defetcdd command to define the Easy Tier Server etcdd device. b. Issue the /lib/methods/cfgetcdd -l etcdd command to configure the Easy Tier Server client driver etcdd device, which loads and configures all the Easy Tier Server client kernel extensions into the system kernel. Note: To activate the cfgetcdd/ucfgetcdd debug, add an additional option flag to the command of the following commands: v cfgetcdd v ucfgetcdd See the following examples. v /lib/methods/cfgetcdd -l etcdd -v 4488 v /lib/methods/ucfgetcdd -l etcdd -v 4488 You can issue the mkdev -l etcdd command instead of the cfgetcdd to configure the etcdd device. However, the mkdev -l etcdd command does not provide the option flag to support the debug function. After the configuration is complete, you must verify that the Easy Tier Server client software is configured successfully and that the system is ready to enable the Easy Tier Server function to SAN devices. Verifying the Easy Tier Server client software configuration The Easy Tier Server client software must be successfully configured before you can enable the read cache function on DS8870 SAN devices that are configured to support Easy Tier Server. 1. To verify that the Easy Tier Server driver etcdd device was successfully configured, issue the following command: lsdev -Ct etcdd The command produces the following output: etcdd Available Easy Tier Cache Parent If the etcdd device is not in the Available state, the Easy Tier Server client software configuration failed. If the configuration failed, run the configure method manually, with the debug flag activated, to determine where the configuration failed. See Configuring the Easy Tier Server client software. Copyright IBM Corp

14 2. To verify that the Easy Tier Server daemon is running, issue the following command: lssrc -s etcdaemon The command produces the following output: Subsystem Group PID Status etcdaemon etcdaemon_pid active If the etcdaemon does not start, the status is inoperative. Inoperative status indicates that the Easy Tier Server kernel extensions failed to load into the kernel and the Easy Tier Server client software configuration failed. Note: Easy Tier Server daemon is designed to be started or stopped by the Easy Tier Server client driver configuration and un-configuration methods. Do not issue command to manually start or stop the Easy Tier Server daemon. If the Easy Tier Server daemon is not in the expected state, contact IBM support and report the problem. 3. If you are migrating or updating the Easy Tier Server client software and, before the installation, you issued the etcadmin -a shutdown -s <user_choice> command to save the configuration of the Easy Tier Server cache device or the enabled read cache devices, or both, the saved Easy Tier Server configuration should be automatically restored during the etcdd device configuration. Issue the following commands to verify that the saved cache device or enabled read cache devices, or both, are correctly restored: v etcadmin -a list If the cache device configuration was saved during the shutdown and is now restored, the command output lists the Flash-based devices. If the Flash-based devices are not listed as expected, or listed incorrectly, the previous cache device configuration was not restored successfully. Contact IBM support for assistance. v etcadmin -a query If the enabled read cache device configuration was saved during the shutdown and is now restored, the command output lists all previously enabled read cache SAN devices. If the enabled read cache devices are not listed as expected, or listed incorrectly, the previous enabled read cache device configuration was not restored successfully. Contact IBM support for assistance. Unconfiguring the Easy Tier Server client software You can unconfigure the Easy Tier Server client software either manually or by issuing the etcadmin shutdown command. Issuing the etcadmin shutdown command provides the option to save the current Easy Tier Server configuration so that the configuration can be automatically restored during the next Easy Tier Server etcdd device configuration. Manually unconfiguring Easy Tier Server client software The manual unconfiguration method does not save the currently configured cache device and enabled read cache devices information. Therefore, during the next Easy Tier Server device configuration, all current cache device and enabled read cache device configurations are lost. Before you unconfigure the Easy Tier Server client software on a client system, you must stop (disable) the read cache function of all DS8870 SAN devices. Issue the following command: etcadmin -a stopall To unconfigure the Easy Tier Server client software, issue the following command: rmdev -dl etcdd Note: If read cache enabled SAN devices exist on the cache client system, the unconfiguration command fails. 8 Easy Tier Server

15 Verifying the Easy Tier Server client software unconfiguration You issue two commands to verify that the Easy Tier Server etcdd device was successfully unconfigured. 1. Issue the following command: lsdev -Ct etcdd Ensure that the etcdd device does not exist on the system. 2. Issue the following command: lssrc -s etcdaemon Ensure that the etcdaemon status is set to inoperative. If the status is displayed as stopping, the etcdaemon failed to stop. Contact IBM support for assistance. Chapter 4. Configuring, verifying, and unconfiguring the Easy Tier Server client 9

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17 Chapter 5. Easy Tier Server operations Use the information in this section to understand I/O population from the DS8870 system to the host, the impact of high-density I/O population, I/O efficiency, determining cached and evicted data, the best practices of HBA implementation, and validating how local SSD devices can meet Easy Tier Server requirements. Using the Storage Tier Advisory Tool to monitor Easy Tier Server efficiency The Storage Tier Advisor Tool (STAT) processes data that is collected by Easy Tier and Easy Tier Server monitors. STAT version allows you to monitor Easy Tier Server coherency client I/O operations per second (IOPS) statistics for overall read IOPS and DAS cache hit ratio. The STAT Easy Tier summary report provides an overview of Easy Tier-monitored DS8870 extent pools and all Easy Tier Server coherency clients that are managed by a server. When the caching of DS8000 volumes is enabled on the Easy Tier Server coherency client, Easy Tier Server host content is added to the summary report. For more information about STAT, including download instructions, see the related concept. 1. To export the current DS8870 Easy Tier summary report, log on to the IBM System Storage DS Storage Manager. You can access the DS Storage Manager from your browser by using the IP_address:P_port on your DS8800 HMC. 2. Select Home > System Status. 3. Right-click the appropriate storage image in the list, and select Storage Image > Export Easy Tier Summary Report. The summary report is a collection of two heat data files in a zipped folder. STAT processes these heat data files and generates a graphical output. Important: The STAT output is based on data collected by the Easy Tier monitoring function and is created only after a data-collection period of at least 24 hours. Easy Tier Server information on STAT is available in the next report cycle after Easy Tier Server deployment on the Easy Tier Server coherency clients. 4. Unzip the heat data files and use them as input files for STAT.exe, using the following syntax: STAT.exe inputfile1 inputfile2 The index.html file in the STAT installation directory is updated with the new heat data. 5. Open the index.html file to view the summary report. The System Summary view shows the average read IOPS and DAS cache hit ratio for each coherency client in the last 24-hour data-collection time frame. It also shows the configured DAS cache size for each coherency client. 6. To view detailed information about each coherency client, click the World Wide Port Name (WWPN) that corresponds to a client in the Host ID column. The STAT IOPS count for Easy Tier Server coherency clients is the average of overall read IOPS for all DS8870 LUNs in a specific client, considering both DAS read IOPS and DS8870 read IOPS. Cache hit ratio is the percentage of the read IOPS responded by DAS cache. The summaries do not include write I/Os. Copyright IBM Corp

18 Because STAT breaks down the IOPS and cached hit ratio statistics in the LUN level, you can view the individual results for all DS8870 LUNs that are mapped to a specific coherency client. To view the detailed breakdown per LUN statistics, expand the Existing Attached Volume Status option. 12 Easy Tier Server

19 Chapter 6. etcadmin command Use the etcadmin command to display and manage Flash-based devices and SAN Easy Tier Server devices. Description You can use the etcadmin command to complete the following functions: v Create a cache device using a Flash-based device on an AIX Easy Tier Server client. v Add additional Flash-based devices to an existing cache device. v Remove the previously created client cache device. v Start (enable) the SAN storage device read cache function on one SAN storage device or on a set of SAN storage devices. v Stop (disable) the SAN storage device read cache function on one SAN storage device or on a set of SAN storage devices. v Stop (disable) the read cache function of all SAN storage devices. v Query all enabled read cache enabled SAN storage devices. v List all Flash-based devices that belong to a cache device on an AIX Easy Tier Server client. v Display the I/O statistics of a SAN read cache enabled device. v Shut down and remove the Easy Tier Server client driver and save the current Easy Tier Server client configuration based on the user's input. v Configure the Easy Tier Server client driver while automatically restoring the previously saved Easy Tier Server client configurations based on the user's input. The following commands manage the Easy Tier Server driver: v etcadmin -a shutdown v etcadmin -a cfgetcdd Easy Tier Server caches I/O reads from specified drives. The following commands manage the cache that is used to cache the data from these I/O reads: v etcadmin -a create v etcadmin -a add v etcadmin -a destroy v etcadmin -a list The following commands manage the actual caching of data to the specified drives (the drives that Easy Tier Server is monitoring and caching): v etcadmin -a start v etcadmin -a stop v etcadmin -a stopall v etcadmin -a query v etcadmin -a iostat Note: v The device logical name must start with /dev/ when you specify it with commands to manage the Flash-based devices. Copyright IBM Corp

20 v The device logical name must start with hdisk if you use the commands to manage the SAN device read caching function. etcadmin -a create command Use the etcadmin -a create command to create a cache device with a Flash-based device on an AIX Easy Tier Server client. If the command completes successfully, a cache_dev device attribute with a value of yes (active) is created or updated for the Flash-based device. etcadmin -a create -d /dev/flash Cache device Parameters Flash Cache device A Flash-based device. The logical device name must start with /dev/ You can create only one Flash-based device when you use the etcadmin -a create command. In this example, device hdisk98 is an EXP30 SSD device that is configured on an AIX Easy Tier Server client. etcadmin -a create -d /dev/hdisk98 etcadmin -a add command Use the etcadmin -a add command to add another Flash-based device to an existing cache. If the command completes successfully, a cache_dev device attribute with the value of yes (active) is created or updated. etcadmin -a add -d /dev/flash Cache device Parameters Flash Cache device A Flash-based device. The logical device name must start with /dev/. You can add only one Flash-based device each time you use the etcadmin -a add command. In this example, device hdisk99 is an EXP30 SSD device that is configured on an AIX Easy Tier Server client. etcadmin -a add -d /dev/hdisk99 etcadmin -a destroy command Use the etcadmin -a destroy command to remove the Easy Tier Server client cache that was previously created. If the command completes successfully, the cache_dev attributes of all Flash-based devices are updated to the value of no (non-active). etcadmin -a destroy 14 Easy Tier Server

21 Parameters This command has no parameters, as shown in the example. etcadmin -a destroy etcadmin -a start command Use the etcadmin -a start command to start (enable) the read cache function on a single SAN device or on a set of SAN devices. To start the function on a single SAN device, issue the command with the -d option. To start the function on a set of SAN devices, issue the command with the -D option. If the command completes successfully, a device read_cache attribute with a value of enabled is created or updated. An error message is displayed if the command fails on a SAN device. Starting the read cache function on a single SAN device etcadmin -a start -d SAN_device Parameters SAN_device The SAN device must be a DS8870 storage device that is configured on an AIX Easy Tier Server client. The client must have read cache enabled. Type the SAN device logical name as hdiskx. The /dev/ prefix is not required. etcadmin -a start -d hdisk10 Starting the read cache function on a set of SAN devices Note: A set of SAN devices consists of devices with logical names between hdiskx and hdisky. For example, if hdiskx is hdisk10 and hdisky is hdisk20, then the set of hdisks includes hdisk10, hdisk11, hdisk12, hdisk13, hdisk14, hdisk15, hdisk16, hdisk17, hdisk18, hdisk19, and hdisk20. etcadmin -a start -D SAN_device1 SAN_device2 Parameters SAN_device1 SAN_device2 When you enter two SAN logical device names, this command applies to all devices whose logical device index numbers fall within the range of these two device index numbers. Each SAN device must be a DS8870 storage device that is configured on an AIX Easy Tier Server client. The client must have read cache enabled. Type the SAN device logical name as hdiskx. The /dev/ prefix is not required. In this example, the command starts all SAN devices in the range hdisk10 - hdisk30. etcadmin -a start -D hdisk10 hdisk30 Chapter 6. DS8870 etcadmin command 15

22 etcadmin -a stop command Use the etcadmin -a stop command to stop (disable) the read cache function on a single SAN device or on a set of SAN devices. To stop the function on a single SAN device, issue the command with the -d option. To stop the function on a set of SAN devices, issue the command with the -D option. If the command completes successfully, the SAN device read cache attribute is updated with the value of disabled. An error message is displayed if the command fails on a SAN device. Stopping the read cache function on a single SAN device etcadmin -a stop -d SAN_device Parameters SAN_device The SAN device must be a DS8870 storage device that is configured on an AIX Easy Tier Server client. The client must have read cache enabled. Type the SAN device logical name as hdiskx. The /dev/ prefix is not required. etcadmin -a stop -d hdisk10 Note: You can issue the etcadmin -a stopall command to stop (disable) the read cache function on all SAN devices. See etcadmin -a stopall command. Stopping the read cache function on a set of SAN devices Note: A set of SAN devices consists of devices with logical names between hdiskx and hdisky. For example, if hdiskx is hdisk10 and hdisky is hdisk20, then the set of hdisks includes hdisk10, hdisk11, hdisk12, hdisk13, hdisk14, hdisk15, hdisk16, hdisk17, hdisk18, hdisk19, and hdisk20. etcadmin -a stop -D SAN_device1 SAN_device2 Parameters SAN_device1 SAN_device2 When you enter two SAN logical device names, this command applies to all devices whose logical device index numbers fall within the range of these two device index numbers. Each SAN device must be a DS8870 storage device that is configured on an AIX Easy Tier Server client. The client must have read cache enabled. Type the SAN device logical name as hdiskx. The /dev/ prefix is not required. In this example, the command stops all SAN devices in the range hdisk10 - hdisk30. etcadmin -a stop -D hdisk10 hdisk30 Note: You can issue the etcadmin -a stopall command to stop (disable) the read cache function on all SAN devices. See DS8870 etcadmin -a stopall command. 16 Easy Tier Server

23 etcadmin -a stopall command Use the etcadmin -a stopall command to disable all read cache enabled SAN devices on an Easy Tier Server client. If the command completes successfully, it updates the read cache attribute of each SAN device to disabled. An error message is displayed if the command fails on a SAN device. etcadmin -a stopall Parameters This command has no parameters, as shown in the example. etcadmin -a stopall etcadmin -a query command Use this command to display all read cache enabled SAN devices on an AIX Easy Tier Server client. The command displays a different mark for each read cache enabled SAN device, as shown in the example. etcadmin -a query Parameters This command has no parameters, as shown in the following example. etcadmin -a query Total cache enabled devices is * : indicates SAN device read_cache has started $ : indicates SAN device read_cache has started in shared mode : indicates SAN device read_cache has not started ~ : indicates failing to get SAN device read_cache status Device name ============================== *hdisk6 hdisk7 *hdisk8 *hdisk9 hdisk10 ~hdisk11 hdisk12 *hdisk13 *hdisk14 etcadmin -a list command Use the etcadmin -a list command to list all Flash-based devices that belong to a cache device on an AIX Easy Tier Server client. etcadmin -a list Chapter 6. DS8870 etcadmin command 17

24 Parameters This command has no parameters, as shown in the example. In this example, all devices that belong to the cache device are listed. etcadmin -a list Device Name Caching Capacity (bytes) /dev/hdisk /dev/hdisk etcadmin -a iostat command Use this command to display I/O statistics, including the read/write I/O to SAN storage and read I/O to the cache device, for a read cache enabled SAN devices on an AIX Easy Tier Server client. etcadmin -a iostat -d SAN_device Parameters SAN_device The SAN device must be a DS8870 storage device configured on an Easy Tier Server client, with the read_cache attribute value set to enabled. Type the SAN device logical name as hdiskx. The /dev/ prefix is not required. If the command completes successfully, the following output displays. etcadmin -a iostat -d hdisk30 ETCC Device I/O Statistics -- hdisk Read Count: Write Count: Read Hit Count: Partial Read Hit Count: 105 Read Bytes Xfer: Write Bytes Xfer: Read Hit Bytes Xref: Partial Read Hit Bytes Xfer: Promote Read Count: 785 Promote Read Bytes Xfer: Report field definitions Read Count This is the total number of read operations that were issued to the driver. This number is the combination of all applications that issued read commands that were sent to the SAN device or to cache. This number has no relation to the size of the requests. It is the count of separate read requests. Write Count This is the total number of write operations that were issued to the driver. This number has no relation to the size of the requests. It is the actual count of separate write requests. Read Hit Count This is the total number of read operations that were issued to the driver that were full read hits. The 18 Easy Tier Server

25 full read hit is a count of instances in which a read request included all data requested in cache. This number has no relation to the size of the requests. It is the actual count of separate Read requests. This value is already included with the Read Count. Partial Read Hit Count This is the total number of read operations that were issued to the driver that were partial read hits. The partial read hit is a number of instances in which a read request had part, but not all, of the data requested in cache. The remainder of the data not available in cache must be acquired from SAN devices. This number has no relation to the size of the requests. It is the actual count of separate Read requests. This value is already included with the Read Count. Read Bytes Xfer This is the total number of bytes that were read through the driver. This number is the combination of all read commands issued from the application into the driver. This is the total byte count of read hits and partial read hits. Write bytes Xfer This is the total number of bytes that were written through the driver. This number is the combination of bytes from all write commands issued from the application into the driver. Read Hit Bytes Xfer This is the total number of bytes that were read through the driver that were full read hits. Partial Read Hit Bytes Xfer This is the total number of bytes that were read through the driver that were partial read hits. Promote Read Count This is the total number of read commands that were issued to the SAN device as part of the promote into cache. This number is not tied to the number of promotes because a1mbreadpromote might be divided into multiple read requests if the maximum transfer size to the SAN disk is less than the 1 MB fragment size. Promote Read Bytes Xfer This is the total number of bytes that were read from the SAN device for promotes. etcadmin -a shutdown command Use this command to stop (disable) all read cache enabled SAN devices, remove the cache device, and unconfigure and remove the etcdd device from the Easy Tier Server client. You can use the -s option to save the current cache device configuration or read cache enabled SAN device configuration, or both, to files, based on your input. The saved Easy Tier Server client configuration files are used to restore the Easy Tier Server client configuration during the next Easy Tier Server etcdd device configuration or client software package migration or upgrade. The following scenarios apply to restoring the saved Easy Tier Server client configuration file: v Unconfiguring or reconfiguring the etcdd device. The only method that can automatically restore a saved Easy Tier Server client configuration during an etcdd device configuration is issuing the etcadmin -a cfgetcdd command. Rebooting the system or issuing the cfgmgr command to configure the etcdd device does not restore a saved Easy Tier Server client configuration. v Migrating or upgrading the Easy Tier Server client package. After issuing the etcadmin -a shutdown command and migrating the Easy Tier Server client package, you can either reboot the system or issue the cfgmgr command to configure the etcdd device and automatically restore the saved Easy Tier Server client configuration. Do not issue the etcadmin -a cfgetcdd -r command if you are migrating or upgrading the Easy Tier Server client package. Note: Chapter 6. DS8870 etcadmin command 19

26 After the etcdd device is configured, regardless of the method that was used, the previously saved Easy Tier Server client configuration files will not exist on the client. The saved configuration files are used only once for restoring. etcadmin -a shutdown -s yes cacdev rdcac no Parameters yes This option saves both the Easy Tier Server client cache device and read cache enabled SAN devices configurations before the Easy Tier Server client driver is shut down. cacdev This option saves only the Easy Tier Server client cache device configuration before the Easy Tier Server client driver is shut down. rdcac This option saves only the Easy Tier Server client read cache enabled SAN device configurations before the Easy Tier Server client driver is shut down. no This option does not save the Easy Tier Server configuration before the Easy Tier Server client driver is shut down. etcadmin -a shutdown -s yes etcadmin -a cfgetcdd command Use this command to configure the Easy Tier Server etcdd device to the Available state. The command provides the option to automatically restore the previously saved Easy Tier Server configuration. If you wish to automatically restore a saved Easy Tier Server client configuration during the etcdd device configuration without the Easy Tier Server client package migration or upgrade, you must issue the etcadmin -a cfgetcdd -r command and provide the input for the -r option. Rebooting the system or issuing the cfgmgr command configures the etcdd device but does not restore the previously saved Easy Tier Server client configuration. Note: You can restore only what was saved by the etcadmin -a shutdown -s command. The etcadmin -a cfgetcdd command is used only to configure the etcdd device and automatically restore the saved Easy Tier Server client configuration without the Easy Tier Server client package migration or upgrade. If you migrated or upgraded the Easy Tier Server client package after issuing the etcadmin -a shutdown command, reboot the client system or run the cfgmgr command to configure the etcdd device and automatically restore the saved Easy Tier Server client configuration. etcadmin -a cfgetcdd -r yescacdevrdcacno Parameters yes This option restores both the Easy Tier Server client cache device and read cache enabled SAN device configuration during the etcdd device configuration.. cacdev This option restores only the Easy Tier Server client cache device configuration during the client etcdd device configuration. 20 Easy Tier Server

27 rdcac This option restores only the Easy Tier Server client read cache enabled SAN device or devices configuration during the client etcdd device configuration. no This option does not restore any Easy Tier Server client configuration during the client etcdd device configuration. In this example, only the Easy Tier Server client cache device configuration is restored during the client etcdd device configuration. etcadmin -a cfgetcdd -r cacdev Chapter 6. DS8870 etcadmin command 21

28 22 Easy Tier Server

29 Chapter 7. Easy Tier Server error-log descriptions View AIX error-log descriptions for DS8870 Easy Tier Server software on an AIX server. Message descriptions are listed for the following kernel extensions: v Easy Tier Server wrapper driver (etcdd) v Easy Tier Server register kernel extension (etcreg) v Easy Tier Server user request handler (etcurh) v Easy Tier Server cache directory (etccache) v Easy Tier Server coherency server manager (etctsm) Easy Tier Server wrapper driver error-log descriptions ETC_ETCDD_DEV2ETCDD Indicates that the first SAN device read cache function was enabled. As a result, the etcdd driver replaced the AIX disk driver READ, WRITE, and STRATEGY routine pointers in the AIX device switch table with the etcdd READ, WRITE, and STRATEGY routine pointers. ETC_ETCDD_DEV2DISK Indicates that the last SAN device read cache function was disabled. As a result, the etcdd driver restored the AIX disk driver READ, WRITE, and STRATEGY routine pointers in the AIX device switch table. ETC_ETCDD_ENAB_RDC Indicates that a SAN device read cache function is enabled. ETC_ETCDD_DISA_RDC Indicates that a SAN device read cache function is disabled. Easy Tier Server register kernel extension error-log descriptions ETC_REG_REGERR An attempt to load the etcreg driver failed because the registration key is in use by other kernel drivers. ETC_REG_UNREGERR An attempt to unload the etcreg driver failed because the registration key is in use by other kernel drivers, or because other Easy Tier Server component-specific handles are not valid. Easy Tier Server user request handler error-log descriptions ETC_URH_ERRFROMREG An attempt to load the etcurh driver failed because the etcreg driver did not provide the correct service handle to the etcurh driver. ETC_URH_REGFAIL An attempt to load the etcurh driver failed because the etcurh registration key was in use by some other kernel drivers. ETC_URH_UNREGFAIL An attempt to unload the etcurh driver failed because the etcurh registration key was in use by some other kernel drivers. ETC_URH_REG2TTFAIL An attempt to load the etcurh driver failed because the etcurh driver could not register with the etcdd driver. Copyright IBM Corp

30 ETC_URH_UNREG2TTFAIL An attempt to unload the etcurh driver failed because the etcdd driver did not cooperate in the unregistration process. ETC_URH_TTFUNCMISS The etcurh driver has exchanged function pointers with the etcdd driver, but at least one of the function pointers that were provided by the etcdd driver is not valid. ETC_URH_NOMEM The etcurh driver failed to allocate RAM or create a kernel thread from the kernel. ETC_URH_CACNOTSTART A SAN device was enabled for caching but the overall caching functionality has not yet been started in the etcurh driver. ETC_URH_NOLUNIDFOUND A request to enable caching for a device was passed to the etcurh driver, but the device does not have a valid SCSI LUN identifier. ETC_URH_ERRINVRANGE A cache data write to the cache-enabled SAN device resulted in an invalidate operation, but the cache invalidation failed. ETC_URH_WRONGFRAGSZ The etcurh driver requested the etccache driver for the current fragment size, but the fragment size value was less than or equal to 0 (zero). Easy Tier Server cache directory error-log descriptions ETC_CAC_SANRIOERR The Easy Tier Server coherency client tried to read data from a SAN volume to populate the cache, but the process returned from a SAN I/O error. The data was not populated into the cache. ETC_CAC_DASIOERR The Easy Tier Server coherency client cannot read data from a DAS device or write data to a DAS device because of an I/O error. In this case, the Easy Tier Server coherency client attempts to access the device with successive I/O requests until 1024 I/O errors have been encountered. ETC_CAC_TSMERR The ETC CAC module cannot communicate with the ETC TSM module. This might occur if the Easy Tier Server software is not configured or installed properly or if the user manually unloads the ETC TSM module. ETC_CAC_URHERR The ETC CAC module cannot communicate with the ETC URH module. This might occur if the Easy Tier Server software is not configured or installed properly or if the user manually unloads the ETC URH module. ETC_CAC_REGERR The ETC CAC module cannot communicate with the ETC REG module. ETC_CAC_TTDAEMONERR The Easy Tier Server ETC CAC module cannot communicate with the user-space daemon. Typically, this means that the user-space daemon remains inactive and should be restarted. While this state persists, no new data is populated into the cache, although the cache remains operational. ETC_CAC_NOMEM There is not enough memory for the ETC CAC module to allocate internal structures. ETC_CAC_INTRNLERR An internal error in the Easy Tier Server coherency client has been encountered. The integrity of 24 Easy Tier Server

31 data served from the cache cannot be guaranteed from this point forward and therefore the Easy Tier Server coherency client should be uninstalled immediately. ETC_CAC_DASTOOSMALL The user attempted to create Easy Tier Server on a device that does not have adequate capacity. The device must be at least 1MB in size for the cache to be created. ETC_CAC_WARM Easy Tier Server is full (warm). This message is informational only and does not imply an error scenario, however, the working set of the current workload is larger than the size of the cache and therefore the user should add more DAS capacity to the cache to obtain maximum performance. ETC_CAC_DASDEVABB Easy Tier Server attempted to access the DAS device beyond its limits and indicated an internal error. The integrity of data served from the cache cannot be guaranteed from this point forward and therefore the Easy Tier Server coherency client should be uninstalled immediately. ETC_CAC_DASTOOSLOW Easy Tier Server detected that a DAS device was being overutilized, which caused a long response time. In this case, some of the accesses continue to be served from the SAN, even though the target data might be located in the cache. ETC_CAC_CACHEFENCED Easy Tier Server detected that a DAS device went bad or missing and fenced the cache. Therefore no further requests will be attempted to be served from the cache. The cache needs to be destroyed and re-created after the hardware configuration has been restored. Easy Tier Server coherency server manager error-log descriptions ETC_TSM_NOMEM The system is low on memory and the Easy Tier Server module is unable to allocate memory for its internal data structures. ETC_TSM_QTASKFAIL The Easy Tier Server module is unable to add a task to the OS task queues, probably because the task already exists on the queue. ETC_TSM_SCSICMDFAIL An Easy Tier Server SCSI command has failed. This might be a protocol error or it might be caused by a communication failure between the host and the storage. Depending upon the actual SCSI command and system state, Easy Tier Server automatically tries the command again (immediately or at a later time). ETC_TSM_NOLOCK Indicates that the host currently does not hold any volume locks and is not caching any data. This is an informational message. ETC_TSM_LRCERR The LRC value that was computed by the host for the server advice does not match the LRC value that was provided by the server. This indicates a communication error or a protocol mismatch. The advice provided by the server is discarded. ETC_TSM_NOPATH Easy Tier Server is unable to query the paths that are available for a volume. ETC_TSM_INVADVICLEN The server has provided an advice length to the Easy Tier Server host component that is not valid. Chapter 7. Easy Tier Server error-log descriptions 25