The Host Server. HPUX Configuration Guide. August The authority on real-time data

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1 The Host Server HPUX Configuration Guide August 2018 This guide provides configuration settings and considerations for Hosts running HPUX with SANsymphony. Basic HPUX storage administration skills are assumed including how to connect to iscsi and Fibre Channel target ports and the discovering, mounting and formatting of disk devices. The authority on real-time data

2 Table of contents Changes made to this document 3 HPUX compatibility list 4 HPUX operating system versions 4 Qualified vs. Not Qualified vs. Not Supported 5 The DataCore Server's Settings 6 Operating System Type 6 Port roles 6 Multipathing 6 ALUA support 6 Serving Virtual Disks 6 The HPUX Host's settings 8 Physical Volume timeout 8 Known Issues 9 Appendix A 10 Preferred Server & Preferred Path settings 10 Appendix B 11 Reclaiming Storage from Disk Pools 11 Previous changes 13

3 Changes made to this document The most recent version of this document is available from here: All changes since February 2018 Updated HPUX compatibility list Version with SANsymphony 10.x using ALUA has been changed from Not Supported to Not Qualified thereby allowing self-qualification. For previous changes made to this document please see page 13 Page 3

4 HPUX compatibility list HPUX operating system versions SANsymphony 9.0 PSP 4 Update 4 (1) SANsymphony 10.0 (all versions) HPUX WITH ALUA WITHOUT ALUA WITH ALUA WITHOUT ALUA or earlier Not Supported Not Supported Not Supported Not Supported Not Supported Not Qualified Not Qualified Qualified Notes: Qualified vs. Not Qualified vs. Not Supported See the next page for definitions. DataCore Server Port connections For HPUX hosts, only Fibre Channel Front-End connections are supported. Front-End iscsi connections are not supported. SCSI UNMAP There is no support for SCSI UNMAP from HPUX hosts. 1 Earlier versions are End of Life. See: Page 4

5 HPUX compatibility lists Qualified vs. Not Qualified vs. Not Supported Qualified This combination has been tested by DataCore and all the host-specific settings listed in this document applied using non-mirrored, mirrored and Dual Virtual Disks. Not Qualified This combination has not yet been tested by DataCore using Mirrored or Dual Virtual Disks types. DataCore cannot guarantee 'high availability' (failover/failback, continued access etc.) even if the host-specific settings listed in this document are applied. Self-qualification may be possible please see Technical Support FAQ #1506 Mirrored or Dual Virtual Disks types are configured at the users own risk; however, any problems that are encountered while using HPUX versions that are 'Not Qualified' will still get root-cause analysis. Non-mirrored Virtual Disks are always considered 'Qualified' - even for 'Not Qualified' combinations of HPUX/SANsymphony. Not Supported This combination has either failed 'high availability' testing by DataCore using Mirrored or Dual Virtual Disks types; or the operating System's own requirements/limitations (e.g. age, specific hardware requirements) make it impractical to test. DataCore will not guarantee 'high availability' (failover/failback, continued access etc.) if the host-specific settings listed in this document are applied. Mirrored or Dual Virtual Disks types are configured at the users own risk. Self-qualification is not possible. Mirrored or Dual Virtual Disks types are configured at the users own risk; however, any problems that are encountered while using HPUX versions that are 'Not Supported' will get best-effort Technical Support (e.g. to get access to Virtual Disks) but no root-cause analysis will be done. Non-mirrored Virtual Disks are always considered 'Qualified' even for 'Not Supported' combinations of HPUX/SANsymphony. HPUX versions that are End of Support Life Self-qualification may be possible for versions that are considered Not Qualified by DataCore but only if there is an agreed support contract with HP. Please contact DataCore Technical Support before attempting any self-qualification of For any problems that are encountered while using HPUX versions that are EOSL with DataCore Software, only best-effort Technical Support will be performed (e.g. to get access to Virtual Disks). Root-cause analysis will not be done. Non-mirrored Virtual Disks are always considered 'Qualified'. Page 5

6 The DataCore Server's Settings Operating System Type When registering the Host running HP-UX choose the HP HP-UX menu option. Port roles Ports used for serving Virtual Disks to Hosts should only have the Front End (FE) role enabled. Mixing other Port Role types may cause unexpected results as Ports that only have the FE role enabled will be turned off when the DataCore Server software is stopped (even if the physical server remains running). This helps to guarantee that any Hosts do not still try to access FE Ports, for any reason, once the DataCore Software is stopped but where the DataCore Server remains running. Any Port with the Mirror and/or Back End role enabled do not shut off when the DataCore Server software is stopped but still remain active. Multipathing The Multipathing Support option should be enabled so that Mirrored Virtual Disks or Dual Virtual Disks can be served to Hosts from all available DataCore FE ports. Also see the Multipathing Support section from the SANsymphony Help: WebHelp/Hosts.htm Non-mirrored Virtual Disks and Multipathing Non-mirrored Virtual Disks can still be served to multiple Hosts and/or multiple Host Ports from one or more DataCore Server FE Ports if required; in this case the Host can use its own multipathing software to manage the multiple Host paths to the Single Virtual Disk as if it was a Mirrored or Dual Virtual Disk. ALUA support ALUA (Asymmetrical Logical Unit Access) is not supported. Serving Virtual Disks For the first time DataCore recommends that before serving Virtual Disks for the first time to a Host, that all DataCore Front-End ports on all DataCore Servers are correctly discovered by the Host first. Then, from within the SANsymphony Console, the Virtual Disk is marked Online, up to date and that the storage sources have a host access status of Read/Write. To more than one Host port DataCore Virtual Disks always have their own unique Network Address Authority (NAA) identifier that a Host can use to manage the same Virtual Disk being served to multiple Ports on the same Host Server and the same Virtual Disk being served to multiple Hosts. While DataCore cannot guarantee that a disk device's NAA is used by a Host's operating system to identify a disk device served to it over different paths generally we have found that it is. And while there is sometimes a convention that all paths by the same disk device should Page 6

7 The DataCore Server's settings always using the same LUN 'number' to guarantees consistency for device identification, this may not be technically true. Always refer to the Host Operating System vendor s own documentation for advice on this. DataCore's Software does, however always try to create mappings between the Host's ports and the DataCore Server's Front-end (FE) ports for a Virtual Disk using the same LUN number where it can. The software will first find the next available (lowest) LUN 'number' for the Host- DataCore FE mapping combination being applied and will then try to apply that same LUN number for all other mappings that are being attempted when the Virtual Disk is being served. If any Host-DataCore FE port combination being requested at that moment is already using that same LUN number (e.g. if a Host has other Virtual Disks served to it from previous) then the software will find the next available LUN number and apply that to those specific Host-DataCore FE mappings only. Also See Registering Hosts Changing Virtual Disk Settings - SCSI Standard Inquiry Page 7

8 The HPUX Host's settings Physical Volume timeout Set the timeout value to 60 seconds using the following commands: pvchange t IO_timeout physical_volume_path pvchange t 60 /dev/dsk/c#t#d# Where c#t#d# is the device identifier given to the DataCore Virtual Disk device Page 8

9 Known Issues The following is intended to make DataCore Software customers aware of any issues that may affect performance, access or generally give unexpected results under certain conditions when HPUX Hosts are used with SANsymphony. Some of the issues here have been found during DataCore s own testing but many others are issues reported by DataCore Software customers, where a specific problem had been identified and then subsequently resolved. DataCore cannot be held responsible for incorrect information regarding HP products. No assumption should be made that DataCore has direct communication with HP regarding the issues listed here and we always recommend that users contact their HP Support provider directly to see if there are any updates or fixes since they were reported to us. For Known issues for DataCore s own Software products, please refer to the relevant DataCore Software Component s release notes. Multiple roles assigned to SANsymphony ports serving Virtual Disks to the Host can lead to misleading statuses on HP-UX If a SANsymphony Server's port, used for serving Virtual Disks to the HP-UX host, has either the Back-end (BE) or Mirror (MR) roles set - in addition to Front-end (FE) role - then the HP- UX host may show discovered LUNs with a status of 'NO-HW' (no hardware) after any subsequent path failures. This is cosmetic and has no functional impact. Remove any BE or MR roles from all ports used to serve Virtual Disks to HP-UX Hosts. Page 9

10 Appendix A Preferred Server & Preferred Path settings Without ALUA enabled If Hosts are registered without ALUA support, the Preferred Server and Preferred Path settings will serve no function. All DataCore Servers and their respective Front End (FE) paths are considered equal. It is up to the Host s own Operating System or Failover Software to determine which DataCore Server is its preferred server. With ALUA enabled ALUA is not supported for HPUX Hosts. Also see Preferred Servers and Preferred Paths from: Page 10

11 Appendix B Reclaiming Storage from Disk Pools How much storage will be reclaimed? This is impossible to predict. SANsymphony can only reclaim Storage Allocation Units that have no block-level data on them. If a Host write its data all over its own filesystem, rather than contiguously, the amount of storage that can be reclaimed may be significantly less than expected. Defragmenting data on Virtual Disks It may be possible to use a Host s own defragmentation tools to consolidate data spread out all over the host s filesystem but care should be taken as even more storage may be allocated while the existing data is defragmented. Once any defragmentation is completed then additional steps will need to wipe the free filesystem space on the host and then use SANsymphony s Manual Reclamation. Notes on SANsymphony's Reclamation feature Automatic Reclamation SANsymphony checks for any zero write I/O as it is received by the Disk Pool and keeps track of which block addresses they were sent to. When all the blocks of an allocated SAU have received zero write I/O, the storage used by the SAU is then reclaimed. Mirrored and replicated Virtual Disks will mirror/replicate the zero write I/O so that storage can be reclaimed on the mirror/replication destination DataCore Server in the same way. Manual Reclamation SANsymphony checks for zero block data by sending read I/O to the storage. When all the blocks of an allocated SAU are detected as having zero data on them, the storage used by the SAU is then reclaimed. Mirrored Virtual Disks will receive the manual reclamation request on all DataCore Servers involved in the mirror configuration at the same time and each DataCore Server will read from its own storage. The Manual reclamation request is not sent to replication destination DataCore Servers from the source. Replication destinations will need to be manually reclaimed separately. Page 11

12 Appendix B Reclaiming Storage from Disk Pools Reclaiming storage on the Host manually A suggestion would be to create a sparse file of an appropriate size and write zeroes it using the dd command. Here is an example with a 2TB sparse file: dd if=/dev/zero of=my_sparse_file bs=1024 count= Also see Auto-reclamation of unused SAUs Reclaiming Unused Virtual Disk Space in Disk Pools: Page 12

13 Previous changes General This document has been reviewed for SANsymphony 10.0 PSP 7. No additional settings or configurations are required. February 2018 Removed Appendix B Configuring Disk Pools The information here has been removed as it is now superseded by the information in: The DataCore Server- Best Practice Guidelines What was previously 'Appendix C' has now been moved to 'Appendix B'. Updated This document has been reviewed for SANsymphony 10.0 PSP 7. No updates were required. November 2017 Updated This document has been reviewed for SANsymphony 10.0 PSP 6. No updates were required. May 2017 Updated Appendix C - Reclaiming storage Automatic and Manual reclamation These two sections have been re-written with more detailed explanations and technical notes. November 2016 Updated This document has been reviewed for SANsymphony 10.0 PSP 5. No updates were required. July 2016 October 2015 Added A new section: Known Issues Multiple roles assigned to SANsymphony-V ports serving Virtual Disks to the Host can lead to misleading statuses on HP-UX. This was originally documented as June 2015 Added List of qualified HP-UX Versions - Notes on qualification This section has been updated and new information added regarding the definitions of all qualified, unqualified and not supported labels. A new section on HP-UX versions that are no longer in development has also been added at the end of this section. Page 13

14 Previous changes February 2015 Updated This document now combines all of DataCore s HP-UX-related information from older Technical Bulletins into a single document including: Technical Bulletin 8: Formatting Host s File Systems on Virtual Disks created from Disk Pools Technical Bulletin 11: Disk Timeout Settings on Hosts Technical Bulletin 16: Reclaiming Space in Disk Pools Added List of qualified HP-UX Versions Added new tables to show which versions are explicitly qualified, unqualified and not supported with either SANsymphony-V 9.x or 10.x, and if the configuration is with or without ALUA enabled Hosts. Note that SANsymphony-V 8.x is now considered End of Life. Appendix A This section gives more detail on the Preferred Server and Preferred Path settings with regard to how it may affect a Host. Appendix B This section incorporates information regarding Reclaiming Space in Disk Pools (from Technical Bulletin 16) that is specific to HP-UX Hosts. Page 14

15 The authority on real-time data Copyright 2018 by DataCore Software Corporation. All rights reserved. DataCore, the DataCore logo and SANsymphony are trademarks of DataCore Software Corporation. Other DataCore product or service names or logos referenced herein are trademarks of DataCore Software Corporation. All other products, services and company names mentioned herein may be trademarks of their respective owners. ALTHOUGH THE MATERIAL PRESENTED IN THIS DOCUMENT IS BELIEVED TO BE ACCURATE, IT IS PROVIDED AS IS AND USERS MUST TAKE ALL RESPONSIBILITY FOR THE USE OR APPLICATION OF THE PRODUCTS DESCRIBED AND THE INFORMATION CONTAINED IN THIS DOCUMENT. NEITHER DATACORE NOR ITS SUPPLIERS MAKE ANY EXPRESS OR IMPLIED REPRESENTATION, WARRANTY OR ENDORSEMENT REGARDING, AND SHALL HAVE NO LIABILITY FOR, THE USE OR APPLICATION OF ANY DATACORE OR THIRD PARTY PRODUCTS OR THE OTHER INFORMATION REFERRED TO IN THIS DOCUMENT. ALL SUCH WARRANTIES (INCLUDING ANY IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT, FITNESS FOR A PARTICULAR PURPOSE AND AGAINST HIDDEN DEFECTS) AND LIABILITY ARE HEREBY DISCLAIMED TO THE FULLEST EXTENT PERMITTED BY LAW. No part of this document may be copied, reproduced, translated or reduced to any electronic medium or machinereadable form without the prior written consent of DataCore Software Corporation