Tips & Tricks. Bitmap or Delta sync What s the difference? Demystifying VRA compression And how to boost it

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2 Tips & Tricks Bitmap or Delta sync What s the difference? Demystifying VRA compression And how to boost it Logs, logs, and more logs How can you exit from that business? Networks Can t live without them, and they can cause stress! Miscellaneous tools we all use Saves us precious time and dirty work Zerto Cmdlets Crack the shell with the Zerto PowerShell SnapIn! Collaborate! 2

3 Delta Sync Synopsis: A Delta Sync occurs when Zerto needs to verify the consistency of the source (protected) and recovery disks. Can occur if: - Reverse Protection is enabled for a Failover or Move operation. - VPGs are created with pre-seed disks. - Reverting a protected VM to a snapshot triggering an inconsistency. During a Delta Sync, the VPG will go through an md5 checksum comparison between the protected and recovery disks and writes any missing blocks. 3

4 Bitmap Sync Synopsis: A Bitmap Sync occurs when the VRAs cannot send the protected I/Os to the recovery site. We will discuss the various reasons in the next slide. Zerto uses a bit-map to track the changes between the protected and recovery disks so that when VRA connectivity is restored - the blocks that changed on the protected site during the disconnection can be quickly identified and send to the relevant recovery volumes. 4

5 Some different scenarios include, but not limited to, the following: 1] Disconnection between VRAs. Bitmap Sync Reasons: 2] The journal or recovery volumes encounter storage errors. 3] The source (protected) storage encounters I/O issues or if errors are returned from the storage. 4] The VRA is unable to send Write I/Os fast enough. 5] The network is unable to sent protected IOs fast enough. 6] The recovery storage is not fast enough to handle the protected IOs. 5

6 VRA Compression Rates: How does compression work with Zerto? 1] The VRAs intercepts and buffers the protected I/Os at the host level. 2] The VRA compresses these I/Os using CPU resources. 3] The VRA sends compressed I/Os across the WAN to the recovery VRA where the I/Os are written to Journal. 4] The VRA decompresses the protected I/Os and applies them to the recovery mirror. 6

7 Concerns with VRA Compression Rates: When can VRAs experience issues with compression? The main reason a VRA would have issues with compression is if there are CPU resources are constrained on the protected VRA. Note that decompression of I/Os does not take up as CPU cycles as compression. many 7

8 Boosting VRA Compression Rates: Improving CPU utilization and Compression Rates: Increasing the number of CPU cores from 1 to 2 on the protected and recovery VRAs will help lower the CPU utilization rate and improve the write I/O compression rates. If reverse replication is specified during Failover/Move, upgrading the peer site s VRAs CPU cores will also help with write compression rates. 8

9 Boosting VRA Compression Rates Instructions 1] Log into vsphere 2] Shut down the VRA where you want to upgrade the CPU core count. Right click the VRA > Power > Shut down guest 9

10 Boosting VRA Compression Rates 3] After the VRA has been shut down, Right click the VRA VM > Edit Settings. In the "Hardware" section, click on CPUs and increase the "Number of cores per socket" from 1 to 2 and click OK. 10

11 Boosting VRA Compression Rates 4] Power on the VRA Right click the VRA > Power > Power On 11

12 Boosting VRA Compression Rates 5] Right click the VRA > Edit Settings and verify that CPUs is reporting "2". 12

13 13 Log, logs and more logs There must be an easier way!

14 14 Agenda Log Collection: Then vs. Now What is Remote Log Collection? Security RLC Architecture Enabling Remote Log Collection Appendix 14

15 15 Then.. 15 Step ]1. Open a Support Case Step 2. Troubleshoot the issue with L1 Support Step 3. L1 Support collects logs directly while logged into the ZVM on a WebEx session OR you, the customer gathers the logs manually Alerts: VPGs: Sites: VRAs: vcd: Hypervisor: Hosts: Step 4. Logs are automatically\manually uploaded to one of Zerto s FTP server large bundles would sometimes fail. Step 6. (Optional) Repeat process if new logs are needed or logs did not upload correctly.

16 16 Log Collection used to require manual intervention with Zerto Support 16

17 17 Case information would have to be filled out manually which left room for human error. 17

18 18 Now.. In comes Remote Log Collection From the ZVM GUI, navigate to Menu > Remote Support *Administrator level privileges or User account with Manage Sites privileges are required Support takes it from there! 18

19 19 What is Remote Log Collection? Remote Log Collection provides Zerto Support the ability to gather logs from your ZVM environment without direct intervention Remote Log Collection will take YOU out of the sequence and help us to provide you faster turn around time on cases, with less dependence on YOU 19

20 20 Worried about security? Outbound Connection ONLY Connection automatically terminates once case closes Linked by case number via Salesforce API Limited Access Transfer logs using HTTP/HTTPS protocol from ZVM to a Zerto AWS S3 log Bucket Port 80 or

21 21 Networks

22 The Importance of Networks Production Site BC/DR Site vcente r VM VRA VM ZVM VRA WAN/VPN vcente r VM VRA VM ZVM VRA VM VM VM VM VM-Level Replication VM VM VM VM vdisk vdisk vdisk 22 Common Customer symptoms of a poorly performing network Elongated initial syncs Extended RPO s More bitmap sync ing than expected Network congestion VRA disconnects BC/DR down

23 Supported WAN Links LAN MPLS IP Link over Fiber Site-to-Site VPN Note - Zerto Virtual Replication does not support replicating through NAT translated devices via port forwarding. For replication to occur through NAT translated devices, all replication traffic must be within a VPN 23

24 VRA Network Performance Considerations VRA Default MTU = 1492 VRA Default Sockets = 8 Minimum 5Mbps dedicated bandwidth WAN Compression VPN/Firewall MPLS Network Filters Note - VRAs engage in PMTU discovery 24

25 zperf Test for effective available bandwidth between the VRAs and maximum TCP socket allocation zcperf Designed for a cloud scheme, which runs from the ZCC * Scripts are currently only available to Zerto support. iperf - Can be used to measure the available bandwidth between the ZVMs. Zerto WAN Sizing Tool VRA Network Support Tools Understand your write workload! 25

26 Miscellaneous & Useful Tools Notepad++ - Free, available and versatile. Bare Tail See logs live with keyword highlighting and tabs. Cmder Multi terminal console for Windows that includes Bash commands (grep, less, etc...) and Git integration. Wireshark Network analysis and trace tool. All of these tools save time and manual work, making it easier for us to focus on the problem. 26

27 27 Zerto PowerShell Cmdlets

28 Zerto PowerShell CMDlets - Getting Started In order to get started with Zerto s PowerShell CMDlets, you will first need to download the relevant Zerto PowerShell CMDlets installer. Running it will install the Zerto module on that VM, (Does not have to be the ZVM VM but has to have network access to it) After the installation, we need to import the Zerto Snap-In into PowerShell: powershell.exe -NoExit -Command Add-PSSnapIn Zerto.PS.Commands 28

29 Loading the CMDlets SnapIn Automatically Indeed, there is a way to load the Zerto SnapIn, each time you start PowerShell. This can be achieved using the following method: Add the SnapIn command to the powershell.exe path by adding the following line into the PowerShell shortcut (right-click, properties, shortcut): "powershell.exe -NoExit -Command Add-PSSnapIn Zerto.PS.Commands" - remember to add it after the \powershell.exe. Like so: powershell.exe {HERE} 29

30 30 Loading the CMDlets SnapIn Example

31 31 Zerto CMDlets Example We ll use ForceRemove-ProtectionGroup for this example: (Each step prompts for a user input) VirtualProtectionGroup: VPG name (Case sensitive!) ZVMIP: If you are running this from the ZVM, you can use localhost ZVMPort: Always 9080 Username: administrator (explanation on credentials slide) Password: password (explanation on credentials slide) Are you sure you want to perform this action? [Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): This identifier is the task ID sent to the ZVM essentially meaning it was successful

32 Zerto CMDlets One Liner The previous example showed an interactive PowerShell session where the user had to input answers/information for each step. You can run almost all CMDlets using a one line command, for example: ForceRemove-ProtectionGroup ZVMIP localhost ZVMPort 9080 Username administrator Password password VirtualProtectionGroup Test Confirm:$false 32

33 Zerto CMDlets Help The most important part of all, is that you can type: help cmdlet-name and get a full argument and flags review of that cmdlet. Example: help ForceRemove-ProtectionGroup This will allow you to understand what exact argument you should provide to the cmdlet. Not all are mandatory. 33

34 Zerto PowerShell CMDlets - Credentials The user given in Zerto s PowerShell CMDlets, is NOT the vcenter or ZVM user. These are separate credentials, stored in a text file at C:\Program Files\Zerto\Zerto Virtual Replication\users.txt In this file, there is the user administrator, and a hash of a string, to represent the password, which is by default password 34

35 Zerto PowerShell CMDlets - Credentials You can create different users and passwords, but passwords will always have to be hashed. There are many ways to hash a string ( as many as there are to un-hash it. In the ZVR installation folder: Users.txt the username and password combination, appears as so: administrator 5baa61e4c9b93f3f b6cf8331b7ee68fd8 (separated by tab [just click the Tab button on the keyboard]) Any other credentials, should be listed exactly the same, with the username first, Tab, and the password 35

36 36 Collaborate!

37 Thank You! Tal Hayut 37

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