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143 Posts
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9206
Loss of XMS VM?
It sounds like deploying the XMS as a VM is the recommended approach. I presume it is a best practice to use VADP image-level backup software to backup the XMS on a regular basis (nightly?). Let's assume worst-case scenario, the XMS was not backed up, and for whatever reason the storage array it was running on suffers data loss and the XMS is destroyed. What is the procedure to build a new XMS and connect to an existing XtremIO Cluster? Is this a disruptive operation? Does the cluster get impacted in any way? Is there a need to have the encryption keys imported, or does the XMS "bypass" encryption?
chrismahon
18 Posts
1
March 17th, 2016 12:00
Hi Bill,
Good question! What I often tell customers is that if the XMS were lost or destroyed by accident, you can simply do the following to recover the XMS:
1. Deploy new XMS ova VM with equal or greater code of the cluster
2. Upload code image (upgrade-to-4.0.2-80.tar as an example) to the XMS using the xmsupload account and WinSCP
3. Perform XMS install only (from xinstall account in the CLI on the XMS) targeting to code file you uploaded
4. Perform XMS recovery of the cluster
Some of these steps can be a bit of a task if you are unfamiliar with the xinstall (easy install) CLI. EMC Support can assist if this is ever needed.
These tasks are non-disruptive to host I/O on the array. The loss of the XMS will not cause the array to be down. As far as the image-level backup of the VM, I have seen instances where a the backup software used will cause a hang in the XMS requiring a reboot of the XMS. Just be aware of that! Finally, there should be no concerns to the cluster encryption when recovering a XMS as encryption is handled at the cluster level (SED of the SSDs) rather than the XMS level.
Thanks,
Chris Mahon, VCP, EMCIE, EMCCA
EMC Corporation | Delivery Specialist II
boyler05
143 Posts
0
March 17th, 2016 14:00
Thanks, that is great to hear! Does EMC have an official "best practice" on backing up the virtual XMS?
Bill
Kumar_A
727 Posts
1
March 17th, 2016 16:00
We don’t support backing up the vXMS using snapshots or any other backup software (due to the fact it would mean reverting to an earlier config that would be out of sync with the array).
As Chris mentioned earlier, the XMS data is stored on the array which can easily be recoved if needed.
scotthoward
64 Posts
1
March 17th, 2016 17:00
Best practice is to NOT backup (or snapshot) the vXMS.
Doing so means that it reverts to an older version when you restore it, which leave you with the XMS and the array(s) it's managing being out of sync.
The only valid way today to "restore" the XMS is to deploy a new XMS, as Chris has mentioned.
The reason the restore works is that the XMS actually backs up its config to the storage controllers at regular (frequent) intervals, so when you do the XMS recovery it's bringing back a current version of the XMS and array config.
We're working on options for external backups, simply because some people like to have them, but they really aren't needed at least as far as configuration/etc goes. (Performance history is the exception, and today there's no way to back that up)
boyler05
143 Posts
0
March 18th, 2016 06:00
Great info, thanks so much to everyone for sharing!!
hex666
18 Posts
0
April 12th, 2016 14:00
one question that i have is where do i download the code image to bring up to proper 4.0.2.80 version.
thanks
echolaughmk
522 Posts
0
April 12th, 2016 14:00
You can find that on support.emc.com under the XtremIO product or just by searching. Note - access to download it depends on the proper credentials.
-Keith
hex666
18 Posts
0
April 12th, 2016 15:00
Keith,
i must not have the proper access as i have searched and i do not have that in my search results.
thanks for your reply
hex666
18 Posts
0
April 14th, 2016 14:00
Avi,
yes i can reach that page
Kumar_A
727 Posts
0
April 14th, 2016 14:00
Are you able to access the following link: https://support.emc.com/downloads/34156_XtremIO-HW-Gen2-400GB ?
vogie563
14 Posts
0
April 15th, 2016 11:00
Can confirm the backup of the vXMS is a bad idea. When we upgraded from a flavor of version 3 to 4 the VMware snapshots that were occurring at the time on the vXMS caused it to crash. We were not aware at the time that the XMS data was saved back to the array as the backup. We have since stopped the snapshots.
Marcin_Wolny
3 Posts
0
July 16th, 2017 04:00
Yes snapshot of this VM can cause a problems. For sure quiescening must be disabled.
vogie563
14 Posts
0
July 17th, 2017 05:00
In a newer version of 4 code they did add a export/backup feature to the XMS. It's in the GUI under Inventory, XMS, Export or you can use "backup-xms" CLI. In a recovery of the XMS I'm going to assume you should probably use what's been saved to the array, but this at least get's your config off the XMS/Array for extra CYA. In previous versions not having a good XMS backup did bite us when rebuilding it since items like tags were XMS side and not on the data saved back to the array. (I believe tags may be part of that array backup now, not 100% though). That did hurt us just for the fact our tags, etc. were called by our snapshot/backup scripts so rebuilding that was not fun when we had a XMS failure.