Categories: XenServer, FAQs, Alike v3

Introduction

When XenServer runs out of storage space on an SR (Storage Repository), it can cause various errors in Alike.

Some common errors include the following:

“XenServer failed to create snapshot on VM . Xen error: The specified storage repository has insufficient space”

“SR_BACKEND_FAILURE_44 insufficient space”

“Failed to provision new VM. The specified storage repository has insufficient space”

These can occur in backup, replication or restore jobs, but all of these error message point to the same problem: there’s not enough space free in the Xen SR to continue.

When you encounter any of these error messages, it’s a good idea to confirm the problem by manually taking a snapshot of the afflicted VM in XenCenter. If this fails with a similar error, then you will need to find a way to free space on that SR. Typically this can be done by deleting any unnecessary snapshots, removing unwanted virtual disks, etc.

If you want to learn more about the post-snapshot deletion process, potential bottlenecks in coalesce, and how to identify and address coalesce related issues in a XenServer environment. you may want to refer to the following Citrix KB article.

An additional Citrix resource that can help explain how XenServer uses snapshots, please refer to the Citrix White Paper CTX122978, Understanding Snapshots.

Final Notes

Finally, it is worth mentioning that Alike’s Q-Hybrid technology does not utilize XenServer snapshots, so it protects your VMs, even if you are having storage space issues in your Xen SR. Refer to the KB article, Configuring Q-Hybrid Jobs for more information on Alike’s Q-hybrid jobs, and how to use them.