More diskspace in the datastore of the hypervisor where the VM resides.

Or, if you have more than one datastore at your hypervisor, move the VM to a datastore with more free diskspace.

Your alternative to the solutions @JMeixner has provided is redirecting the snapshot file to an alternative datastore.

If you do this though, please ensure that you don’t overwhelm the datastore if you have multiple VMs being processed all committing their IO to this datastore. You’ll still need to have size & performance considered when picking a valid target.

Information on how to configure this is here:

https://kb.vmware.com/s/article/1002929

What about an agent based backup? should I create additional storage?

Agent based backup uses VSS, so you just need the free space on the disk.

Hi, I think @JMeixner and @MicoolPaul gave you the best answer to your question.

Agent based is possible, but if you are backing up VMS, the best way to do it is not mixing techs, agent backup is used to backup physical machines at most.

You can add more storage, and / or move your snapshots store to a non full datastore to not get jobs failure.

Cheers.

Hi @Anandu  You can administer the various alarms on the production datastores via “General Options\option” and have a mail\ ticket sent to you.

Hey guys,

Now we all know the backup workflow for Veeam. During backup workflow Veeam instructs the client to create a snapshot. But I have seen in customer environments where backup jobs have resulted in failure or warnings where it says not enough space to create snapshot. What is the recommended solution for this outcome?

Hi @Anandu  You can administer the various alarms on the production datastores via “General Options\option” and have a mail\ ticket sent to you.

 

Exactly this. Veeam need 10% of free datastore space as vmware reccomandations.

You can uncheck these options, but keep in mind:

with more of 5% free but under 10% it works BUT with a probability of error.

Under 5% free backup probability of error on processing is high.

Mhh, the percentages depend on the size of the datastores and the size if your VMs and snapshots. If you have a 100TB datastore 3% free space is more that 10% free space on a 20TB datastore….

Yes, you’re right. This is what I see from my experience (and surely mine is less than yours guys ).
PS. You replied before I finished to re-edit my reply 

Just apart of the discussion, I don't like touching veeam`s recommended percentages, its enough to be safe, and avoid “easy” problems like datastore space during snapshots for backups.

I usually like having free space, most of the time, I measure it like, what about if I need to restore an entire vm?

I usual keep free the amount of space of my larger vm in that datastore. (in a small environment)

for big machines / deployments, we usually leave 20% off  of a datastore, so we don't get warnings or problems with snapshots and incrementals, and we have a “slow” or “old” datastore to restore in case of needed.

Just to tell a little Storie, and share a bit with you guys.

have a great weekend you all!

Absolutely, and I don’t wanna think about a vm that need to consolidate a snapshot with no free space 

This is why I hate percentage based alarms.  In my old environment, we ended up having alarms that were percentate OR > 100GB or whatever.  Had to be a twofer.

Been there.  Your options then are to either increase the datastore or move something off.