Snapshot Creation

[matthieu178]

Hi,
I'm currently using Veeam Backup And Replication 5.0.2, and I need some help after a machine crash.

If I understood correctly, veeam creates a snapshot and makes a backup of it.
But does it compress the snapshot or must there be at least the size of the virtual machine on the disk in order to back it up with veeam?
Thank you very much for your help to come

[foggy]

Hi, Matthieu.

I think here is a misunderstanding of the whole snapshot technology. When snapshot is created, it has a zero size. As VM starts to write to this brand new snapshot vmdk file, it grows in size but not very quickly (depending on the VM's activity) and of course cannot grow larger than the original vmdk (which is left intact allowing third-party apps such as Veeam to safely copy it).

So you obviously need a free space on your storage to save snapshot but typically much smaller in size than the actual VM. And no, snapshot is not compressed during backup, but the data that is backed up by Veeam is compressed (unless compression is disabled in the job settings).

Thanks,
Alexander.

[matthieu178]

Thanks for the answer.
It's just that I don't get why my machine crased and that the datastore was full...

[Gostev]

It looks like your datastore does not have enough free space to accommodate the required snapshot grow while the backup is running.

[brunob]

Hello,

we have the same Problem. (Using Veeam 5.02)

can we set an parameter in VMware or Veeam that if the Volume is full, VMware is stopping the snapshot or send an eMail
without crashing the VM?

sorry about the Text, my english is not so good

Best regards
Stefan
Germany

[Vitaliy S.]

Hello Stefan,

Have you considered using Veeam Monitor to raise an alarm with a post-alarm action in order to avoid situations like yours? Moreover we've got snapshot specific alarms that you can also use.

Here is the Veeam Monitor homepage for further reading:
http://www.veeam.com/vmware-esx-monitoring.html?ad=menu

Thanks.

[sanbarrow]

can we set an parameter in VMware or Veeam that if the Volume is full, VMware is stopping the snapshot ...

Yes - you can set
snapshot.minFreeSpace = "55000000000" (value in bytes)

if there is less free space than configured no new snapshots will be created by VMware.
Note that you have to set this per VM by manually editing the vmx-file

[Gostev]

No need to bother setting this for each VM... Veeam has the same setting, except it is global and hardcoded at 2 GB I believe (configurable via the registry setting). The job will simply not create a snapshot if remaining free disk space on datastore is less than 2 GB.

There is also automatic notification configurable via Tools > Options > Notification, with default being 10 GB. This will make the job to log warning in the session, but still proceed normally.