Speed of backups

[bokinns]

Hi All,

I have installed Veeam backup 4.0 in a trial mode with vSphere 4.

I have a job making 17-VM backup normally but there are 3 VMs that are good backup but at a very low Processing rate.

The normal Processing rate is between 200MB/s to 1GB/s but processing rate of these VM is only 40MB/s with this error message:"Enabling changed block tracking... Changed block tracking cannot be enabled: one or more snapshots present."

what is the problem?

Thank you.

[Gostev]

Hello, judging on the error you have existing snapshots on these VMs.

Changed block tracking cannot be enabled if VM has at least one snapshot present. You should remove all snapshots from these VMs, and run the job again. Veeam Backup should then be able to enable and leverage changed block tracking for these VMs.

Note that you can continue using snapshots without any limitations after changed block tracking has been enabled on VM by Veeam Backup.

[bokinns]

Hi Gostev,

Thank you, I removed snapshots and backups has worked perfectly and very fast.

[bokinns]

HI!,
Now I don´t have this error but, there are som way to have a snapshot and backup go faster?

[Gostev]

What is your environment (ESX version and storage), backup mode, where are you backing up to, and what speed are you getting for the incremetal backups?

[bokinns]

We are using vCenter 4.0 with RAID10 SAN, the backup mode is SAN/NBD with changed block tracking, we are doing the back up in a external USB HDD loceted in datacenter.

But what worries me is that average processing rate servers is 400MB/S and this server has a prossesing rate about 20MB/S
This is a SQL server but backup goes at 4 am and at this time the activity of server is around 0, and in this server I don't have snaphots.

[Gostev]

Please check the VRB file sizes, are they big for this VM?
Also please make sure if the session log does not say that the job failed over to NBD.

Also we would probably need logs to see what operation exactly takes so long, may be it is VSS freeze for example.

[tsightler]

We are using vCenter 4.0 with RAID10 SAN, the backup mode is SAN/NBD with changed block tracking, we are doing the back up in a external USB HDD loceted in datacenter.

But what worries me is that average processing rate servers is 400MB/S and this server has a prossesing rate about 20MB/S
This is a SQL server but backup goes at 4 am and at this time the activity of server is around 0, and in this server I don't have snaphots.

How big is this SQL server? What is it's change rate (in other words, does it have a relatively high change rate). We have three systems which are slow to backup even with Veeam 4, ESX 4 with block change tracking, at least compared to our other servers. The servers are our Exchange 2003 server and two Microsoft SQL servers (one SQL 2000, the other SQL 2005). What do these all have in common? They both have fairly high transactional workloads which change a lot of blocks all over the filesystem and thus generate relatively large VBR files (10-30% of the full backup). I think the main "problem" with this workload is the relatively large block size that Veeam uses cause a very high percentage of blocks being "changed", and the fact that Veeam has to read the old data from the VBK, write the data to the VBR, and then write the new block to the VBK. That's a lot of I/O on the target storage.

We do have one SQL 2005 server that doesn't see this problem, but it's a relatively small (80GB) and quiet server that sees very little change during a day. Let us know what size VBR's you seeing and it will help determine if this is the issue you are seeing.

[bokinns]

Thanks for all,
I have said it is normal that the server takes so long because it makes backups more.
all servers are doing very fast backups from the moment I remove the snapshots and I'm satisfied.