Synthetic full & Data Domain Problems?

[biga888]

Hi, I am doing a new backup job, Incremental with Enable synthetic fulls.

The job work ok until the day it does the synthetic job. It seems to start, gives me a percentage but never seems to complete, and it freezes access to the Data domain device.
the only way I have been able to reset it it to reboot my Veeam server.

How long should a synthetic full job take?

[biga888]

ok, looks like it is a problem with it flooding the CIFS link. I changed the job to use NFS, and it seems to be happier. The job seems to be moving along now.

[Gostev]

Hi, what firmware version do you have on your DD box?

[tsightler]

A synthetic full job requires a huge amount of random I/O, I doubt that it is well suited for running directly on a Data Domain device.

We have a 1TB backup that produces around 70-120GB of incrementals a night, even with the new small block sizes because several of the servers see a high change rate. The synthetic fulls take about 6-8 hours on the weekends, but our backup storage is pretty fast, it keeps the storage running at 100-150MB/sec with several 1000 IOPS for that entire time. I don't own a DataDomain device, but my understanding is that they are not great IOP performers as that is not their goal.

I think the standing suggestion is generally to write the backups to a staging area and then copy them to the DataDomain.

[biga888]

We are running the latest firmware 4.9.

I have been thinking of the staging area idea, and I just need to plan how we are going to do that, create the scripts etc.
Thanks for the info!

The NFS connection works better as I was able to complete a synthetic full for the fist time.

[tsightler]

For some reason NFS always seems to work better with DataDomain, I've seen quite a number of users report that.