I am investigating some performance issues we are having backing up to tape using BE 2010 R3.
THe way our process works is we do a B2D2T we have a backup server where we have Veeam installed which we use to backup to disk. We then use BE 2010 R3 to backup the veeam file created (one large 1tb .vbk file). This veeam file is a file which Veeam creates when creating backups of our VMs in VMware.
This file has already been compressed within Veeam. We then backup this 1 file to tape onto our IBM TS3200 tape library directly connected via 6GB SAS on the backup server. We recently upgraded the unit in here to LT0-5. We were using LT0-4 before but the performance we are getting is the same as LT0-4.
Firmware upgrades on the tape library unit, server have all been done. BE is fully patched up on the server. Its running Windows 2008 32-bit with 4gb ram.
We have tried numerous tests with buffer settings but still the same performance. We have turned encryption off and compression within BE only off.
I am running out of ideas and am now thinking could it be that because this veeam file is already compressed. Is symantec just slowing down because its already compressed?
Is there any advice on backing to tape changing settings within BE? I have tried numerous settings within BE. Currently the device is set as the following:
Firstly I do not think there was a huge improvement in maximum speed from LTO-4 to LTO-5 (around 15% iirc) - the new technology was mainy around additional capacity.
Secondly, if the time taken / rate of transfer is totally unchanged then it is more likely that the bottleneck is something to do with the server processing, and compression would be the most likely culprit.
You chould have enough capacity on the tape without compression so why not give it a go?