VCB is slow on FC San

[DefSol]

We have ESX server ver 3.5.0, 110268 and when we run VCB to create full back ups it is so slow. The process has Symantec to kick of the VCB command (through a pre job execute). When looking at the VCB log it takes 45 mins (rough calc by taking time on log) to copy 135G - our db vm and is one of our smaller VM's. I have no idea as to why it takes this long, but think it should be a lot faster???

I don't think it's a BE issue as the error relates to the pre batch job taking too long - ie VCB is to slow...

We have an 3 IBM x3650 servers connect to an IBM San with 4G f/c. the intended process was to back up the VM's to disk and then off to tape (via BE) - but now the whole process runs 26+ hrs.

Any ideas greatly appreciated.

Reuben

[Craig_Baltzer]

Are you doing a "full VM" backup (i.e. creating a copy of the VMDK and other VM files) with VCB? Is the copy also being created on the SAN or on local storage of the backup server? I've had performance problems with VCB when I was creating a full copy to local disk on my backup server...

[DefSol]

Hey Craig,

we have 4 luns on the san - L1 for junk & temp, L2&L3 hold data stores for the ESX servers & the last lun is assigned to the backup server and the whole lun is mounted as a logical drive.

The process has us backing up full vms from L2 & L3 to L4. So BE calls VCB to snap and copy VM's from L2 & L3 to L4. It is this process that seems to be the bottle neck.

Regards

Reuben

[Craig_Baltzer]

Hi Reuben. If you do a "LUN to LUN" copy on the SAN, what sort of throughput do you see there? To get a rough idea maybe try moving the storage for a VM from L2 to L3 using the VI client and timing how long it takes. Good to have a baseline to see how much slower VCB is than just a regular copy.

What kind of SAN?

[DefSol]

Hey Craig,

I will look to do the copy tomorrow. On the San side with have an IBM DS3400. The Server, FC Switch and SAN were installed 3 months ago - so all pretty new gear.

Regards

Reuben

[abjuca]

so what is better ? use a LUN for temp or use a local disk ?!

I tought that temp in a LUN was better, isnt that ?!

what about your tests ?!

see ya

[dconvery]

The best throughput you will get for the VM copy to the holding tank is about 1GB per minute. I have installed VCB for dozens of customers. That is the best you will get, SAN, local SCSI, SATA. Just make the disk SAN based SATA or local SCSI. Stay away from iSCSI unless you are running 10GbE.

I always thought it was a limitation with VCB to keep from saturating the channel, but it turns out it is a limitation in the winders cmd.exe copy method. If you do a GUI drag and drop, it flies....Go figure.

Dave

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