Best method of backing up to disk then tape

[agile83]

Hi guys,

We are currently speccing up a new VMware environment and Im not 100% sure about how the backup part works and therefore the best way to design it.

We have a SAN and two ESXi hosts connected via SAS cables. We then have a management server which contains Veeam and Vsphere Vcenter. This management server has a SAS cable going from itself into the SAN. We want to back up the VMs to disk first and then off to tape later on during the next day.

My question is, should we have our 2 x mirrored 3TB disks placed into the SAN and presented to the management server as just a normal Windows drive? If i do this does that mean Veeam will be backing up via the SAS cable or would it be via the network cable? My thoughts were that the 2 x mirrored 3TB disks could go physically into the management server where Veeam already is and this might be better, but would this also work by backing up via SAS?

Im just confused slightly over what architure Veeam uses and therefore how best to set it up to ensure fast data transfer. Hope you can clear this up for me, cheers

[Shestakov]

Hi,
So the best way is to set up Direct SAN transport mode.
Usually connections via FC or iSCSI are used, but it also might be possible to connect via SAS. Please check this topic.
Thanks!

[agile83]

Thanks for the reply - from reading the link you sent it appears it would be possible, the SAN will be an IBM Storwize and Veeam would be installed on a physical server directly connected to the Storwize via SAS.

Would it be better for me to back up using Veeam to disks within the SAN or should I add the disks to the physical management server instead? Is there a best practice which dictates which method makes more sense?

I've seen a customer present some disks from their SAN solution to the Windows Veeam server but with the scenario I am going for with the Storwize I'd prefer the disks to be located inside the management server.

Can you advise? Cheers

[Shestakov]

Would it be better for me to back up using Veeam to disks within the SAN or should I add the disks to the physical management server instead? Is there a best practice which dictates which method makes more sense?

Direct SAN mode is considered as best practice and usually shows the best backup performance. I would suggest to try it out and check if it works fine for you.
Thanks!

[agile83]

Thanks Shestakov, im now considering trying this out. Can you explain how data is transferred from the Virtual machine LUNs in the main RAID array on the SAN to ( for example) 2 mirrored 3TB disks also in the SAN? In the scenario i mentioned would data travel up to the management server via SAS and then back down to the SAN via SAS? Cheers

[Shestakov]

VBR leverages VMware VADP to transport VM data directly from and to FC and iSCSI storage over the SAN. VM data travels over the SAN, bypassing ESX(i) hosts and the LAN.

Data Retrieval in Direct SAN Access Mode is described in the user guide:
1. The backup proxy sends a request to the ESX(i) host to locate the necessary VM on the datastore.
2. The ESX(i) host locates the VM.
3. The ESX(i) host retrieves metadata about the layout of VM disks on the storage (physical addresses of data blocks).
4. The ESX(i) host sends metadata to the backup proxy.
5. The backup proxy uses metadata to copy VM data blocks directly from the storage via the SAN.
6. The backup proxy processes copied data blocks and sends them to the target.

Note that backup proxy using the Direct SAN Access transport mode must have a direct access to the production storage via a hardware or software HBA. If a direct SAN connection is not configured or not available when a job or task starts, the job or task will fail.

[foggy]

I would not recommend putting the disks where you're going to store backups in the same SAN, where you production datastores are - to avoid losing everything in case of SAN failure. I'd better place them into management server itself, thus you'll also avoid data transfer back to the SAN via network.

[agile83]

Hi Foggy,

I plan to back up using Veeam during the night and then back that off to LTO6 during the day to achieve my offsite backup. I'd be keen to employ Direct SAN access and the benefits that brings, however does data transfer back to the san over ethernet instead of the SAS cable that it presumably came up?

I was keen to know the data transfer paths and thats why i asked the question further up. Can you confirm?

[foggy]

It comes down to how the volume is presented to the management server.

[agile83]

It is presented via SAS. So would it use the SAS cable and not the ethernet cable, correct?

[foggy]

Then I guess it would use SAS. You can check by simply copying a file from the management server to the SAN.