Direct SAN on one, network on others

[merc123]

I have Veeam installed on a Server 2008 R2 VM with a RDM mapped to it from the SAN. It's NTFS formatted and attached as the V: drive on the server.

From day one with all of my jobs it has always given warnings about "unable to establish direct connection shared storage" and is fails over to network mode. One of the VM's in the job that is powered off does not give this warning.

Well recently I had to separate out one of my VM's (Veeam) into it's own job and I noticed that it does not give this warning and appears to use direct SAN access as the target and network load is 0% and proxy is only 15%. On the other jobs with network mode the network is ~40%, target is 1% and proxy is 56% or more.

I'm wondering what's different between the jobs that allows one to go with direct access and the others not?

Looking at the jobs the only difference is on the one that does network mode I have quiescence enabled but on the Veeam VM I do not. Also I have the Veeam VM added as the VM to backup whereas on the other job I have the actually host with exclusions set up for the other VM's.

Whatcha think? Thanks.

[Vitaliy S.]

From day one with all of my jobs it has always given warnings about "unable to establish direct connection shared storage" and is fails over to network mode.

Have you mounted your SAN LUNs to the backup proxy server to make your jobs use direct SAN mode as it is described in our sticky F.A.Q. topic?

[merc123]

I did but I could not see the LUN in the Backup repository. I'm thinking this may be where my flaw was now that I looked at the backup proxy. I'm guessing that you don't have to specify the repository for direct SAN access?

[Gostev]

I am totally confused. So, you are talking about backup repository now, and not backup proxy?
If that is the case, do you see this LUN as a drive in the Windows Explorer on your backup repository server?

Don't really understand what you are asking here.

[merc123]

1. Backup Proxy is set to "Direct SAN Access" transport mode and "failover to network mode if primary transport modes fail or are unavailable" is checked.
2. Backup Repository currently has the V: drive set as the path to back up to. The V: drive is a SAN LUN that is being used as a raw device mapping (RDM), NTFS volume and can be seen in WIndows Explorer.

When I followed the directions in the sticky FAQ to try direct SAN access I could not get it to work. I created the SAN LUN, presented it to the host (ESXi), and created a VMFS datastore out of it. I presented that datastore to the backp repository server and I could see it in disk management as an uninitialized drive. At this point I tried to add the uninitialized drive to the backup server as a Backup Repository location but it could not see it without assigning a drive letter.

So, what I'm wondering is if I do not need to add the VMFS datastore to the backup repositories, that the backup server will automatically know to back it up to the VMFS datastore.

[Gostev]

Thanks for the explanation. Backup repositories is WHERE you are backing up, not FROM WHERE. For backup repository, you should specify a local drive, or NTFS LUN (must be mounted to backup repository server, and assigned letter before you can pick it as destination). However, you should NEVER make VMFS LUN a backup repository, as mounting VMFS LUN in Windows will just corrupt all data there.

As long as VMFS LUN holding the VMs you want to backup is mounted to the backup proxy and can be seen under Windows Disk Management (no need to initialize or assign drive letter), there is nothing else you need to do to enable direct SAN backups. The backup engine will figure out this is the LUN it needs to read from to backup certain VMs on its own.

Hope this answers your question, if not, let me know what else is not clear?

[merc123]

I'm just now revisiting this, hopefully a little more experienced. I did also go back and check the FAQ and I see this:

Q: I have FC SAN and running Veeam Backup in a VM. Can I use direct SAN access mode via NPIV?
A: No. VMware supports NPIV for RDM disks in physical mode only. Veeam Backup does not support backing up pRDM disks, because VMware does not support snapshotting such disks. You can, however leverage NPIV to mount LUN to VM as pRDM disk, format it with NTFS and use as target for your backups, thus making you backups completely LAN-free. This makes it perfect backup target!

I'm running Veeam in a VM. Since my backup repository is a RDM and is already on the SAN, it would seem that it is already a direct SAN connection since it's saving straight to the RDM which is on the SAN.

[foggy]

You can call it "direct" in some sense, however it is not the same as Direct SAN transport mode used to read data from the source storage. The FAQ question is about READING VM data from source. What you have set up, is LAN free WRITING of backup data to the target storage.