Best practice to backup pRDM with Veeam

[Archvile]

Hi !

We have VMs with physical mode RDMs (Veeam 4.1, ESX 4.0, IBM DS4700 array).
We don't want to use IBM's FlashCopy/VolumeCopy (due to its price); we want
to backup storage array with Veeam. Can we perform "LUN-level" or "block-level"
backups with Veeam ? What would you recommend as best practice for centralized
backup of VMs with physical RDMs as well as standalone LUNs ? Or partition-level
backup is the only option ?

Thanks !

[tsightler]

Physical RDM's don't support snapshots, so they are a "no-go" with Veeam. Veeam is a VM level backup product so it depends on VMware snapshots to work.

[Alexey D.]

Hello Alexander,

Tom is right. Maybe, migrating to virtual RDMs could be an option for you?

[Archvile]

Thanks for replies ! Now I've got the point about snapshot

I was confused about veeam's ability to copy files directly from ESX/linux - my logic was
"if it can access linux FS, maybe it can access /dev/sdb, umount it from pRDM file and dd
it while VMs are freezed and there is no I/O"

Hello Alexander,
Tom is right. Maybe, migrating to virtual RDMs could be an option for you?

Probably, not. As I suppose, virtual RDM does not support SPC-3 (we need to use persistent reservations with Win2008 Failover Cluster).

[Gostev]

"if it can access linux FS, maybe it can access /dev/sdb, umount it from pRDM file and dd
it while VMs are freezed and there is no I/O"

VM stays frozen for only about one second (this is when the snapshot is created), this time is of course not enough to copy the whole disk

[Daveyd]

[merged]

I am in the process of building new 2008 R2 VMs on an ESXi 5.0 cluster that will have their OS drive on a vmfs datastore and their Data drives mapped via a physical RDM. We want to replicate the VMs to another ESXi 5 cluster but only want to replicate the VM and the OS drive and not the phyiscal RDM. Is this possible with Veeam replication with an exclusion?

[Vitaliy S.]

Hi Dave,

While you can certainly exclude disks from actual backup, VMware does not provide ways of excluding disk from snapshots, so it will not be possible to process this VM at all unless you decide to switch to vRDM disk.

Thanks!

[Daveyd]

Hi Dave,

While you can certainly exclude disks from actual backup, VMware does not provide ways of excluding disk from snapshots, so it will not be possible to process this VM at all unless you decide to switch to vRDM disk.

Thanks!

So, if I were to mount the RDM as virtual, I would then be able to exclude the vRDM from being replicated, correct?

We currently use Bridgehead software to do ISB/IDR clones, (fracture/copy) of the LUNs that are physical servers are on. We want to move theses LUNs to the new VMs as their Data drives and replicate the VM, exclusing theses drives as long as mounting the drives in virtual mode does not break any one the SAN commands that the Bridgehead software uses to do its clones

[Daveyd]

Looks like our vendor only support physical mode RDMs, which is a bummer. Seems like I am SOL with trying to replicate a VM and exclude a physical RDM

[Vitaliy S.]

So, if I were to mount the RDM as virtual, I would then be able to exclude the vRDM from being replicated, correct?

Yes, any supported disk type can be excluded from VM backup/replica job.

[Daveyd]

Yes, any supported disk type can be excluded from VM backup/replica job.

OK, I just did this test. I created a 2008 R2 on Cluster1/SAN1/VMFS Datastore1 with 1 vmdk for the OS drive. I created a LUN on SAN1 and presented it to Cluster1. I then added then new LUn as an RDM to the VM and formatted it with NTFS.

I created a Veeam replication job with the source VM being the one I created above. The destination was Cluster2/SAN2/VMFS Datastore2. I chose all the default replication job settings. I then ran the replication job. The job ran sucessfully and the _replica VM was created on Cluster2. I shout down the VM with the RDM attached and did a failover to the replica. The failover completed sucessfully and I was able to boot up the replica. The replica booted with no errors. I looked in the replica's Storage manger and the only thing that was there was the C: drive...no RDM (to be expected). I did a permanent failover with no issues.

It seems like my goal of replicating an entire VM (just VM and OS drive) when that VM has a physical RDM attached suceeded...or am I missing something?

[Vitaliy S.]

I have no other explanation except that sounds like you're still using RDM in virtual mode

[Daveyd]

Here is the VM I am replicating...When I try and take a snapshot through vCenter, I get "Cannot take a memory snapshot, since the virtual machine is configured with independent disks". If I uncheck "Snapshot the virtual machine's memory" it allows me to take the snapshot. The Veeam replication job does not have Enable VMware Tools quiescence checked. It replicates fine, just does not have the RDM attached, which is to be expected. Am I looking at this or doing something wrong to make it "work"?

[Daveyd]

Looking at the Replicatin log on the VM, it does say "Disk:[OS01_LUN3003_R5]TestVM/TestVM_1.vmdk has been skipped du to unsupported type (raw device mapping in physical compatibility mode). So it looks like it is skipping the RDM because it's in physical mode and replicating everything else...which in my situation is a good thing since I just wanted to replicate the VM with just it's OS drive which is not an RDM.

[foggy]

Actually, unsupported disks are automatically excluded from backup starting from v5 so you do not even need to exclude them manually. I believe this is possible right because Veeam B&R takes snapshots without VM memory.

[Daveyd]

I think I just proved that with my testing as well

This will work perfectly for us since the LUN that the VM's "data" drive is on HAS to be a physical mode RDM. That particular LUN is actually being backed up using other software using LUN clones. So, the thinking is, replicating the VM with the RDM from our Production SAN to our DR SAN. When we do a failover to DR, the VM with the RDM will failover but without the RDM. We will then have to attach the backed up Clone LUN to the VM as an RDM which is now residing on the DR SAN.

Since the vendor only supports physical mode RDMs, this seems like the only thing we can do for Replication to work.

[SAMbI4]

Hello community, i have big question.
I have File server (dase on Win 2012R2), i have iscsi LUN (30 Tb) mapped on esxi, and mount DRM disk on VM.
But veeam work with only vRDM disk, question is, how i make backup this disk?

[DGrinev]

Hi and welcome to the community!

You can't make a backup of the pRDM with Veeam B&R as you said. You might consider switching to vRDM or try to use Veeam agent for windows.
Please review this thread for additional information. Thanks!