Direct Storage Access vs Virtual Appliance

[StuartW_D]

Hi,

I have found one or two forum posts about this topic and what I have seen most people are saying there is a performance improvement since its going over the SAN fabric rather than your network infrastructure. I wanted to see if anyone else has some stories about the improvement they experiences between these two methodologies.

Another point that I am very interested in is that in the documentation is mentions that Virtual Appliance is responsible for a lot of virtual machines requiring consolidations. I was curious how this could be the case, since I thought that Direct Storage still uses snapshots too, so why would one method have a higher issue than the other. I wanted to know if anyone has had experience on this side of things. Have you seen a decrease in snapshot related issue using Directo Storage Access over Virtual Appliance.

Why I am really interesting in this is we occasionally have issues with the Snapshot/Consolidation process, either causing phantom snapshots and down the line we encounter stuns on the VMs etc, which is a big issue for us. If I can reduce this even more, I would really be interested.

Kind Regards,
Stuart Wepener

[PTide]

Hi,

the documentation is mentions that Virtual Appliance is responsible for a lot of virtual machines requiring consolidations.

Not sure what you mean, could you provide the quote please?

Why I am really interesting in this is we occasionally have issues with the Snapshot/Consolidation process, either causing phantom snapshots and down the line we encounter stuns on the VMs etc, which is a big issue for us. If I can reduce this even more, I would really be interested.

Snapshot hunter is supposed to deal with phantom (orphaned) snapshots. If orphaned snapshots appear frequently and cause VMs to stun the I'd suggest you to contact our support team.

Thanks

[StuartW_D]

Hi PTide


https://www.veeam.com/blog/vmware-backu ... ation.html

Under the "The Bad & Ugly" of HotAdd

"#1 source of stuck (Consolidation Needed) and hidden snapshots."

[DGrinev]

Hi Stuart,

Transport mode shouldn't affect the snapshot consolidation time (shouldn't be a dramatic difference).
Please be aware that snapshot consolidation (time and reliability) depends on the vSphere version.
From version 6.0 there have been large improvements in regards to snapshot commit.

However, failed detachment of the VM disks during Hotadd mode could be the reason of phantom snapshots.
That's why i would recommend to investigate every occasion with our technical support team.

Thanks!

[StuartW_D]

Thanks DGrinev, I will definitely pursue the phantom snapshots more with the support team, for now however I still want to get feedback from general persons about their experience between the two modes. Are there fewer phantom snapshots and consolidation requirements using the direct storage mode?

[Gostev]

Yes, stuck snapshots are less likely (at least this was the case when it was a real problem with VMware, these days they are pretty rare).

[StuartW_D]

Thanks Gostev,

So far its highlighted that we should not be getting consolidation requests and phantom snapshots nearly as often as we should be. I will be looking into it, I am also very keep to look into Direct Storage Access as we may be able to get a bit more juice out of our backups with the added benefit of more seldom snapshot issues.

[Delo123]

Hi Stuart,

we swtitched from hot-add to dirrect SAN years ago and have been happy ever after. There were occasional issues with stuck snapshots in hot-add mode but we could almost everytime pinpoint that to internal vsphere / vcenter issues. But logically direct-san not only offloads your network, it also offloads your production hbas as data doesn not have to travel over them when backuping giving you a better experiance on your production hosts. So if you are able to do direct SAN access, personally i would recommend this very. Ps. we only offer the luns to the backup machines as "read only", just in case We only have one additional lun which is R/W mounted in case we want to do a direct san full restore.

[Frosty]

We're still using HotAdd and are quite happy with it (has been in place for 5+ years now). We don't have any issues with unwanted snapshots being left behind. Our environment is Dell R710 hosts, Dell MD3200 Direct Attached Storage and vSphere v5.5 (recently updated from v5.1 where it was also stable).

[Andreas Neufert]

Hi,
if you want to know more about this topic, please read our best practices guide starting from this chappter.

https://bp.veeam.expert/resource_planni ... modes.html

[StuartW_D]

Sorry for the very late reply. Thanks to everyone who added their thoughts.

I have opened a case with support to see if I can sort out the current issue with Hot Add. Also when I have a gap, I am going to test out the DS Access mode, compare the results and see whether it fits our future plans for our infrastructure.