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Understanding VSS better

BillClark22
Level 4

Using Backup Exec 2014 V-Ray Edition to protect our VMware environment that has 6 ESXi v5.1 hosts.  I have a question regarding the whole VSS process.  I understand that there are two possible VSS Providers in our environment, the one included with VMware Tools and the one included with the Remote Agent for Backup Exec.  Just to clarify, regardless of which VSS Provider I use, they both talk to the Microsoft Volume Shadow Copy Service to actually do the snapshot of the virtual server, correct?  If so, is there an alternative method to create full virtual machine backups that don't rely on the Microsoft VSS?  Something that VMware and/or Backup Exec can do completely outside of the guest Windows environment?  Thanks.

 

Bill

8 REPLIES 8

CraigV
Moderator
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Hi,

 

Yes, they both talk to the Microsoft VSCS. There isn't any other way to do this other than on a storage level, but BE can't see storage snapshots like Veeam can for instance.

THanks!

CraigV
Moderator
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Read below:

https://support.symantec.com/en_US/article.TECH173983.html

BillClark22
Level 4

That's what I was thinking was the case, just wasn't 100% sure.  Any idea or word if BE is looking to enable storage level snapshots like Veeam does?  We had phased out a small implementation of Veeam in favor of updating and upgrading our Backup Exec implementation to try and keep things simple with one product for all of our backup scenarios.

This has become an issue with us because of our setup of using EMC Recoverpoint in conjunction with VMware SRM.  When BE jobs create whole virtual server backups, it causes a huge increase in replication data that takes a long time to process and synchronize.

CraigV
Moderator
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No, Symantec won't publish a roadmap of support like that. Neither do Veeam to be honest...they're very cagey with what is being released with new versions. Storage snapshot support for EMC VNX was a bit of a surprise, although rumoured.

Thanks!

pkh
Moderator
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You should use the BE provider.  There is numerous previous discussions which features problems due to the inadvertent use of the VMTools provider.  This is normally due to an upgrade of VMTools which install the VMTools provider.  You should either re-install VMTools WITHOUT the provider or push out the BE remote agent again to the VM which will automatically remove the VMTools provider.

VJware
Level 6
Employee Accredited Certified

I was reading this article - http://www.veeam.com/backup-from-storage-snapshots.html

Especially these lines :-

  1. Triggers a vSphere snapshot for all VMs located on the same storage volume. (As a part of a vSphere snapshot, Veeam’s application-aware processing of each VM is performed normally.)
  2. Triggers a snapshot of said storage volume once all VM snapshots have been created.

vSphere snapshots for application-consistent backups and storage snapshots for fast recovery point objectives (RPOs)

So. coming back to your question If so, is there an alternative method to create full virtual machine backups that don't rely on the Microsoft VSS?  Something that VMware and/or Backup Exec can do completely outside of the guest Windows environment?

Even the Storage Snapshot process uses a vSphere snapshot and this does rely on using the Microsoft Volume Shadow Copy Service. Application-level queiscing is done using this service and there isn't any way around this.

Lastly, regarding which VSS provider to use, have a look @ this KB - https://support.symantec.com/en_US/article.TECH66073.html

Colin_Weaver
Moderator
Moderator
Employee Accredited Certified

To add to VJwares answer

 

When Backup Exec backs up a VMware VM

It talks to VMware's Backup API on the Vmware host (possibly via vCenter) and requests that a snapshot of the complete VM takes place inside the datastore.

VMware's Backup API then makes a call in through the VMware tools to make sure that the content of the VM is quiesced (this is when a VSS request takes place inside the VM) If our remote agent is installed, VMware tools is configured to call our VSS provider, but it is the same trigger mechanism

 

As such we are doing a storage level snapshot - which then to ensure integrity and consistency of the content of the VM makes an internal VSS request inside the VM as well.

 

Backup Exec's snapshot (via the Backup API) is per VM, but at/within the ESX Storage level, I believe there are products that can take a complete datastore snapshot, this is not something offered by BE.

 

 

 

 

teiva-boy
Level 6

Because there is RecoverPoint involved, and it is a BLOCK level CDP product, any block changes to a LUN will get protected and/or replicated.

As such, the normal data flow of a BackupExec VADP backup is to initiate a snapshot of the VMDK, the snapshot is created, and a journal file is created.  The snapshot is mounted, read and transferred/backed up.

The journal file merged into the VMDK, then the snapshot unmounted and deleted...

 

The act of creating the snapshot, the journal file, and the deletion of those files are a lot of BLOCK level/LUN level changes.  As such recoverpoint will have to capture that, and replicate that.

 

There isn't an easy answer to your problem.  You're not alone...  All block level CDP products have this issue.  I know EMC is trying to get recoverpoint to better integrate into their backup products to reduce/remove this issue.  But that is *their* backup technology and this is a Symantec forum ;)

Right now, I usually recommend to folks, get more bandwidth...