Sunday, May 29, 2011

Veeam Backup and Replication Prep Checklist

I recently implemented Veeam Backup and Replication in my employers vSphere environment. Previous to using Veeam, 'traditional' in-guest agent backups had been used. While agent / OS based backups aren't necessarily bad, they are not the most effective way to get things done in a virtual environment. To get the most benefit from a virtualized environment and realize some other truly beneficial 'side effects' a hypervisor level backup should be used.

The downsides to agent / OS based backup methods in a virtual environment are: they consume CPU cycles on each VM and consequently take away from the host on the whole, they are slow because they have to check every file, they can also cause access times to be reset on every file which may not be ideal, and in event of a full restore, there is likely some requirement to get a base OS up and running (time consuming). The list goes on but in summary guest OS agent based backups are not time effective or host resource efficient.

Now when working with backups at the hypervisor level, there are some prerequisites to have in place for backups to work properly. One of the more important (painful to correct) items is ensuring any data that will get backup up is on hypervisor backed storage. By this I mean the backup tool, because it operates at the hypervisor level of the stack, can not see storage that a guest may have direct access to via physical RDM, or in Guest iSCSI mapped luns. Resolving this issue (if possible) can be a good source of downtime for those who don't have sVMotion enabled licenses (like myself). There have been a handful of articles that show little to no performance trade-offs between vmdk backed storage and RDM or in guest mapped luns.

So during my Veeam Backup and Replication implementation I created this Guest VM checklist the ensure things when a bit more smoothly the first time through.
  • Ensure CBT is set to false on all guest vDisks - Veeam will fix automatically
  • Ensure Data to be backed up is on vmdk or virtual RDM backed storage
  • Ensure vDisks are not set as persistent - snapshots are key to the backup process
  • Put Page / Swap file on seperate vdisk and Exclude the vdisk from backup - optional but will save on backup / replicating of pagefiles
This isn't meant to be a advertisement for Veeam but in short it was the selected solution for the following reasons:
  • Veeam is the leader at innovating backup and disaster recovery features in the virtualization space. It is a product built from the ground up for virtualized environments and the feature additions over each major release are significant.
  • vPower NFS and Instant Recovery offer incredible value - you must try these if you have not.
  • Ability to truly validate backups, by starting up the VM's from the backups in an isolated setting to ensure application functionality.
  • "Lab" functionality that is great for testing patches, upgrades, etc
  • For you Hyper-V folks, support is coming in Veeam v6!
  • There is substantially more value in a Veeam solution than just 'backup'

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