In the previous post of this series, I showed you how to check and properly configure your environment to be sure you can safely use storage snapshots. This time, I will show you how to configure and monitor snapshots on HP LeftHand.
Create your LUN Snapshot schedule
Once your datastore is hosting only the VMs you want to protect using VESS, it’s time to configure snapshots. Using the P4000 CMC, select the LUN you want to snapshot:
The second tab on the right is called Snapshots. Here you will find a context menu about snapshot tasks you can run. The first one is what we need: “New schedule to snapshot a volume“:
This command opens a new menu where you are going to configure the scheduled snapshots:
In my example, I configured the schedule to create a new snapshot every hour. If you need a different frequency, you can run it as frequent as every minute. Be careful to avoid a schedule that can put an excessive load on your storage.
To avoid the complete consumption of your storage, remember to configure the retention period of your snapshots. You can remove older snapshots by time (“maximum time to retain a snapshot“) or by number of snapshots (“Maximum number of snapshots to retain“). In my example, I’m creating 1 snapshot every hour, and I’m going to keep a full day of history.
A note about “Application-Managed Snapshot“: snapshots are usually taken at a specific “point-in-time”, but an application writing to that volume may not be quiesced. Thus, data may be in flight or cached ant the actual data on the volume may not be consistent with the application’s view of the data. In contrast, application-managed snapshot is taken while the application using the volume is quiesced, assuring data consistency. In order to use application-managed snapshots, you will need however to install the HP LeftHand VSS provider into Windows VMs beeing snapshotted. This is a decision you have to take in account, since you are then going to use also Veeam VSS provider to do usual backups, and different VSS provider do not work so good together.
After the first day of execution of this schedule, your storage will show you a screen like this one:
Here we go! you now have 24 hourly snapshots of your LeftHand LUN.
In the next post of this series, I will show you how to configure and browse LeftHand snapshots from Veeam Backup & Replication.