Now that we know What is Snapshot and how we can create one from HTML5 client, lets understand the snapshot best practices while working with VMware and what are it's limitations.
Snapshot Best Practices
For better performance, VMware has suggested some best practices while using snapshots in vSphere environment.
Do not use snapshots as backups.
The snapshot file continues to grow in size when it is retained for a longer period. This can cause the snapshot storage location to run out of space and impact the system performance. Hence do not use a single snapshot for more than 72 hours.
For a better performance use only 2 to 3 snapshots on a virtual machine even though maximum of 32 snapshots are supported in a chain from VMware.
When using a third-party backup software, ensure that snapshots are deleted after a successful backup. Snapshots taken by third party software (through API) may not appear in the Snapshot Manager. Routinely check for snapshots through the command-line.
Snapshot Limitations
Undoubtedly snapshot is one of the great feature offered by VMware. However it has some limitations -
Firstly, Snapshots are only useful as short-term solutions for capturing point-in-time virtual machine states and are not appropriate for long-term virtual machine backups. If the files containing a virtual machine are lost, its snapshot files are also lost. Also, large numbers of snapshots are difficult to manage, consume large amounts of disk space, and are not protected if there is hardware failure.
VMware does not support snapshots of raw disks, RDM physical mode disks, or guest operating systems that use an iSCSI initiator in the guest.
Virtual machines with independent disks must be powered off before you take a snapshot. Snapshots of powered-on or suspended virtual machines with independent disks are not supported.
Quiesced snapshots require VMware Tools installation and guest operating system support.
Snapshots are not supported with PCI vSphere DirectPath I/O devices.
Snapshots do not support some disk types or virtual machines configured with bus sharing. If you require bus sharing, consider running backup software in your guest operating system as an alternative solution. If your virtual machine currently has snapshots that prevent you from configuring bus sharing, delete (consolidate) the snapshots.
Snapshots can negatively affect the performance of a virtual machine. Performance degradation is based on how long the snapshot or snapshot tree is in place, the depth of the tree, and how much the virtual machine and its guest operating system have changed from the time you took the snapshot. Also, you might see a delay in the amount of time it takes the virtual machine to power on. Do not run production virtual machines from snapshots on a permanent basis.
If a virtual machine has virtual hard disks larger than 2 TB, snapshot operations can take much longer to finish.
That's it for now.
Thank you for reading!
*** Explore | Share | Grow ***
Comments