What versions of VMware are supported
ESX or ESXi 4.0 or higher.
Will the ESX free version work
We can’t backup from the ESX free version. The free version doesn’t allow access to the VMware storage APIs we need to backup data.
What license do I need
Under licensed features, need the storage APIs listed.
What is Ignore unallocated sectors
Use CBT to find out what parts of VMDKs have never been used, and skip those sectors to speed backup.
What is quiesce data
When taking the snapshot of a VM, we can ask VMware to quiesce data. VMware will signal the VMware tools running in the guest operating system, which will signal the operating system (via VSS in Windows). The programs on the guest operating (for example, Microsoft SQL server) and the file system of the operating system should put their data files in a consistent state like they would during a shutdown. Once that’s done, the snapshot is taken, and the guest operating system resumes normal operation. This is to allow a VM backup to be restored and used immediately without needing to wait for file system or database repairs.
What is CBT
Changed Block Tracking is a feature of VMware that timestamps changes to blocks of disk so later backups can skip copying blocks of disk that haven’t changed since the last backup.
What do I need to use CBT
To enable CBT the following VMware conditions must be met:
- The host must be ESX/ESXi 4.0 or later
- The virtual machine owning the disks to be tracked must be hardware version 7 or later
- I/O operations must go through the ESX/ESXi storage stack. So NFS is supported, as is RDM in virtual compatibility mode, but not RDM in physical compatibility mode. Of course VMFS is supported, whether backed by SAN, iSCSI, or local disk
- CBT must be enabled for the virtual machine (see below)
- Obviously, virtual machine storage must not be (persistent or non-persistent) independent disk mode, meaning unaffected by snapshots
- The virtual disk must be located on a VMFS volume, backed by SAN, iSCSI, or local disk. RDM is not VMFS
- The virtual machine must have zero (0) snapshots when CBT is enabled, for a clean start
Can I backup a VM without snapshotting it
Not through the VMware integration. If VMware can’t make a complete snapshot of a VM, we recommend backing it up by installing the backup agent on its guest operating system.
Can I backup VMDKs in the persistent mode
Not through VMware integration. Persistent mode means that a VMDK can’t have a snapshot taken (though VMware will still snapshot other parts of a VM). Without a snapshot we can’t know that the guest operating won’t be changing the contents of the virtual disk while we are backing it up. There’s one exception, if the VM is powered down then we’ll be able to get exclusive access to the VMDK, but the VM can’t be powered on until the backup is complete. We recommend installing the backup agent in the guest operating system.
How do I restart host services
Follow the instructions provided by VMware found here.
Can I backup RDM disks
Only if it’s used in the virtual mode (allowing for snapshots)
What’s the max VMDK size that can be backed up
If VMware is unable to create a snapshot, it’s too big.
Does Disaster Recovery create a user for itself in vCenter
No, it continues to use the username it was given when first setup. If the password on that account is changed, or the account is disabled or removed, VM backups will fail.