Forum Discussion

AdN's avatar
AdN
Level 4
2 years ago

VMware backup with HotAdd?

Hi,

Is anyone using the HotAdd transport method for backing up VMware virtual machines?

I tried it for a few days and achieved about 10x faster backups than with NBD. But then we had an issue that for one VM the virtual SCSI devices mapped on the media server VM have not been released. This caused snapshot consolidation errors on the client VM until one manually removed the virtual SCSI devices from the media server VM. 

Does this happen often or are we just having bad luck? 

Why is NBD so much slower than HotAdd? Both methods are using the same storage and network.

Regards,
Bernd

  • Michal_Mikulik1's avatar
    Michal_Mikulik1
    Moderator
    2 years ago

    Hello,

    HotAdd backups have some limitations, for example check this if it does not apply: https://www.veritas.com/support/en_US/article.100014472.

    HotAdd and NBD dont use the same network. With NBD, ESX host is controlling the network flow, using NFC protocol, while HotAdd Backup Host is sending backed-up data through "usual" network as any other data.

    I you have issues with backup duration and you have MSDP storage units, consider using accelerator for VM backups.

    Regards

    M.

  • AdN's avatar
    AdN
    Level 4
    2 years ago

    Thanks for your reply. The backup media server is a RHEL 8 VM with SCSI controller type "VMware Paravirtual".

    The backup client that caused issue indeed has SCSI controller "LSI Logic SAS". Unfortunately all the Windows VMs use "LSI Logic SAS" by default and have VMware tools installed using default options and not the driver included. The first Windows version that recognizes a boot disk using "VMware Paravirtual" controller is Windows Server 2022. 

    Messing around with SCSI controller type, adding disks and reinstalling VMware Tools with full installation to include the driver.

    https://kb.vmware.com/s/article/1010398

    We have no MSDP storage units. VMware VMDK storage is NFS on Netapp AFF A400 and backup target is BasicDisk NFS on Netapp FAS 2720.

    Regards,
    Bernd