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Slow speed hotadd backup / restore

Level 4

Hi all,

I am looking for the reason for slow speed backup / restore with transport hotadd

Virtual media-server; ethernet link 10000 Mb/s

Esx media server and client are the same

Hardware platform for vmware has high performance

Buffer tuning complete

Backup / restore speed ~ 17 MB/s

What is the cause of slow speed?



Level 6
Partner    VIP    Accredited Certified

Hot add has the worst performance IMO. Why are you using it instead of NBD/SAN?

Partner    VIP   

And you are restoring from what media - disk, tape (multiplex or not) ?

Level 6
Partner    VIP    Accredited Certified

Just think about it - you have all of the read and write I/O on the same VM, plus the additional overhead on the ESX server.

See this TN:

..... although this incurs more overhead on the physical ESX/ESXi host  ..... 

There is a separate backup segment, it uses SAN transport. Backup speed up to 350 MB / s, restore speed only 60 MB / s. Other segments use NBD transport. Backup / restore speeds are moderate.

I decided to test, and made a stand for checking the speed of hotadd. To store backup images, I configured the storage unit on the local disk. If, as a result, the backup/restore speed rises to 100 MB / s, then i can raise the question of connecting external external storage to the media server.

Back to hottadd transport again.

I am interested in the ability to perform the backup / restore virtual machine procedure at high speed. But the main thing is still the ability to restore a virtual machine at high speed.

An example of a circuit is given in the attachment.


1) do I understand correctly that in the case of a backup, the snapshot will be created on the ESXi Datastore?

2) do I need to configure the NFS client on BackupHost1, and the NFS server on ESXi?

3) is the requirement that Server1 and BackupHost1 be on the same ESXi host ?;

4) how to configure transmission over SAN from BackupHost1 to Media Server1?

I would be grateful for your answers.