[SOLVED] ZFS Restore from PBS Very Slow

[johndoe86x]

Hi, all,

I'm performing a restore of a VM from PBS backup. The connection is a bonded 10G going from spinning rust to SSDs. The total restore size is 1.07TB. Here is the progress so far:



Any help speeding this up (or future backup restores) would be greatly appreciated.

Cheers!

 

[Dunuin]

You could enable relatime for your PBS datastore, so not every read operation is causing an additional write operation. In case you are using ZFS you could also increase the recordsize to 1M, so the data to metadata ratio gets better. Otherwise there isn't much you can do to make it faster. A 1TB Restore is probably doing something like 500,000x 2MB random reads. So a lot of IOPS hitting the HDDs.

 

[johndoe86x]

You could enable relatime for your PBS datastore, so not every read operation is causing an additional write operation. In case you are using ZFS you could also increase the recordsize to 1M, so the data to metadata ratio gets better. Otherwise there isn't much you can do to make it faster. A 1TB Restore is probably doing something like 500,000x 2MB random reads. So a lot of IOPS hitting the HDDs.

Thanks for your reply, Dunuin. How would I go about enabling relatime for the PBS datastore? Just to verify, the command to set the record size: sudo zfs set recordsize=1M tank/backups. I'm also aware that this only applies to new data.

 

[Dunuin]

Thanks for your reply, Dunuin. How would I go about enabling relatime for the PBS datastore? Just to verify, the command to set the record size: sudo zfs set recordsize=1M tank/backups. I'm also aware that this only applies to new data.

Enabling atime then would be sudo zfs set relatime=on tank/backups