Copy Job merge slow (REFS)

[skumflum]

We rushed out and installed Windows 2016 to utilize the new REFS/VEEAM 9.5 feature. Our most pressing concern was to bring down the merge time of the Copy Jobs but it has not.
Currently it takes over 120 hours to merge 4TB incremental into the 30TB VBK file. It is using [fast clone] so I guess that REFS features is detected and used.

The backup SAN is not blistering fast but it’s not a slow NAS (12x6TB SAS 7K HPE MSA 2040)

Is this to be expected?

[foggy]

Hi Søren, what were the speeds prior moving to Windows 2016?

[skumflum]

Aprox the same

[foggy]

I'd contact support with this, since the speed indeed doesn't look expected in case fastclone is fully utilized.

[kubimike]

its so funny I saw this. I have another post going on about how my Windows 2016 box experiences random freezes and BSOD. Microsoft turned on some features to tag things in memory. Now when doing a [fast clone] to make a synthetic full it went from 20 seconds to 2 hours 45 mins on any job.

[skumflum]

It must be related.

[Salm]

This may or may not be related, but how did you guys format your ReFS volumes ?

See veeam-backup-replication-f2/refs-4k-hor ... 40629.html

This is a memory issue, but who knows what else it could cause.

[skumflum]

It is formatet 4K... I must have made a error as I thought that it was 64K.

But even though it's 4K there also seems to be problems with 64K?

The merge resultet in a unresponsive repository and BSOD. After a reboot I could not access the drive and diskpart just froze up. After 30-40 min it came back

[kubimike]

not aware of any issues with 64k. If you look in the event log filter system event id 1001. Curious what the bugcheck is

[btmaus]

Using 64K formatted ReFS here. Have been migrating more and more of my Daily backup jobs over to it from a dedupe appliance. So far, has been extremely fast and not a single issue. Make sure you are using 64K!