REFS+9.5 volume size limitations?

[mkretzer]

Hello,

are there any limits for the size of the REFS volumes which can be used with 9.5 and the new REFS function?

If i understand correctly it makes sense for the full, incr and GFS backups to be on one volume to fully use the functunality, correct? That means the volumes can/should be quite huge.

Windows Dedup has the 64 TB "limit" - is there something simliar with REFS?

Markus

[dellock6]

I think you will have to split data for limiting the failure domain, way before you will hit any refs limit. Maximum file is 16 exabyte and maximum volume is 1 yottabyte!
Also, yes you may want to keep files together to leverage block clone, but still remember to have backups and backup copies in two different storage systems.

[nmdange]

Right now my backup repositories are 44TB in size to stay under the 64TB chkdsk limit with NTFS. Without that limit with ReFS I am definitely going to reformat my disks to consolidate what are currently separate RAID disks into one. However I am going to keep each RAID disk within a single disk enclosure just in case.

[Gostev]

Maximum file is 16 exabyte and maximum volume is 1 yottabyte!

1 YB is theoretical, Windows addresses 16 EB maximum.

[mkretzer]

I wonder: how much sense do dedup storages make in the future?
We did some tests with windows dedup and found out that even with per-VM dedup rate is about 12 % with about 500 VMs (Veeam Dedup on).

Now with REFS we will not have these 12 % dedup between backup files but everything else (GFS, SynFull...) will be "deduplicated" EVEN WITH ENCRYPTION ON...

One question: what will happen it we evacuate a SOBR extend which is REFS to another REFS extend? Will the data still be "deduplicated"?

[dellock6]

Dedupe: it's the same doubt I have, with the addition of S2D , win2016 + ReFS will allow for some really cool designs.
Evacuate: no, because file copy is not a transform operation where Veeam will invoke the block clone api. Unless we do some additonal magic I'm not aware

[mkretzer]

@dellock6: So new feature request from me: Application/Veeam side "Storage VMotion" for backup files between REFS volumes!