REFS, Block Cloning, Storage Spaces Simple Volumes and Seeding data

[stueng]

Hi everyone.. hoping for some insights into some questions/concerns that we have:

We are a cloud connect provider and are looking to leverage block cloning benefits of using the REFS file system. As a service provider we have the requirement to seed data onto local devices that we can transport around. We use CEPH as a backend storage system, for various reasons we would like to keep the size of the iSCSI disks to a managable size, say maximum 10TB per disk. So for example we would provision a customer with one or more 10TB iSCSI disks.

Questions:
Seeding: If we want to seed the customers initial backup onto a transportable device, how can we be sure that when we import the backup that it will be subject to the benefits of block cloning? In theory the moving of the backups across file systems / block devices could result in a loss of whatever reference block cloning technology uses?

Storage Spaces: As explained above, we would like to create customer repositories by presenting multiple iSCSI disks rather than one large iSCSI disk (there are few reasons for this, some related to CEPH, some to do with performance).. block cloning would suggest that the technology works at the block level.. therefore my question is.. is is possible to use block cloning on a storage spaces simple volume that spans multiple block devices?

Thanks in advance for any responses.

[Gostev]

Hello!

Seeding: not sure I follow you here. The initial backup that is seeded is a full backup, and being a single file there's no block cloning in the picture? In other words, there's nothing to lose in the first place at this point. However, the following full backups created on the service provider side will benefit from block cloning normally.

Storage spaces: yes, block cloning will work fine with Storage Spaces. However, Microsoft will not support Storage Spaces in such configuration (they require direct access to hard drives - no abstraction layers can be present whatsoever, as per their system requirements).

Thanks!

[stueng]

I think MS have back tracked on their stance regarding storage spaces on non-direct disks.. Im sure I have seen posts in here somewhere and emails in the community digest.. struggling to find them at the moment though.

[Gostev]

Those posts were regarding ReFS, and not Storage Space. Source: I am the person who writes the community digest