Re: netapp-alike snapshots?

[Ulli Horlacher <framstag@rus.uni-stuttgart.de>]

On Tue 2017-08-22 (22:36), Roman Mamedov wrote:

> > My users want the snapshots locally in a .snapshot subdirectory.
> > Because Netapp do it this way - for at least 20 years and we have a
> > multi-PB Netapp storage environment.
> 
> Just a side note, you do know that only subvolumes can be snapshotted on Btrfs,
> not any regular directory? And that snapshots are not recursive, i.e. if a
> subvolume "contains" other subvolumes (hint: it really doesn't), snapshots of
> the parent one will not include content of subvolumes below that in the tree.

Yes, I know this. But thanks for your hints! (Other readers here may be
not aware of this)


> I don't know how Netapp does this

I am only a Netapp/waffle user, so I know no internals.
Netapp is not Linux based and definitly a lot older than btrfs.


> from the way you describe that setup it feels like with Btrfs you're
> still in for some bad surprises and a part of your expectations will not
> be met.

I will take care :-)


> Do you plan to make each and every directory and subdirectory a subvolume

No. My idea is to place a symlink in every subdirectory pointing to the
snapshot directory. Not yet programmed...
I was hoping someone already has implemented such a feature.


-- 
Ullrich Horlacher              Server und Virtualisierung
Rechenzentrum TIK         
Universitaet Stuttgart         E-Mail: horlacher@tik.uni-stuttgart.de
Allmandring 30a                Tel:    ++49-711-68565868
70569 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<20170822223647.350ca27d@natsu>