Re: Re: [RFC] Multiple Snapshots - Manageability problem

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Dan Kegel schrieb:
On Jan 23, 2008 8:16 AM, Tomasz Chmielewski <mangoo@wpkg.org> wrote:
Vijai Babu Madhavan, Thu, 11 Jan 2007 11:18:13 -0700, wrote:

The problem of DM snapshots with multiple snapshots have been discussed
in the lists quiet a bit (Most recently @
https://www.redhat.com/archives/dm-devel/2006-October/msg00034.html).

We are currently in the process of building a DM snapshot target that scales
well with many snapshots (so that the changed blocks don't get copied to each
snapshot). In this process, I would also like to validate an assumption.
Any news on that?

Still, with multiple snapshots write performance degrades linearly - is
any work done to change that anytime soon?

Yes.  Dan Phillips has implemented a shared snapshot exception store.
You can try it out now if you like; it's at http://zumastor.org.
It feels a bit different from the user's point of view than LVM, though.
It plays well with the device mapper and can be used with any
block device (LVM or non-LVM).

Does it use device mapper (or it just "plays well with the device mapper")? Or is it a totally different technology?

I didn't find it explained very clearly in Zumastor HOWTO on http://zumastor.googlecode.com/svn/trunk/doc/zumastor-howto.html (other than pointers to /dev/mapper/zumatest, which probably means it uses device mapper).



--
Tomasz Chmielewski
http://wpkg.org

_______________________________________________
linux-lvm mailing list
linux-lvm@redhat.com
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

[Index of Archives]     [Gluster Users]     [Kernel Development]     [Linux Clusters]     [Device Mapper]     [Security]     [Bugtraq]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]

  Powered by Linux