Re: [dm-devel] Shared snapshot tests

[Daire Byrne <daire byrne gmail com>]

On Wed, May 5, 2010 at 4:39 AM, Mikulas Patocka <mpatocka redhat com> wrote:
> See the patch that I sent you. Does it improve performance for NON-shared
> snapshots? (eventually, I'll make the same change to shared snapshots too)

The server and RAID I had for testing has now been used for something
else so I am unable to do any more tests atm.

> BTW. what disks and raid array do you use? Is it a hardware or software
> raid?

Hardware (Infortrend) RAID.

> I have found that with Maxtor disks (IDE, SATA and SCSI), you have to
> limit the request size to 256kB, or you get unpredictable performance
> drops.

I played with the request size but it made little difference.

>> Out of interest what are Redhat's plans for this feature? Will it be
>> in RHEL6 or is it going to wait until it is accepted upstream and then
>> make it into some later Fedora release? Could it be easily backported
>> to RHEL5 do you think?
>
> Not in RHEL 6.0. Maybe in 6.1.
>
> It's not planned to backport to 5.x.

Okay. Thanks. I will try and test this again when I get some hardware.

Daire