[dm-devel] Shared snapshots

[haad]

On Thu, Jan 7, 2010 at 9:42 AM, Pasi Kärkkäinen <pasik at iki.fi> wrote:
> On Wed, Jan 06, 2010 at 09:38:00AM -0500, Mikulas Patocka wrote:
>> Hi
>>
>> I uploaded new code for shared snapshots at
>> http://people.redhat.com/mpatocka/patches/kernel/new-snapshots/devel/
>>
>> Changes:
>> - two queues, one for reads and one for writes, to improve read latency
>> when the device is write-congested
>> - limit number of reallocations in flight (VM subsystem sends all writes
>> at once and without limit it creates big lags).
>> - fixed one place where it didn't handle on-disk errors
>> - simplified bitmap creation, removed some unneeded code
>> - new macro for error reporting, as suggested by Zdenek
>> - some comments added
>> - DM_ prefix added to some macros
>>
>> Userspace for lvm 2.02.53 is at
>> http://people.redhat.com/mpatocka/patches/userspace/new-snapshots/lvm-2.02.54/
>>
>> Please, someone, do offensive testing with this --- i.e. apply the
>> patches, try it, and try all possible lvm commands with it, try to stress
>> and crash it in various ways, etc. If we wait with testing until Alasdair
>> reads the code, it won't get much testing...
>>
>
> Sorry for a stupid question, but what does "shared" mean? Support for CLVM?

No all snapshots share one, common exception store I think.



-- 


Regards.

Adam