[dm-devel] Shared snapshots
Mikulas Patocka
mpatocka at redhat.com
Wed Jan 6 14:38:00 UTC 2010
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...
Mikulas
More information about the dm-devel
mailing list