From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takahiro Yasui Date: Wed, 21 Apr 2010 11:18:57 -0400 Subject: [BUG-REPORT] mirror legs in the same PV with --alloc anywhere In-Reply-To: <1271495752.5449.53.camel@localhost> References: <4BC7817E.7080407@redhat.com> <20100415220308.GO13021@agk-dp.fab.redhat.com> <4BC88002.10803@redhat.com> <1271495752.5449.53.camel@localhost> Message-ID: <4BCF1761.7080805@redhat.com> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 04/17/10 05:15, brem belguebli wrote: > I think things are not clear about this one, and everyone is confused. I believe that we agreed on what was our goal through this thread. > Malahal (from IBM) and you have posted a few weeks ago design proposals > and patches to add mirrored log capabilities and also the fact that it > could be located on the mirror legs (pv in our cases) by using > alloc_anywhere. > > alloc_anywhere, as described in the man page is to let LVM put the data > logical extents where ever it wants (not strict allocation policy) which > is, in case a mirror is expected completely a nonsense. Yes, you are right. We can't expect where logical extents are allocated for '--alloc anywhere' > You may, (this is a suggestion), when lvcreating a mirror with > mirrored-log > - force strict allocation for the LE's (otherwise it' nonsense) > - put the mirrored log leg on each PV > - And may be disable alloc anywhare when creating mirrors ? I think that 'mirrored log' capability is very useful and enhancing availability is our next step. It is helpful if users can directly build a mirror volume, which has a mirrored log and is built on two physical devices and also each physical device contains a mirror leg and a mirror log, by a simple command line. I hope this explanation would be helpful. Thanks, Taka