From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4C17E56D.5010808@redhat.com> Date: Tue, 15 Jun 2010 16:41:17 -0400 From: Takahiro Yasui MIME-Version: 1.0 References: <4C179B03.2000102@cfl.rr.com> <20100615164709.GG15698@agk-dp.fab.redhat.com> <4C17BC76.7090506@cfl.rr.com> <4C17D1BF.9010103@redhat.com> <4C17E16B.8000708@cfl.rr.com> In-Reply-To: <4C17E16B.8000708@cfl.rr.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] Why does every lvm command insist on touching every pv? Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: Phillip Susi Cc: linux-lvm@redhat.com On 06/15/10 16:24, Phillip Susi wrote: > On 6/15/2010 3:17 PM, Takahiro Yasui wrote: >> Everytime lvm command is executed, all PVs are accessed. >> >> This is a known issue and what we should fix. If there are a lot of >> PVs, execution of lvm command could take a long time. The scan also >> affects error recovery time of lvm mirror. >> >> This is an old reference. >> >> Introduce metadata cache feature >> https://www.redhat.com/archives/lvm-devel/2009-April/msg00014.html > > This seems to limit the number of metadata copies on pvs that are > accessed to one, but I am seeing even block devices that are not pvs > accessed, like it is scanning for new pvs. This patch seems like it > would help some though, but it is over a year old. Did it never get > applied? As for accessing block devices, you can limit accesses to those devices by filter option in lvm.conf. This is an example which allows accesses only to /dev/sd* filter = [ "a|/dev/sd|", "r|.*|" ] You can specify more strict rule like filter = [ "a|/dev/sd[a-z]|", "r|.*|" ] For my patch, I posted it one year ago but I need to have more discussion how to solve this issue on lvm-devel. Thanks, Taka