From mboxrd@z Thu Jan 1 00:00:00 1970 References: From: Zdenek Kabelac Message-ID: <5702217A.9090206@redhat.com> Date: Mon, 4 Apr 2016 10:10:34 +0200 MIME-Version: 1.0 In-Reply-To: Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] LVM Performance issues when creating many Volume groups 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"; format="flowed" To: linux-lvm@redhat.com, syed1.mushtaq@gmail.com Dne 1.4.2016 v 19:30 Syed Mushtaq napsal(a): > Hi linux-lvm, > > In my setup I am trying to map a backend ISCSI storage volume to a volume > group. I am using that volume group as a Disk for VMs in Xen. However, If I > create many volume groups, future volume group creates are slowing down. In my > test I have about 600 VGs. Each VG has a single LV. Here are the commands that > are taking a lot of time > > create volume group ( 4.8s ): /usr/sbin/vgcreate VG_XenStorage-1fe15110-61f6- > 856f-8ae2-8e42e45a4316 /dev/disk/by-id/scsi-36f47acc1000000007931637600000523 > > list lvs inside volume group ( 2.4s ): /usr/sbin/lvs --noheadings --units b -o > +lv_tags /dev/VG_XenStorage-1fe15110-61f6-856f-8ae2-8e42e45a4316 > > check if LVM volume group exisits (2.5s) : /usr/sbin/vgs > VG_XenStorage-1fe15110-61f6-856f-8ae2-8e42e45a4316 > > I am using LVM 2.0.88. Is this a known issue? Any workarounds? > > Thanks for you help. > -Syed Hi Lvm2 upstream is now working on release 2.02.150. Your version 2.02.88 is from Aug 2011. If you want to get some fixes for your version I'm afraid you will need to bother your distro maintainer. You may use '-vvvv' debug to see where it is delayed. Also 'strace -ttt' is helpful. Common problems are: - Users do not set 'correct' lvm.conf filters, so lvm2 with each command has to unnecessarily scan all devices in your system and some might be pretty slow to read... - Very long set of files stored in /etc/lvm/archives (or wherever your distro has this directory). - Of course using 5 years old software is out-of-radar of upstream developers... Regards Zdenek