From mboxrd@z Thu Jan 1 00:00:00 1970 From: Milan Broz Subject: Re: Problem when creating snashots Date: Wed, 27 Sep 2006 12:36:21 +0200 Message-ID: <451A5425.2010704@redhat.com> References: <77299A0E-4C81-4820-97BF-FB15B1A96FD6@gmail.com> <20060926211407.GA2915@hasse.suse.de> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids The problem with limited number of snapshots is caused by the using big common mempool in dm-io module. (This can happen even you have a lot of free memory...) There are new dm-io patches which introduce new dm-io interface (using private mempools) and solving this type of snapshot limitation. Patches are currently in review and will probably change a bit, but I hope it will in 2.6.19 kernel. Milan -- mbroz@redhat.com The MoonSeeker napsal(a): > Yes I really need it. I have to create a virtual network editor for my > diploma project. So I have found many virtual solutions but the bestest > for our project is OpenVZ. Unfortunatly, OpenVZ don't offer the copy on > write with his solution, after many tests, I have found a solution base= d > on LVM. >=20 > The main idea is to have a Virtual Private Server Core and lot of > Virtual Private Server who are a snapshot of the Virtual Server Core. > Now the problem is the limitation of VLM, I need more than 32 servers > (32 snapshots). Will this limitation incresed in futur futur released o= f > LVM? Or can we broke this limitation? >=20 > Have you a solution, it's relly urgent for me... >=20 > Thanks you >=20 >=20 > Le 26 sept. 06 =E0 23:14, Jan Blunck a =E9crit : >=20 >> On Tue, Sep 26, The MoonSeeker wrote: >> >>> I'd like to create many snaphot of an image but I've got when I >>> attemp to create the 32th snapshot : >>> >>> root@B03:/diplome# lvcreate -s -L150M -n 232 /dev/openvz/vps-core >>> Rounding up size to full physical extent 152.00 MB >>> device-mapper: reload ioctl failed: Ne peut allouer de la m=E9moire >>> Failed to suspend origin vps-core >>> >>> I don't understand the error.. >> >> I'm not a native french speaker (hint!) but I assume you run out of >> memory. >> >> Yes there are limitations to the number of snapshots. For every single >> snapshot we have to allocate memory for copying the chunks to the >> exception >> store. >> >> Do you really need that many snapshots at the same time? >> >> --=20 >> dm-devel mailing list >> dm-devel@redhat.com >> https://www.redhat.com/mailman/listinfo/dm-devel >=20 >=20 > --=20 > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel