From owner-freebsd-fs@FreeBSD.ORG Mon Oct 3 21:36:50 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 56126106564A for ; Mon, 3 Oct 2011 21:36:50 +0000 (UTC) (envelope-from olivier@gid0.org) Received: from mail-qy0-f182.google.com (mail-qy0-f182.google.com [209.85.216.182]) by mx1.freebsd.org (Postfix) with ESMTP id ED3FD8FC12 for ; Mon, 3 Oct 2011 21:36:49 +0000 (UTC) Received: by qyk4 with SMTP id 4so4519436qyk.13 for ; Mon, 03 Oct 2011 14:36:49 -0700 (PDT) MIME-Version: 1.0 Received: by 10.229.2.209 with SMTP id 17mr424024qck.29.1317677807853; Mon, 03 Oct 2011 14:36:47 -0700 (PDT) Received: by 10.229.224.82 with HTTP; Mon, 3 Oct 2011 14:36:47 -0700 (PDT) In-Reply-To: References: <20111002020231.GA70864@icarus.home.lan> Date: Mon, 3 Oct 2011 23:36:47 +0200 Message-ID: From: Olivier Smedts To: Xin LI Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: "freebsd-fs@freebsd.org" , Ivan Voras Subject: Re: is TMPFS still highly experimental? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Oct 2011 21:36:50 -0000 Le lundi 3 octobre 2011, Xin LI a =E9crit : > On Sun, Oct 2, 2011 at 3:33 PM, Ivan Voras wrote: >> On 02/10/2011 07:27, Xin LI wrote: >> >>> The problem Ivan have asserted was not confirmed by anyone who have >>> swap configured properly. Gleb have pointed out that it might be >>> related to a series of integer overflow by the way (he have also fixed >>> a lot of tmpfs issues by the way). >> >> Well, instead of guessing I can point you to the way I got the original >> situation - you said you have ZFS configured so it would be easy for you >> to check. >> >> You should to something like this: >> >> - configure your system to the best of your abilities (but post what >> you did different from the defaults) > > It's mostly "normal" configuration -- 6GB RAM, 14GB swap, ZFS as /usr; > > The following sysctl tweaks were done to make postgresql start (these > are not scientific, just large enough to make it work): > > kern.ipc.shmmax=3D4294967296 > kern.ipc.shmall=3D1048576 > >> - install postgresql (8.4+, but I don't think the version is >> important), configure it so it gets half the system memory or 2/3 the >> system memory for its shared_buffers. > > Configured to half of system memory (3072MB). > > # ipcs -a > Message Queues: > T ID KEY MODE OWNER GROUP CREATOR > CGROUP CBYTES QNUM > QBYTES LSPID LRPID STIME RTIME CTIME > > Shared Memory: > T ID KEY MODE OWNER GROUP CREATOR > CGROUP NATTCH SEGSZ CPID LPID ATIME > DTIME CTIME > m 65536 5432001 --rw------- pgsql pgsql pgsql > pgsql 6 3295936512 2130 2130 10:57:12 > 11:09:17 10:57:12 > > Semaphores: > T ID KEY MODE OWNER GROUP CREATOR > CGROUP NSEMS OTIME CTIME > s 65536 5432001 --rw------- pgsql pgsql pgsql > pgsql 17 11:09:25 10:57:12 > s 65537 5432002 --rw------- pgsql pgsql pgsql > pgsql 17 10:57:12 10:57:12 > >> - install pgbench > > Done. > >> - initialize pgbench so that the database definitely is larger than the >> entire memory you got (NOTE: THIS IS NOT A CONTRIVED TEST - lots of >> databases in practice are larger than the RAM in the server). > > Initialized with pgbench -i -s 500 pgbench. > >> - run pgbench & observe the results. > > pgbench -t 20000 -c 64 -S pgbench > > Can't seem to reproduce: > > # df -Httmpfs > Filesystem Size Used Avail Capacity Mounted on > tmpfs 10G 69k 10G 0% /tmp > > Any suggestions? Try reducing the swap size to less than the RAM size. No "configuration issue", try with some RAM + swap that should fit all. And please excuse if we're not speaking of the same tmpfs caveat :-) > >> This should create really bad contention problem for memory between >> postgresql and ZFS, which should manifest itself in tmpfs shrinking to 0 >> bytes free. >> >> If you don't get this problem then great, it might be solved! >> >> >> (for more info on pgbench, see this: >> http://www.westnet.com/~gsmith/content/postgresql/pgbench-scaling.htm). >> >> _______________________________________________ >> freebsd-fs@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-fs >> To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" >> > > > > -- > Xin LI https://www.delphij.net/ > FreeBSD - The Power to Serve! Live free or die > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" > --=20 Olivier Smedts _ ASCII ribbon campaign ( ) e-mail: olivier@gid0.org - against HTML email & vCards X www: http://www.gid0.org - against proprietary attachments / \ "Il y a seulement 10 sortes de gens dans le monde : ceux qui comprennent le binaire, et ceux qui ne le comprennent pas."