Date: Mon, 10 Nov 2014 10:17:57 -0700 From: John Nielsen <lists@jnielsen.net> To: Steven Hartland <killing@multiplay.co.uk> Cc: "freebsd-fs@freebsd.org" <freebsd-fs@freebsd.org> Subject: Re: zpool create on md hangs Message-ID: <1DCE4DFC-45E9-491E-B6E5-77F328979A3B@jnielsen.net> In-Reply-To: <CAPS9%2BStTY2g=qze9qTi9jtkTs4735MZytLFcDb7-9-N8YW7AQw@mail.gmail.com> References: <201411100637.sAA6bJnR051011@maildrop31.somerville.occnc.com> <CAPS9%2BSvm32uX23tUQfismQ%2B1_aiQDe1gyHWQ_BneWSV-cSRhow@mail.gmail.com> <546084FE.80300@multiplay.co.uk> <CAPS9%2BStTY2g=qze9qTi9jtkTs4735MZytLFcDb7-9-N8YW7AQw@mail.gmail.com>
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On Nov 10, 2014, at 2:32 AM, Andreas Nilsson <andrnils@gmail.com> wrote: > > On Mon, Nov 10, 2014 at 10:27 AM, Steven Hartland <killing@multiplay.co.uk> > wrote: > >> >> On 10/11/2014 06:48, Andreas Nilsson wrote: >> >>> On Mon, Nov 10, 2014 at 7:37 AM, Curtis Villamizar <curtis@ipv6.occnc.com >>>> >>> wrote: >>> >>> The following shell program produces a hang. Its reproducible (hangs >>>> every time). >>>> >>>> #!sh >>>> >>>> set -e >>>> set -x >>>> >>>> truncate -s `expr 10 \* 1024 \* 1024 \* 1024` /image-file >>>> md_unit=`mdconfig -a -n -t vnode -f /image-file` >>>> echo "md device is /dev/md$md_unit" >>>> zpool create test md$md_unit >>>> >>>> The zpool command hangs. Kill or kill -9 has no effect. All >>>> filesystems are unaffected but any other zpool or zfs command will >>>> hang and be unkillable. A reboot is needed. >>>> >>>> This is running on: >>>> >>>> FreeBSD 10.0-STABLE (GENERIC) #0 r270645: Wed Aug 27 00:54:29 EDT >>>> 2014 >>>> >>>> When I get a chance, I will try again with a 10.1 RC3 kernel I >>>> recently built. If this still doesn't work, I'll build an r11 kernel >>>> since the code differs from 10.1, not having the svm code merged in. >>>> I'm asking before poking around further in case anyone has insights >>>> into why this might happen. >>>> >>>> BTW- The reason to create a zfs filesystem on an vnode type md is to >>>> create an image that can run under bhyve using a zfs root fs. This >>>> works quite nicely for combinations geom types (gmirror, gstripe, >>>> gjournal, gcache) but zpool hangs when trying this with zfs. >>>> >>>> Curtis >>>> >>>> ps- please keep me on the Cc as I'm not subscribed to freebsd-fs. >>>> >>>> Freezes here on 10.1-RC2-p1 (amd64) as well. >>> ^T says: >>> load: 0.21 cmd: zpool 74063 [zio->io_cv] 8.84r 0.00u 0.00s 0% 3368k >>> >>> I suspect your just seeing the delay as it trim's the file and it will >> complete in time. >> >> Try setting vfs.zfs.vdev.trim_on_init=0 before running the create and see >> if it completes quickly after that. >> >> I tested this on HEAD and confirmed it was the case there. >> >> Regards >> Steve >> > > Sure enough, it has since completed on my box at least. Thanks! I've wondered why it always took so long to create zpools for VM images. JNhome | help
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