On Wed, Nov 12, 2008 at 08:42:00PM -0800, Jeremy Chadwick wrote: > ... > > > On Wed, Nov 12, 2008 at 05:58:26PM +0000, Tim Bishop wrote: > > > > I've been playing around with snapshots lately but I've got a problem on > > > > one of my servers running 7-STABLE amd64: > > > > > > > > FreeBSD paladin 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #8: Mon Nov 10 > > > > 20:49:51 GMT 2008 [EMAIL PROTECTED]:/usr/obj/usr/src/sys/PALADIN amd64 > > > > > > > > I run the mksnap_ffs command to take the snapshot and some time later > > > > the system completely freezes up: > > > > > > > > paladin# cd /u2/.snap/ > > > > paladin# mksnap_ffs /u2 test.1 > > > > > > > > It only happens on this one filesystem, though, which might be to do > > > > with its size. It's not over the 2TB marker, but it's pretty close. It's > > > > also backed by a hardware RAID system, although a smaller filesystem on > > > > the same RAID has no issues. > ... > Then in my book, the patch didn't fix anything. :-) The system is > still "deadlocking"; snapshot generation **should not** wedge the system > hard like this. > > Also, during my own testing, I am always able to use Ctrl-T to get > SIGINFO from the running process (mksnap_ffs). That behaviour does not > change for me. > > The rest of the below information is good -- but I'm confused about > something: is there anyone out there who can use mksnap_ffs on a > filesystem (/usr is a good test source) and NOT experience this > deadlocking problem?
I hadn't ever tried until I saw your message. Granted, I'm using a smaller file system (I doubt that I have a toital of as much as 2 TB in all my machines combined), and I'm running i386, vs. amd64. But it ran just fine. I wasn't able to test SIGINFO; it finished before I had a chance. (I ran it under time(1); wall clock time was 0.91 sec.) > Literally *every* FreeBSD box I have root access > to suffers from this problem, so I'm a little baffled why we end-users > need to keep providing debugging output when it should be easy as pie > for a developer to do "dump -0 -L -a -f /path/fs.dump /usr" and watch > their system wedge. Well, I routinely use dump/restore pipelines to copy file systems around; never had a problem with it. > ... For reference: freebeast(7.1-P)[9] uname -a FreeBSD freebeast.catwhisker.org 7.1-PRERELEASE FreeBSD 7.1-PRERELEASE #127: Wed Nov 12 05:16:20 PST 2008 [EMAIL PROTECTED]:/common/S3/obj/usr/src/sys/FREEBEAST i386 freebeast(7.1-P)[10] ls -la total 4 drwxrwxr-x 2 root operator 512 Nov 12 20:53 . drwxr-xr-x 14 root wheel 512 Jan 22 2008 .. freebeast(7.1-P)[11] /usr/bin/time -l mksnap_ffs /S2/usr test.1 0.91 real 0.00 user 0.05 sys 976 maximum resident set size 3 average shared memory size 627 average unshared data size 109 average unshared stack size 104 page reclaims 0 page faults 0 swaps 1 block input operations 230 block output operations 0 messages sent 0 messages received 0 signals received 101 voluntary context switches 34 involuntary context switches freebeast(7.1-P)[12] ls -la total 1460 drwxrwxr-x 2 root operator 512 Nov 12 20:54 . drwxr-xr-x 14 root wheel 512 Jan 22 2008 .. -r--r----- 1 root operator 2410791056 Nov 12 20:54 test.1 freebeast(7.1-P)[13] Peace, david -- David H. Wolfskill [EMAIL PROTECTED] Depriving a girl or boy of an opportunity for education is evil. See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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