Bug 144416

Summary:	[panic] Kernel panic on online filesystem optimization
Product:	Base System	Reporter:	sa <admin>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Open ---
Severity:	Affects Only Me	Keywords:	crash
Priority:	Normal
Version:	7.1-RELEASE
Hardware:	Any
OS:	Any

Description sa 2010-03-02 08:10:01 UTC

During online filesystem optimization system can go to kernel panic on
certain circumstances.

Our case was raid 0+1, ar0: 953877MB <nVidia MediaShield RAID0+1 (stripe
64 KB)> status: READY

with /var mounted on /dev/ar0s1f (ufs, NFS exported, local, soft-updates,
fsid 382aad491192146c)

Server role is network gateway, firewall, squid-proxy, mail server and
some monitoring stuff.  /var is heavily used by squid cache and mail-store.

Apparently, we hit online fs optimization threshold, which is (minfree-2
percent) < 6.5 (current defrag level). In messages there are messages on
fs going from TIME to SPACE optimization and it went fine, but after message
fs going from SPACE to TIME there is kernel panic with following data:

dev = ar0s1f, block = 29238692, fs = /var
panic: ffs_blkfree: freeing free frag
cpuid = 0 
Uptime: 320d3h29m24s
Physical memory: 2035 MB
Dumping 270Mb

Maybe it-s already known issue, but better repost, than forget.

Fix: 

Avoid using online filesystem optimization by good recipes given here
http://lists.freebsd.org/pipermail/freebsd-stable/2007-April/034711.html,
or better use of planning file system.
How-To-Repeat: Non tried as it-s production-use server.

Comment 1 Mark Linimon freebsd_committer

2010-03-04 04:09:51 UTC

Responsible Changed
From-To: freebsd-bugs->freebsd-fs

Over to maintainer(s).

Comment 2 Eitan Adler freebsd_committer

2017-12-31 08:00:46 UTC

For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

Mail being skipped

Comment 3 Graham Perrin freebsd_committer

2022-10-17 12:18:21 UTC

Keyword: 

    crash

– in lieu of summary line prefix: 

    [panic]

* bulk change for the keyword
* summary lines may be edited manually (not in bulk). 

Keyword descriptions and search interface: 

    <https://bugs.freebsd.org/bugzilla/describekeywords.cgi>