My original question was:
What's this panic: ufs_putapage: bn == UFS_HOLE mean?
Thanks to
Kevin Sheehan
Glenn Satchell
Steve Phelps
Umesh Vaghela and
Birger A. Wathne
for their help replies.
Kevein Sheehan summarised what it means:
UFS files are allowed to be sparse, which means that if you don't
write to a section, space is not allocated. E.g. if you create
a 0 length file and write byte 0 and byte 1 million, the first
and last blocks are allocated, the ones in between read as zeroes
but have no disk space allocated. Core files are a typical example
of sparse files..
ufs_putapage was asked to put back a page in memory to a file, and
UFS found out that there was no block there, which is clearly a
Bad Thing. Either you have some FS corruption (fsck should find
this) or you need to install patches.
[Kai: I've installed all recommended patches as of March 8. ]
Epilogue:
It seems the swap drive is having problems. Soon after the crash I got
several times scsi bus reset errors for all the disk drives when load was
high. iostat -x 30 gave me around 300ms for svc_t to the swap drive, which
used to be 30ms. I've since moved the swap to elsewhere and it seems stable
after several days.
Kai