Simon Matter wrote:
I've had a couple of my users' seen DBs, which are skiplist, go south
recently. Since ctl_cyrusdb in 2.2.12 doesn't actually check the seen
databases, I looked around for a recovery utility, but found none. I
tried to use cvt_cyrusdb to convert them from skiplist to skiplist and
skiplist to text, but I got errors every time. I moved the defective
DBs so they could be re-recreated (at least one person was unable to
actually re-mark them messages read). From running 'strings' on the bad
DBs and comparing a flat-file dump of a good DB, it looks like all or at
least most of the data is there--enough that it would be less annoying
than having all messages marked unread. So before I dig into this
myself, has anyone tried to write a utility that recovers, brutally if
necessary, skiplist databases?
We have also seen skiplist corruption in seen databases. I don't have a
recovery tool, but I have been able to manually recover seen db's to the
point of corruption so that at least most of the users mails are in the
correct 'read' state. Typically, you will see errors like:
DBERROR: skiplist recovery /usr/local/imap/user/k/kdelaney.seen: 0D2C
should be ADD or DELETE
If you truncate the file at this point, it should fix the problem, and
the users mail read state will be valid upto the point of corruption.
To do this, convert the hex to decimal (above would be 1372) and use the
dd command:
dd if=kdelaney.seen of=kdelaney.seen.fixed bs=1 count=1372
replace the corrupted .seen file with the fixed one and have user log in
and should be ok.
Seems to work on the couple I have tried it on.
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