I tried to repair the db by removing the shared locks (/var/lib/rpm/__db.00?)
and running rpmdb --rebuilddb

so far that's been running for ~45 minutes. strace shows a long series of
pread() and pwrite(), as I'd think it should, but the time seems quite excessive
(this on an Athlon 1700+, 512 megs RAM)

It eventually finished but with a (harmless?) error:

[cricker@winsucks rpm]$ sudo rpmdb --rebuilddb
error: db4 error(16) from dbenv->remove: Device or resource busy
[cricker@winsucks rpm]$ 

Yes, harmless, but let's backup.

A --rebuilddb should finish in minutes, maybe 10 if
you got a gazillion packages. Add -vv to get feedback,
compare your slow machine with some other.

FYI: stale locks can be displayed by doing
    cd /var/lib/rpm
    /usr/lib/rpm/rpmdb_stat -CA
See the db4-utils doco for dbstat, rpmdb_stat is exactly that.

And you might try rpm-4.2 all-but-final (and errata expected)
from ftp://ftp.rpm.org/pub/rpm/test-{4.2,4.1.1}

So how does the speed of --rebuilddb -vv compare with some
other machine?

This time when I did the 

rpmdb --rebuild -vv

it only took about 12 minutes on this same system (it's an everything install +
some local RPMs, so I'd expect it to take a while)

Here's a data point, --rebuilddb -vv, 960 packages, 600MHz dual SMP, SCSI:

88.55user 10.97system 1:58.77elapsed 83%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (1344major+35058minor)pagefaults 0swaps

12 minutes still seemes excessive to me. what's the difference?

With 1400 packages, I'm seeing

real    15m26.431s
user    1m4.000s
sys     0m16.890s

now on this system.

(The rpm-hanging-during-install thing is related to 87747, right?)

Anyway, on my system (ASUS P2B-DS, 2x P3-800MHz, 1Gb PC-100 ECC RAM, / on an IBM
DRVS09V [U2W-LVD SCSI, 7200rpm]), I ran "rpm -vv --rebuilddb", let it finish
(approx 15 min.), then ran it again:

   # script
   # time rpm -vv --rebuilddb

and I got this:
   real    12m22.903s
   user    2m23.610s
   sys     0m40.620s


I was replying to some email while running it (via kmail) but otherwise the
system was essentially idle.  The disk sure took a beating, though - most of the
time was spent waiting for I/O, based on the numbers from time(1).


FYI:
   # rpm -qa | wc-l
   # time rpm -qa | wc -l
      1430
   real    0m17.496s
   user    0m16.380s
   sys     0m0.710s

**Seventeen seconds** to open a db4 file, iterate through each key, print it,
and close the file seems excessive on this hardware.

-Adam Thompson
 athompso@athompso.net

Not when you realize that header-only signatures/digests are verified
for each header read. Add --nodigest --nosignature to disable.

Meanwhile hangs come from multiple sources, assuming that 2 bugs
that include the word "hang" is futile. Please open a different
bug.

Meanwhile 12-15 minutes for --rebuilddb is larger than I would
expect, but is far less than 45 minutes. I still do not understand
what caused 45 minutes.

Forget --rebuilddb, is the hang fixed or not?!

zaitcev@redhat.com, did you try the rpm builds at
ftp://ftp.rpm.org/pub/rpm/test-4.2/?

I have a fresh RH9 load and I still got the same old "hang" as in 8.0.  Had to
kill and delete the locks to get going again.

Pete, I haven't had it hang again, now that I'm using the final glibc errata
(glibc-2.3.2-27.9)

I'm pretty sure this problem is fixed in rpm-4.2-1.
Reopen if not.