>> Description of problem: libblkid has recently been patch to improve performance when facing a lot of device-mapper devices : bz672985 - blkid runs very slow with many dm devices and a large blkid.tab file Without this patch, blkid loops on ioctl'ing device-mapper for hours. Dump has static compilation against liblkid library. Extract of compiling dump from source RPM : [...] checking for blkid/blkid.h... yes checking for blkid_get_devname in -lblkid... yes [...] gcc -static -o dump [...] -lblkid [...] [...] It should simply be recompiled to get the patched library. => With a simple recompilation of the dump RPM with the current libblkid (e2fsprogs), we have gone from 33 minutes down to 9 seconds for dumping a small file. Version-Release number of selected component (if applicable): any >> How reproducible: 100%, but you need a proper environment to reproduce the issue (apparently : boot on SAN with many multipath is the most affected). >> Steps to Reproduce: 1. get a boot on SAN machine, with ~100 multipath devices 2. dump 3. wait >> Actual results: wait, again and again. stracing, you will see a huge number of ioctl to device-mapper. >> Expected results: faster dumping >> Additional info: :-)
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Previously, dump was linked against the libblkid library, which processed many device-mapper devices inefficiently. With this update, dump has been rebuilt against an updated version of the libblkid library, and it is now able to process many device-mapper devices efficiently.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2011-1502.html