[dm-crypt] md + dm-crypt + lvm2: I/O slows down system, I/O schedule ineffective
Ballarin.Marc at gmx.de
Thu Feb 23 11:57:27 CET 2012
Am 23.02.2012 11:19, schrieb Günter Merz:
> I'm experiencing unresponsiveness and a general system slowdown when I'm unpacking big archives or building a big packages (during builds I'm only using max 2 cores). To counter this, I've been experimenting with nice and ionice. Unfortunately, ionice -c3 before big I/O traffic doesn't seem to make any difference. The responsiveness is still really bad at times.
This sounds like those (more or less) well-known hugepage issues.
You could try "echo madvise >
/sys/kernel/mm/transparent_hugepage/defrag" (or "echo never...") if your
kernel is configured to use transparent hugepages (which most modern
distribution kernels are).
If this is your issue, the bug isn't really caused by dm-crypt, but by
Linux memory management issues and it is completely unrelated to ionice
or io scheduler settings.
More information about the dm-crypt