> -----Original Message----- > From: Gregory Farnum [mailto:greg@xxxxxxxxxxx] > Sent: Wednesday, April 08, 2015 6:26 PM > To: Deneau, Tom > Cc: ceph-devel > Subject: Re: ms_crc_data false > > On Wed, Apr 8, 2015 at 3:38 PM, Deneau, Tom <tom.deneau@xxxxxxx> wrote: > > With 0.93, I tried > > ceph tell 'osd.*' injectargs '--ms_crc_data=false' '-- > ms_crc_header=false' > > > > and saw the changes reflected in ceph admin-daemon > > > > But having done that, perf top still shows time being spent in crc32 > routines. > > Is there some other parameter that needs changing? > > You can change this config value, but unfortunately it won't have any effect > on a running daemon. You'll need to specify it in a config and restart. > -Greg Thanks, Greg. Here are some observations on my single node system after changing the ceph.conf and restarting all daemons... loop rados bench seq reading 4M objects (1 thread) (dropping caches before each invocation) * BW went up with ms crc xxx = false * but still see signficant crc32 line attributed to ceph-osd * no writes happening * note: with ms crc xxx = true, there were 2 crc32 lines in perf top, the 2nd one attributed to librados, that one is gone with ms crc xxx = false loop rados get single largeObject (1.6G) /dev/null (dropping caches before each invocation) * no change in BW from ms crc xxx = true * no crc32 line in perf top * whereas with ms crc xxx=true there were 2 lines one for ceph-osd, one for librados -- Tom Deneau ��.n��������+%������w��{.n����z��u���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
