Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Sat, Jan 29, 2011 at 12:48, Joseph Hauptmann <joseph.hauptmann at digiconcept.net> wrote: > Am 29.01.2011 00:48, schrieb J. Ryan Earl: >> >> On Fri, Jan 28, 2011 at 1:44 PM, Joseph >> Hauptmann<joseph at digiconcept.net>wrote: >> >>> Yes, I did try that. Doesn't make much of a (speed) difference. >>> >>> It seems, that the problem is less that rm gets stuck for good, but that >>> it >>> takes really long breaks (about 20 sec.) while deleting - during those >>> breaks the whole partition is stuck and iostat reports 100% utilization >>> compared to ~95% while actually deleting files. >>> >> What does I/O state report on the request queue? What's the average >> length? >> What's the avereage I/O request latency? I suspect they are high. >> >> > not really, even when the DRBD device blocks I/O-access completley for a few > seconds. > >>> The filesystem on resource 0 is ext3 with a block size of 4096 and lies >>> on >>> a SW-RAID5 (far from ideal - I know). >>> >> Far from ideal is an understatement. You're actually using the worst >> possible RAID configuration: RAID stripe parity without a write cache. >> The >> performance you see will quickly become asymptotically bound by the >> performance a single spindle in your RAID group. You're running internal >> metadata (like a journal) on DRBD, and you're getting double small FUA >> writes from the filesystem journal in addition to DRBD barriers. >> >> Turn off ext3 journalling. Turn off DRBD barriers. Run your maintenance >> to >> remove the files. Turn them both back on. >> >> -JR >> > Disconnecting the peer was the first thing I did. What really bugs me, is > that deleting the same kind of files on an ext3 lvm that lies next to the > drbd resource on the same md device takes about a minute for 100k files - > without blocking access. The fastest solution is to format the filesystem, but this is not always possible. If you can remove al files in the directory, the fastest I/O friendly command could be: ionice -c 3 rm -rf /directory -- Marcelo "¿No será acaso que ésta vida moderna está teniendo más de moderna que de vida?" (Mafalda)