1) iotop did not show any significant io, just maybe 30k/second of drbd traffic.
2) okay. I've never done that before. I'll give it a shot. 3) I'm not sure what I'm looking at there. -- Eric Robinson > -----Original Message----- > From: Ulrich Windl [mailto:ulrich.wi...@rz.uni-regensburg.de] > Sent: Tuesday, August 01, 2017 11:28 PM > To: users@clusterlabs.org > Subject: [ClusterLabs] Antw: DRBD and SSD TRIM - Slow! > > Hi! > > I know little about trim operations, but you could try one of these: > > 1) iotop to see whether some I/O is done during trimming (assuming > trimming itself is not considered to be I/O) > > 2) Try blocktrace on the affected devices to see what's going on. It's hard to > set up and to extract the info you are looking for, but it provides deep > insights > > 3) Watch /sys/block/$BDEV/stat for performance statistics. I don't know how > well DRBD supports these, however (e.g. MDRAID shows no wait times and > no busy operations, while a multipath map has it all). > > Regards, > Ulrich > > >>> Eric Robinson <eric.robin...@psmnv.com> schrieb am 02.08.2017 um > >>> 07:09 in > Nachricht > <DM5PR03MB27297014DF96DC01FE849A63FAB00@DM5PR03MB2729.nampr > d03.prod.outlook.com> > > > Does anyone know why trimming a filesystem mounted on a DRBD volume > > takes so long? I mean like three days to trim a 1.2TB filesystem. > > > > Here are some pertinent details: > > > > OS: SLES 12 SP2 > > Kernel: 4.4.74-92.29 > > Drives: 6 x Samsung SSD 840 Pro 512GB > > RAID: 0 (mdraid) > > DRBD: 9.0.8 > > Protocol: C > > Network: Gigabit > > Utilization: 10% > > Latency: < 1ms > > Loss: 0% > > Iperf test: 900 mbits/sec > > > > When I write to a non-DRBD partition, I get 400MB/sec (bypassing caches). > > When I trim a non-DRBD partition, it completes fast. > > When I write to a DRBD volume, I get 80MB/sec. > > > > When I trim a DRBD volume, it takes bloody ages! > > > > -- > > Eric Robinson > > > > > > _______________________________________________ > Users mailing list: Users@clusterlabs.org > http://lists.clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org Getting started: > http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org