I don't necessarily think there's anything wrong with using drbd or running it over gigabit ethernet. If you stop all I/O to the lustre filesystem, what does an hdparm -t show on the sdc and drbd devices? Do you have any performance numbers for the drbd or underlying raid devices?
On Jan 24, 2010, at 11:17 PM, Lex wrote: > Thank you for your fast reply, Aaron > > I'm using Giga Ethernet to synchronize data between to our fail-over node. Is > there something wrong ? Tell me, please > > On Mon, Jan 25, 2010 at 10:35 AM, Aaron Knister <[email protected]> > wrote: > My best guess (and please correct me if I'm wrong) is that those messages are > because the underlying block devices are slow to respond to i/o requests. It > looks like you're using DRBD. What's your interconnect? > > On Jan 24, 2010, at 9:42 PM, Lex wrote: > >> Hi list >> >> I have one OSS with hadware info like this : >> >> CPU Intel(R) xeon E5420 2.5 Ghz >> Chipset intel 5000P >> 8GB RAM >> >> With this OSS, we using 2 RAID-5 arrays as OSTs ( each has 4 x 1.5 TB hard >> drive with RAID controller adaptec 5805 ) >> >> I worked quite smooth before, but, about 2 weeks ago, in /var/log/messages, >> i saw many warning ( i thought so) like this: >> >> Jan 25 08:41:23 OST6 kernel: Lustre: >> 9587:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 35s >> Jan 25 08:41:34 OST6 kernel: Lustre: >> 9608:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 41s >> Jan 25 08:41:34 OST6 kernel: Lustre: >> 9608:0:(filter_io_26.c:706:filter_commitrw_write()) Skipped 2 previous >> similar messages >> Jan 25 08:41:35 OST6 kernel: Lustre: >> 9645:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 43s >> Jan 25 08:58:10 OST6 kernel: Lustre: >> 9646:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 31s >> Jan 25 08:59:39 OST6 kernel: Lustre: >> 9609:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 30s >> Jan 25 09:01:05 OST6 kernel: Lustre: >> 9587:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 33s >> Jan 25 09:03:23 OST6 kernel: Lustre: >> 9633:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 32s >> Jan 25 09:11:25 OST6 kernel: Lustre: >> 9585:0:(filter_io_26.c:706:filter_commitrw_write()) lustre-OST0006: slow >> direct_io 36s >> >> I googled around and found that it's because a problem with oss_num_threads >> and even though brought it down to 64 ( followed by the function i found in >> the 1.8 manual: thread_number = RAM * CPU core / 128 MB, its value is 256 ) >> >> options ost oss_num_threads=64 >> >> It still didn't help. >> >> I thought it was only the harmless warning but maybe wrong, our performance >> is goes down quite heavily ( it's maybe because of other reason, but for >> now, i am only doubting slow direct_io problem ) >> >> iostat -m 1 1 >> Linux 2.6.18-92.1.17.el5_lustre.1.8.0custom (OST6) 01/25/2010 >> >> avg-cpu: %user %nice %system %iowait %steal %idle >> 0.01 0.02 2.86 25.01 0.00 72.10 >> >> Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn >> sda 1.30 0.01 0.00 11386 3469 >> sdb 1.30 0.01 0.00 11531 3469 >> sdc 131.50 12.40 0.26 11793218 249934 >> sdd 178.46 18.00 0.26 17124065 250334 >> md2 3.33 0.02 0.00 22915 2634 >> md1 0.00 0.00 0.00 0 0 >> md0 0.00 0.00 0.00 0 0 >> drbd3 480.10 12.39 0.26 11789047 249639 >> drbd6 565.85 14.89 0.26 14168452 249211 >> >> >> So, could anyone please tell me whether it's warning impact our system >> performance or not ? and if it does, give me solution or advice to resolve >> it, please >> >> Best regards >> >> >> >> >> >> >> _______________________________________________ >> Lustre-discuss mailing list >> [email protected] >> http://lists.lustre.org/mailman/listinfo/lustre-discuss > >
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