Hi, Yesterday I migrated my dual-xeon 4GB RAID1 rrd to a quad-opteron 8GB RAID10 server, in the hope to reduce the load. I am managing 18k RRDs, each being updated randomly every ~10minutes over ssh, which makes roughly 30 file updates/s.
I had many performance problems with the new server, which I was able to manage (=server stays alive) using xfs instead of ext3, raid10 instead of raid5. Underlying disk technology is the same (SCSI 10k drives atatched to LSI 1030 controller), but box brand is different. Graphs speak for themselves. http://swissunix.free.fr/rrd/rrd_perf.png Before: 294% iowait 4.9MB/s read (hardware raid1 hidden to linux) 1.1MB/s write 4.6 loadavg After: 318% iowait 57.9MB/s read (linux raid10 -> values have to be div by 2) 2.3MB/s write 8.9 loadavg tests made with rrdtool 1.2.10 and 1.2.19. Now where the heck do those 57.9/2 = 28.95MB/s READ come from??? I do not understand how the Read IOs were multiplied by a factor of 6!!! _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
