From: Kevin C. <kev...@us...> - 2005-03-30 15:07:08
|
Hi Ken, On Mon March 28 2005 11:30 am, Ken Hwang wrote: > Hi Kevin & Syrius, > > Thank you both Kevin and Syrius. The one line patch did fix the "reference > to NULL" problem. But I found a performance problem after that. With the > patch I could use EVMS to build or activate a RAID-5 without problem. Then > I used "cat /proc/mdstat" to check the resync progress and found the resync > speed was about 1024K/sec. If I used mdadm such as "mdadm --create > --verbose /dev/md4 --level=5 --raid-devices=3 /dev/sda9 /dev/sdb9 > /dev/sdc9" then I could get about 38053K/sec resync speed. I remembered > with the same machine (2.4GHz P4 and Promise TX4 SATA controller) but with > 2.4.27 kernel with libata patch and EVMS 2.3.4 the resync speed was about > 15000K/sec. Is there anyone aware of this? Yeah, this has been pointed out a few times. I think the problem is in the MD driver. It probably doesn't know how to properly adjust the resync speed when an MD device is activated on top of DM devices. We haven't had time yet to fully track down this problem. For now, you should be able to adjust /proc/sys/dev/raid/speed_limit_min to increase your resync speeds. -- Kevin Corry kev...@us... http://www.ibm.com/linux/ltc/ http://evms.sourceforge.net/ |