Date: Thu, 30 Nov 2006 11:40:54 -0800 From: Derrick MacPherson <dmacpher@vfs.com> To: Chuck Swiger <cswiger@mac.com> Cc: freebsd-questions@freebsd.org Subject: RE: degraded RAID performance after OS upgrade, and drives added. Message-ID: <20061130194051.4147C43D6B@mx1.FreeBSD.org>
next in thread | raw e-mail | index | archive | help
That seems like a pretty crazy drop in performance, more than one would exp= ect. The machine is busy but not busy enough to warrant this.. Imo.. Is the= re a way to test to confirm? -----Original Message----- From: "Chuck Swiger" <cswiger@mac.com> To: "Derrick MacPherson" <dmacpher@vfs.com> Cc: freebsd-questions@freebsd.org Sent: 11/30/06 10:39 Subject: Re: degraded RAID performance after OS upgrade, and drives added. On Nov 29, 2006, at 6:18 PM, Derrick MacPherson wrote: > We updated to 6.1 this weekend and added 3 300gb drives to the =20 > external raid cabinet, they were to go on a seprate controller but =20 > the server happens to have a few other boxes on top making it =20 > impossible at that time, so we put the 3x300 (RAID5) , upgraded =20 > the OS and performance is very poor. When I run systat I see =20 > upward of 300 tps on the problematic array (da2) and under systat -=20 > vmstat : It's normal for RAID-5 to perform worse than a single drive-- and =20 sometimes it performs much worse, as in nearly an order of magnitude =20 slower, for the case of very small writes. If you value performance, =20 choose another RAID level like RAID-0, RAID-1, or RAID-10. --=20 -Chuck
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20061130194051.4147C43D6B>