[Thu, 30 Oct 2003 14:10:36 +0100] Ivan Sergio Borgonovo <[EMAIL PROTECTED]> <-- : > Time for my newbiness show. > I used hdparm to have the speed of a single drive... but how to test for > speed of software RAID?
Single drives : # hdparm -Tt /dev/hd[e-h] /dev/hde: Timing buffer-cache reads: 128 MB in 0.18 seconds =691.89 MB/sec Timing buffered disk reads: 64 MB in 1.28 seconds = 50.00 MB/sec /dev/hdf: Timing buffer-cache reads: 128 MB in 0.17 seconds =731.43 MB/sec Timing buffered disk reads: 64 MB in 1.28 seconds = 50.00 MB/sec /dev/hdg: Timing buffer-cache reads: 128 MB in 0.17 seconds =731.43 MB/sec Timing buffered disk reads: 64 MB in 1.27 seconds = 50.20 MB/sec /dev/hdh: Timing buffer-cache reads: 128 MB in 0.18 seconds =711.11 MB/sec Timing buffered disk reads: 64 MB in 1.27 seconds = 50.20 MB/sec My RAID partitions are set this way : /dev/md0 = /dev/hd[e-h]5 /dev/md1 = /dev/hd[e-h]6 /dev/md2 = /dev/hd[e-h]7 /dev/md3 = /dev/hd[e-h]8 /dev/md4 = /dev/hd[e-h]9 Multiple drives : # hdparm -Tt /dev/md[0-4] /dev/md0: Timing buffer-cache reads: 128 MB in 0.17 seconds =731.43 MB/sec Timing buffered disk reads: 64 MB in 0.64 seconds =100.00 MB/sec /dev/md1: Timing buffer-cache reads: 128 MB in 0.17 seconds =752.94 MB/sec Timing buffered disk reads: 64 MB in 0.60 seconds =105.79 MB/sec /dev/md2: Timing buffer-cache reads: 128 MB in 0.17 seconds =731.43 MB/sec Timing buffered disk reads: 64 MB in 0.60 seconds =106.67 MB/sec /dev/md3: Timing buffer-cache reads: 128 MB in 0.17 seconds =752.94 MB/sec Timing buffered disk reads: 64 MB in 0.59 seconds =108.47 MB/sec /dev/md4: Timing buffer-cache reads: 128 MB in 0.17 seconds =752.94 MB/sec Timing buffered disk reads: 64 MB in 0.60 seconds =106.67 MB/sec It looks not as fast as one could expect I think (I remember 157 MB/sec with the 4 same disks attached to my earlier VIA VT8233 controller). I don't know if the stats are really accurate or if the PDC20276 chipset is buggy. Anyway this is much better than single disk's performance. -- Michael Linux: Because rebooting is for adding new hardware. -------------------------------------- Gentoo Linux 1.4 (Intel) Kernel 2.4.20 [SMP,ACPI,RAID] 12281.44 BogoMIPS -- [EMAIL PROTECTED] mailing list
