-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
Vladimir I. Umnov wrote:
|HW: chipset 875WPE, P4 2.4HT, 3 SATA WD 160JD, 1 ATA Samsung 80Gb. |SW: kernel 2.6.6, libata drivers for PROMISE S150 TX4. |CONFIG: 256K readahead on all drives. | sda1,sdb1,sdc1->RAID0 (md0) | sda2,sdb2,sdc2,hda1->RAID5 (md1) | about 20 partitions on LVM2 with xfs,ext3,reiserfs | chunksize on md0, md1 = 256k - this was optimal with 2.6.0test3 about | year ago. | |Theoretically RAID0 read speed should be nearly read speed of one |drive multiply to number of drives, but I have: |dd if=/dev/sda1 of=/dev/null gives about 44 Mb/s on all drives (but on |sii3112 ide driver with WD 160JD about 55Mb/s and on libata the same |44)
I use my arrays for large video files so large readahead is good.
I use blockdev on the lvms: /sbin/blockdev --setra 4096 /dev/video_vg/video_lv /sbin/blockdev --setra 4096 /dev/video_vg/huge_lv
the md device: /sbin/blockdev --setra 4096 /dev/md0
and the raw devices /sbin/blockdev --setra 4096 /dev/sda /sbin/blockdev --setra 4096 /dev/sdb /sbin/blockdev --setra 4096 /dev/sdc /sbin/blockdev --setra 4096 /dev/sdd /sbin/blockdev --setra 4096 /dev/hdb
HTH
David -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
iD8DBQFBJMz08LvjTle4P1gRAkfpAJ9XA17vexSqmcN0LVFZOx0Dxik/BQCgjMk+ oAslumzTWosxF9WqnDXln3k= =C3uO -----END PGP SIGNATURE-----
- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
