Hello All,
I just installed linux kernel 2.4.12 on some test PowerEdge 2550 boxes,
with a PERC 3/Si Raid card (4x 10krpm scsi u160 disks, 128Mb cache, one
raid5 volume, using domsch/adaptecs aacraid driver).
Previously (using 2.4.2 & 2.4.9) the raid volume had a very disapointing
read spead of around 22 Mb/sec (a single disk is faster!). You can
imagine my suprise when i installed 2.4.12, and the read speed went up
to around 60 Mb / Sec !
I tested this speed increase with hdparm, bonnie+, and various 'real
life' applications, and it truely is a lot, i repeat _a lot_ faster for
me.
I don't know what changed in the block layer between then and now, but
please don't change it back ! ;-)
-- Chris Chabot