LSI SATA Raid - slow
I'm building a backup server for a client - straight forward as far as
software goes - samba share for the daily backups to go into. Minimal
install plus sarge.
Hardware is a 2ghz Celeron (P4 type), 256MB ram, and four Seagate 160GB
SATA discs in a RAID-5 on this controller:
000:00:07.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID (rev
Subsystem: LSI Logic / Symbios Logic MegaRAID SATA 150-6 RAID
Flags: bus master, 66Mhz, slow devsel, latency 32, IRQ 11
Memory at ef000000 (32-bit, prefetchable) [size=64K]
Capabilities:  Power Management version 2
The card uses the LSI raid chip for raid, and three Silicon Image 3112a
chips for SATA itself. I have a Sil_3112a card and I know it works as
I copied the data that was on the original RAID set (3 discs) off to a
200gb Seagate PATA disc, and mc reported on the large files 27mb/s
Now, copying stuff back to the RAID set, mc reports a mere 6-7mb/s.
The only thing that struck me as weird is that the controller didn't
take much time to create the raid - less than a minute. Last time I
made a raid (2 10krpm SCSI 74gb discs on an Adaptec card) that took a
couple of hours. It seems like this controller does it in the
background, because I can constantly hear the discs going krr krr krr.
But it's been doing that since friday, and I would have thought it
should be done by now.
Any ideas why I'm getting this? 7mb/s write is not going to be enough
to copy all the data before the next backup starts.