Stuart Glenn wrote:
A little back story: I have a Norco DS-1220, a 12 bay SATA box, it is
connected to eSATA (SiI3124) via PCI-X two drives are straight
connections, then the other two ports go to 5x multipliers within the
box. My needs/hopes for this was using 12 500GB drives and ZFS make a
very large & simple data dump spot on my network for other servers to
rsync to daily & use zfs snapshots for some quick backup & if it
things worked out start trying to save up towards getting a thumper
someday
The trouble is it is too slow to really useable. At times it is fast
enough to be useable, ~ 13MB/s write. However, this last for only a
few minutes. It then just stalls doing nothing. iostat shows 100%
blocking for one of the drives in the pool
I can however use dd to read or write directly to/from the disks all
at the same time with good speed (~30MB/s according to dd)
The test pools I have had are either 2 raidz of 6 drives or 3 raidz of
4 drives. The system is using an Athlon 64 3500+ & 1GB of RAM.
Any suggestions on what I could do to make this useable? More RAM? Too
many drives for ZFS? Any tests to find the real slow down?
I would really like to use ZFS & solaris for this. Linux was able to
use the same hardware using some beta kernel modules for the sata
multipliers & its software raid at an acceptable speed, but I would
like to finally rid my network of linux boxen.
I have similar issues on my home workstation. They started happening
when I put Seagate SATA-II drives with NCQ on a SI3124. I do not
believe this to be an issue with ZFS. I've largely dismissed the issue
as hardware caused, although I may be wrong. This system has had
several problems with SATA-II drives which hardware forums suggest are
issues with the nForce4 chipset and SATA-II.
Anyway, your not alone, but its not a ZFS issue. Its possible a tunable
parameter in the SATA drivers would help. If I find an answer I'll let
you know.
benr.
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