On Tue, 2002-11-05 at 22:06, Seth Mos wrote:
> At 20:50 5-11-2002 +0100, Christophe Zwecker wrote:
> >Hi,
> >
> >I have write cache disabled on the 3ware controller. I copied 300 gb
> >over network, I noticed that every 50mb or so, the controller stalled,
> >didnt accept more data while writing like crazy to disk.
>
> How much ram do you have in this server? Does the stall occur exactly every
> 30 seconds == to time to fill ram?
256 MB, I dont think it reaches 256mb filling when it stalls
>
> Maybe you could investigate Gigabit Ethernet and a cross over cable :-)
> The 3ware controller should easily beat the 3MB/s mark though.
yeah, with write cache enabled its alot faster. its not the network
thats slow, just the machine with the controller refuses to take more
data
>
> What disks are attached, what speed and size, how many, what sort of raid
> config. Does it have a battery cache.
5x 120GB IBM 7200RPM IDE disks, RAID5 on an EVMS/LVM Volume
>
> > After that I tried
> >to turn write cache on, huge more performance. hmm well. I rebooted
>
> Only turn on write caching if the thing has a batter cache to back up the
> ram in case of a power failure.
I dont have batter cache, but am I not safe with an USV , that shutsdown
the machine in case of power failure ?
> >also: Do I have to disable write cache on the drives themselfes too ?
>
> Yes.
uh, are there tools for that ?
>
> >I have another box with an SCSI ICP Controller and RAID5/XFS on it, I
> >quickly disabled write cache there too, had it running for a year with
> >(phew) :-)
>
> If it has a battery cache you are safe.
it doesnt, rebooted like 3 times in one year, nothing happened sofar..
thx for your comments!
--
Christophe Zwecker mail: doc@xxxxxxxxxx
Hamburg, Germany fon: +49 179 3994867
http://www.zwecker.de
"Who is General Failure ? And why is he reading my disk ??"
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