Hello Greg,
Thursday, February 12, 2009, 8:24:38 PM, you wrote:
GM> well, since the write cache flush command is disabled, I would like this
GM> to happen as early as practically possible in the bootup process, as ZFS
GM> will not be issuing the cache flush commands to the disks.
GM> I'm not rea
well, since the write cache flush command is disabled, I would like this
to happen as early as practically possible in the bootup process, as ZFS
will not be issuing the cache flush commands to the disks.
I'm not really sure what happens in the case where the write flush
command is disabled, s
On Thu, Feb 12, 2009 at 10:33:40AM -0500, Greg Mason wrote:
> What I'm looking for is a faster way to do this than format -e -d
> -f
Are you sure thar write cache is back on after restart?
Yes, I've checked with format -e, on each drive.
When disabling the write cache with format, it also gives a warning
stating this is the case.
What I'm looking for is a faster way to do this than format -e -d
-f
We use several X4540's over here as well, what type of workload do you
have, and how much performance increase did you see by disabling the
write caches?
We see the difference between our tests completing in around 2.5 minutes
(with write caches) to around a minute an and a half without them,
On Wed, Feb 11, 2009 at 2:13 PM, Greg Mason wrote:
> We're using some X4540s, with OpenSolaris 2008.11.
>
> According to my testing, to optimize our systems for our specific workload,
> I've determined that we get the best performance with the write cache
> disabled on every disk, and with zfs:zfs
Hello Greg,
Wednesday, February 11, 2009, 10:13:39 PM, you wrote:
GM> We're using some X4540s, with OpenSolaris 2008.11.
GM> According to my testing, to optimize our systems for our specific
GM> workload, I've determined that we get the best performance with the
GM> write cache disabled on eve
> so, basically, my question is: Is there a way to quickly or permanently
> disable the write cache on every disk in an X4540?
Hmmm... the only idea I have is to see how format(1M) does it and
steal the code to write a small disable-cache tool. :-)
Have a look at uscsi(7I) and specifically the ca
We're using some X4540s, with OpenSolaris 2008.11.
According to my testing, to optimize our systems for our specific
workload, I've determined that we get the best performance with the
write cache disabled on every disk, and with zfs:zfs_nocacheflush=1 set
in /etc/system.
The only issue is s
