Talking w/ someone who had a raid6 of 15 drives on an areca controller, he wondered why he could only get 300MB/s or so out of a streaming buffered write to xfs like so: dd if=/dev/zero of=/mnt/stora
Author: Michael Monnerie <michael.monnerie@xxxxxxxxxxxxxxxxxxx>
Date: Sat, 4 Jul 2009 01:51:19 +0200
Amazeing, more than double speed with a one-liner. Do you have more such lines? ;-) Could this be helpful here also: I've just transfered a copy of a directory from our server to a Linux desktop. Not
If the nr_to_write calculation really yields a value that is too small, shouldn't it be fixed elsewhere? Otherwise it might make sense to make the fudge factor tunable. -- Olaf Weber SGI Phone: +31(0
In theory it should. But given the amazing feedback of the VM people on this I'd rather make sure we do get the full HW bandwith on large arrays instead of sucking badly and not just wait forever.
So how do you feel about making the fudge factor tunable? I don't have a good sense myself of what the value should be, whether the hard-coded 4 is good enough in general. -- Olaf Weber SGI Phone: +3
A tunable means exposing an ABI, which I'd rather not do for a hack like this. If you don't like the number feel free to experiment around with it, SGI should have enough large systems that can be us
I did some quick tests and found some unhappy things ;) On my 5 drive sata array (configured via LVM in a stripeset), dd with O_DIRECT to the block device can stream writes at a healthy 550MB/s. On 2
This is the original thread, it did lead to a few different patches going in, but the nr_to_write change wasn't one of them. http://kerneltrap.org/mailarchive/linux-kernel/2008/10/1/3472704/thread -c
Thanks good pointer. This thread have multiple interesting discussion. 1. making ext4_write_cache_pages() or modifying write_cache_pages() if he says modifying write_cache_pages() is necessary, I'd
On Thu, Jul 09, 2009 at 11:04:32AM +0900, KOSAKI Motohiro wrote: On Tue, Jul 07, 2009 at 07:33:04PM +0900, KOSAKI Motohiro wrote: At least, I agree with Olaf. if you got someone's NAK in past thread