From: Cameron Harr <charr@fusionio.com>
To: landman@scalableinformatics.com
Cc: general@lists.openfabrics.org, linux-scsi <linux-scsi@vger.kernel.org>
Subject: Re: [ofa-general] iSer and Direct IO
Date: Thu, 15 May 2008 09:50:28 -0600 [thread overview]
Message-ID: <482C5BC4.6090301@fusionio.com> (raw)
In-Reply-To: <482C55E2.8060905@scalableinformatics.com>
Joe Landman wrote:
> This is only 8 GB of IO. It is possible that (despite dio) you are
> caching. Make the IO much larger than RAM. Use a count of 128m or so.
This is going to sound dumb, but I thought I had 4 GB of RAM and thus
intentionally used a file size 2x my physical RAM. As it turns out, I
have 32GB of RAM on the box (4G usually shows up as 38.... and I just
saw the 3). Anyway, with a 64GB file the numbers are looking more
accurate (and even low):
393.3 MB/s
> We have found dd to be quite trustworthy with [oi]flag=direct.
I like it too. At any rate, I'm going to need to do some new testing to
avoid the ram size (might just set a mem limit on the boot line).
There's still a bit of a discrepancy between IOP performance with iSer
and srpt. Has anyone else done comparisons with the two? I think Erez
was hoping to get some numbers before too long.
Cameron
next prev parent reply other threads:[~2008-05-15 15:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <482B7FE4.9070502@fusionio.com>
2008-05-15 11:23 ` [ofa-general] iSer and Direct IO Eli Dorfman
2008-05-15 15:11 ` Cameron Harr
2008-05-15 15:25 ` Joe Landman
2008-05-15 15:50 ` Cameron Harr [this message]
2008-05-15 15:58 ` Joe Landman
2008-05-15 15:25 ` Cameron Harr
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