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From: Vadim Rozenfeld <vrozenfe@redhat.com>
To: Peter Lieven <pl@dlhnet.de>
Cc: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	ronnie sahlberg <ronniesahlberg@gmail.com>
Subject: Re: [Qemu-devel] Windows and I/O size
Date: Tue, 8 Jan 2013 11:29:59 +0200	[thread overview]
Message-ID: <201301081129.59373.vrozenfe@redhat.com> (raw)
In-Reply-To: <33BC9CFA-F412-4AD4-A06F-132B29EAF1C2@dlhnet.de>

On Tuesday, January 08, 2013 10:53:44 AM Peter Lieven wrote:
> Am 08.01.2013 um 09:50 schrieb Vadim Rozenfeld <vrozenfe@redhat.com>:
> > On Tuesday, January 08, 2013 10:16:48 AM Peter Lieven wrote:
> >> Hi all,
> >> 
> >> I came across the fact that Windows seems to requests greater 64KB into
> >> pieces leading to a lot of IOPs on the storage side.
> >> 
> >> Can anyone imagine of a way to merge them before sending them to e.g. an
> >> iSCSI Storage? 64KB I/O Size is not optimal when e.g. large sequential
> >> operations with an iSCSI target.
> >> 
> >> Thank you,
> >> Peter
> > 
> > Hi Peter.
> > Is it viostor? Which version? The most recent one is able to handle 256K
> > blocks.
> 
> Not the recent. I will try 0.1.49 now.
> 
> 256KB is still not that much but definitely better than 64KB. are this
> windows limits?

not exactly. it came from the driver itself. actually, with indirect buffer 
support in virtio the sky is the limit.  

> 
> I have found docs in the net that windows splits up everything into 64kB
> requests. Is this info old?
> 
> thank you,
> Peter
> 
> > Best regards,
> > Vadim.

  reply	other threads:[~2013-01-08  9:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-08  8:16 [Qemu-devel] Windows and I/O size Peter Lieven
2013-01-08  8:50 ` Vadim Rozenfeld
2013-01-08  8:53   ` Peter Lieven
2013-01-08  9:29     ` Vadim Rozenfeld [this message]
2013-01-08  9:47       ` Peter Lieven
2013-01-08 10:15         ` Vadim Rozenfeld
2013-01-08 10:09       ` Peter Lieven
2013-01-08 10:21         ` Vadim Rozenfeld

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