From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bron Gondwana <brong@fastmail.fm>
Subject: Re: Single disk performance
Date: Tue, 30 Jun 2009 09:17:22 +1000
Message-ID: <20090629231722.GA19561@brong.net>
References: <4A44DB23.5000400@austin.ibm.com> <20090626205659.GD3951@think> <4A458373.4010603@austin.ibm.com> <20090629124149.GF3951@think>
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To: Chris Mason <chris.mason@oracle.com>,
	Steven Pratt <slpratt@austin.ibm.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>
Return-path: <linux-btrfs-owner@vger.kernel.org>
In-Reply-To: <20090629124149.GF3951@think>
List-ID: <linux-btrfs.vger.kernel.org>

On Mon, Jun 29, 2009 at 08:41:49AM -0400, Chris Mason wrote:
> On Fri, Jun 26, 2009 at 09:26:59PM -0500, Steven Pratt wrote:
> > 18:40:32 btrfs2 kernel: [ 4459.870613] sd 0:0:1:0: [sdb] Unhandled error 
> > code
> > Jun 26 18:40:32 btrfs2 kernel: [ 4459.870640] sd 0:0:1:0: [sdb] Result:  
> > hostbyte=DID_ABORT driverbyte=DRIVER_OK
> > Jun 26 18:40:32 btrfs2 kernel: [ 4459.870646] end_request: I/O error,  
> > dev sdb, sector 103359232
> >
> > So still not sure if this is HW, but no other FS has triggered it.
> 
> I'm afraid Btrfs can't do this on its own.  It needs to HW, scsi
> drivers or HW or scsi drivdes ;)
> 
> You could try dd if=/dev/sdb of=/dev/zero bs=512 count=1 skip=103359232
> 
> Hopefully that will fall over without btrfs helping.

Surely of=/dev/null ?  Unless you mean to write to the disk at that block
which would be if=/dev/zero of=/dev/sdb...

Bron.