Message-Id: <200105111416.f4BEGfP15556@jen.americas.sgi.com>
To: "a. heidenreich" <heid.a@swol.de>
cc: linux-xfs@oss.sgi.com
Subject: Re: xfs 
In-Reply-To: Message from "a. heidenreich" <heid.a@swol.de> 
   of "Thu, 10 May 2001 23:14:27 +0200." <3AFB04B2.D4F75523@swol.de> 
Date: Fri, 11 May 2001 09:16:41 -0500
From: Steve Lord <lord@sgi.com>
Sender: owner-linux-xfs@oss.sgi.com
Precedence: bulk

> hi,
> 
> it seems to me that using the same external logdevice for two different
> xfs filesystems doesn't work! are there any restrictions? (sorry, i
> don't find anything in your man pages or online papers)
> 
> thx in advance.
> 
> andre
> 

To add a second response here - the Irix implementation does not truly
support external logs, Irix volume managers support volumes which have
seperate subvolumes for file data and the log - it looks like a single
device to everything but the volume manager and the filesystem. Since
Linux volume managers have no similar concept this was mapped to explicitly
specifying separate devices on the mkfs and mount command lines.

This however is a totally different implementation from ext3's ability to
share a log device between filesystems. Getting xfs to use a shared
journal device across several filesystem is not a realistic proposition
without major code surgery and breaking compatibility with existing
filesystems.

Steve