[CentOS] compare zfs xfs and jfs o

Sun Aug 5 22:18:45 UTC 2012
Joerg Schilling <Joerg.Schilling at fokus.fraunhofer.de>

John R Pierce <pierce at hogranch.com> wrote:

> On 08/05/12 3:06 AM, Joerg Schilling wrote:
> > Your claim is aproximately correct for NFSv2 (1988) but wrong for other NFS
> > versions.
> The server was using NFS V3/V4 in CentOS 6.2 earlier this year, and 
> various clients, including Solaris 10.   The problems were reported from 
> our overseas manufacturing operations so I only got them 3rd hand, and 
> don't know all the specifics.   In my lab I had only shared the root of 
> the file system as thats the model I use, but apparently operations 
> likes to have lots of different shares, MS Windows style.   This was a 
> 'stop production' kind of error, so the most expedient fix was to 
> manually specify the export ID.

If you suffer from bugs in Linux filesystem implementations, you should make a 
bug report against the related code. Only a bug report ans a willing maintainer 
can help you.

The problem you describe does not exist on Solaris nor on other systems with 
bug-free NFS and I know why I try to avoid Linux when NFS is important. It is a 
pity that after many years, there are still NFS problems in Linux.


-	NFSv2 (from 1988) allows 32 Bytes for a NFS file handle

-	NFSv3 (from 1990) allows 64 Bytes for a NFS file handle

-	NFSv4 (from 2004) has no hard limit here

With the 32 byte file handle, there are still 12 bytes (including a 2 byte 
length indicator) for the file id in the file handle.

If your filesystem could use 44 and more bytes in the case you describe, there 
is no problem - except when the code is not OK.

It is of course nice to still support SunOS-4.0 clients, but in case that the 
client supports NFSv3 or newer, why not use longer file id's?


 EMail:joerg at schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
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