xfs
[Top] [All Lists]

Re: xfs mount/create options (was: XFS status update for August 2010)

To: xfs@xxxxxxxxxxx
Subject: Re: xfs mount/create options (was: XFS status update for August 2010)
From: Michael Monnerie <michael.monnerie@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 6 Sep 2010 07:49:00 +0200
In-reply-to: <20100905130809.GI705@dastard>
Organization: it-management http://it-management.at
References: <20100902145959.GA27887@xxxxxxxxxxxxx> <20100905104739.GC27623@xxxxxx> <20100905130809.GI705@dastard>
User-agent: KMail/1.12.4 (Linux/2.6.35.4-zmi; KDE/4.3.5; x86_64; ; )
I looked into man mkfs now, which brings up these questions:

On Sonntag, 5. September 2010 Dave Chinner wrote:
>         - relatime,logbufs=8,attr=2,barrier are all defaults.

Why isn't logbsize=256k default, when it's suggested most of the time 
anyway? On machines with 32MiB or more 32k is the default, but most 
machines these days have multi-gigabytes of RAM, so at least for 
RAM>1GiB that could be made default.

>         - largeio only affects stat(2) output if you have
>           sunit/swidth set - unlikely on a laptop drive, and has
>           no effect on unlink performance.
>         - swalloc only affects allocation if sunit/swidth are set
>           and has no effect on unlink performance.

Hm, it seems I don't understand that. I tried now on different servers, 
using
stat -f /disks/db --format '%s %S'
4096 4096

That filesystems were all created with su=64k,swidth=(values 4-8 
depending on RAID). So I retried specifying directly in the mount 
options: sunit=128,swidth=512
and it still reports "4096" for %s - or is %s not the value I should 
look for? Some of the filesystems even have allocsize= specified, still 
always 4096 is given back. Where is my problem?

And while I am at it: Why does "mount" not provide the su=/sw= options 
that we can use to create a filesystem? Would make life easier, as it's 
much easier to read su=64k,sw=7 than sunit=128,swidth=896.

When I defined su/sw on mkfs, is it enough, or would I always have to 
specify sunit/swidth with every mount too?

-- 
mit freundlichen Grüssen,
Michael Monnerie, Ing. BSc

it-management Internet Services
http://proteger.at [gesprochen: Prot-e-schee]
Tel: 0660 / 415 65 31

****** Aktuelles Radiointerview! ******
http://www.it-podcast.at/aktuelle-sendung.html

// Wir haben im Moment zwei Häuser zu verkaufen:
// http://zmi.at/langegg/
// http://zmi.at/haus2009/

Attachment: signature.asc
Description: This is a digitally signed message part.

<Prev in Thread] Current Thread [Next in Thread>