Subject: Re: resize_ffs (was: Re: JFS)
To: Brian Chase <vaxzilla@jarai.org>
From: Bill Studenmund <wrstuden@netbsd.org>
List: tech-kern
Date: 02/26/2003 09:25:52
On Tue, 25 Feb 2003, Brian Chase wrote:

> On Tue, 25 Feb 2003, Jason R Thorpe wrote:
> > On Tue, Feb 25, 2003 at 05:26:24PM +0100, Jochen Kunz wrote:
>
> >  > I suspect that the FS has to be unmounted to be resized?
> >
> > Yah, I think that applies with the FreeBSD growfs, too.
>
> But it doesn't apply to JFS under AIX or XFS under IRIX.  I must admit,
> I found being able to grow both of those, live, rather handy on a couple
> of servers I've managed.  In the case of XFS under IRIX, the xfs_growfs
> man page states that "the filesytem must be mounted to be grown."
> I can't imagine why that must be the case.

I too have found growing live file systems really nice.

I think how AIX does it is they tune the file system parameters so that
the cylinder group size is the same as the PP size (Physical Partition, LV
allocation unit, 4 MB on the boxes I ran). That way growing is just adding
a whole cylinder group.

As others have said, file system being mounted means that the journal can
be used to protect the changes to the file system. I don't know if there
actually is an fsck_xfs, so using the journal is important. :-)

Take care,

Bill