Re: [MiNT] ext3/ext4

[Peter Slegg <p.slegg@scubadivers.co.uk>]

On Tue, 11 May 2010 00:08:05 , Eero Tamminen <oak@helsinkinet.fi> wrote:
> Hi,
>
> On Monday 10 May 2010, Stefan Niestegge wrote:
> > > AFAIK it keeps a journal and so if there is a crash and the system
> > > has to reboot it doesn't have to check the filesystem. Otherwise
> > > it is the same as ext2.
> > >
> > > http://en.wikipedia.org/wiki/Ext3
> > >
> > > I think Ubuntu uses ext3 or possibly ext4 by now
>
> Ext4.  In most things it's faster than Ext3, but it has some design
> issues which require workarounds in programs which make it slower
> than Ext3.
>
> (google for "ext4 atomic renames" for the issue these programs try
> to avoid and how ext4 maintainer thinks that should be done.)
>
>
> > Exactly, and with help of that journal, filesystem errors (that in fact
> > occur with ext3 as well) can be more safe recovered.
> >
> > I just happen to exprience a FS check. Some stuff was bound to
> > lost&found during that,
> > now my MiNT moans about some folders in /etv/var and similar not found.
> >
> > I will have to reinstall. Ext3 most probably would have saved me from
> > that.
> >
> > So, if someone thinks, ext3 could be possible to port for our MiNT
> > system, i vote for it.
>
> They both journal the disk metadata, not the file contents.
>
> I.e. your file system can be fine after crash, but your file contents
> may still be messed if a file write was interrupted.
>
> Journaling also slows things down as (meta) data is written twice, first to
> the journal, then to the disk.  I'm waiting for log based file systems,
> they're the next big thing after journaling file systems.  :-)
>
>
>     - Eero


ext3 would be a nice option though. At least the journalling
mean that the filecheck doesn't have to run after a crash.
I presume it is similar to ext2 with journalling bolted on.

This might be the easiest option for prgression from ext2

Peter