Re: Grendel - Linux file system testing - long post

[Kalum / Grendel <kalum delrom ro>]

On Tue, 1 Oct 2002,  Mark Knecht commented thusly,

> Grendel,
>    We can take this offline if it's going to use too much bandwidth
> rh-install bandwidth or bore other people. I think others will find some of
> this helpful, but it's up to them. (I know you and I will!) Thanks in
> advance.

No problem, anyway its better I think keeping it on this forum as anyone
can chip in with his/hers advice.

>    Following on from the previous conversation, I set up a machine today
> with a fairly complicated, but interesting, set of disk partitions for the
> purpose of playing with some of these different file system options, ext2,
> ext3, reiserfs and XFS. I will be using Benno's latencytest scripts, plus a
> modified version that uses alsa and jack, as this is what we are
> standardizing on in the Ardour Users group.


So in summary your current system is mounted as
/dev/hda5 = windoze
/dev/hda6 = / (root)
/dev/hda7 = swap


I have stripped a few of the entries....of the fdisk command

>    Device Boot    Start       End    Blocks   Id  System
> /dev/hda4          2308      2434   1020127+  83  Linux
> /dev/hda8           825      1002   1429753+  83  Linux
> /dev/hda9          1003      1257   2048256   83  Linux
> /dev/hda10         1258      1542   2289231   83  Linux
>
>
>    What I'd like to do is mount each of the new Linux partitions (hda4,
> hda8, hda9 & hda10 - currently all ext2), check that they are all working,
> and then convert each of them to a different file system for testing. This
> keeps all the file systems on the same drive and HD controller.
>
>    Can you give me some pointers on how to go about this? I assume I
> probably just make some mount points and then create some entries in fstab
> to mount them as ext2. Is this correct? I want to run latencytest on each
> partition to make sure I look for any differences across the drive itself.

Yes, as they are ext2 you can create the mount points in /mnt, and then
add the entries to /etc/fstab to point to the mount points you have
created. Or you can mount them manually.

here is a example from my /etc/fstab, my /dev/hda5 is a XFS partition.

/dev/hda5       /mnt/morespace  xfs

So now say you create a mount point  as /mnt/testpart1, and you wish to
mount /dev/hda4 then your fstab file should have the following line

/dev/hda4       /mnt/testpart1  ext2

as your /dev/hda4 is a ext2 filesystem you specify it as ext2.anyway you
probably know the above.

>    Following that, how to I convert them to the new file systems? Are there
> programs for 'formatting' them into reiserfs or XFS? How do I turn on
> journaling to get ext2 to act as ext3.

Unfortuantely there are no "converting programs" to my knowledge, which
means that basically you have 1 option.

1. Copy the data to a spare partition preserving attributes etc, Make the
new partition, which would delete the data on the ext2 in that partition
, and copy back the data to it.


Example, you have just tested /dev/hda4 as ext2 and want to convert it to
reiserfs,

well copy the current files from /dev/hda4 (you can use the cp command or
the tarball method) to some location on another partition, say your /
partition.

Now unmount it
umount /dev/hda4

mow we create the reiserfs
Just run mkreiserfs /dev/hda4 which will delete the ext2 file system on
it...

now you have a blank reiserfs /dev/hda4, so we will remount it..(you will
have to change you relevant fstab entry from ext2 to reiserfs), or
manually mount it with the "-t reiserfs" option

now you can copy back the data which you copied to another partition, and
you are back with a reiserfs partition.


Its the same for XFS.

some usefule links
<http://www1.freeos.com/articles/3933/>

About reiserfs...

<http://oss.sgi.com/projects/xfs/>
<http://oss.sgi.com/projects/xfs/faq.html>

You can find patches for basically all the linus kernels and a few of the
ac kernels at the xfs site.


Best Wishes,
Grendel


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