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katanacb
09-Mar-2012, 19:33
Hi there,

I think that I've found a regression in SLES 11 SP2 (compared to SLES 11 SP1).

With SLES 11 SP1, it was possible to install full ext4 support (full meaning that after installation was complete, you could install ext4 kmod's and have full read / write access to an ext4 filesystem).

As far as I can tell, this is NOT possible with SP2. -- it will ONLY mount ext4 volumes as 'read only'. It doesn't matter what mount options you pass (I specifically tried 'rw'), it's still mounted as read-only. This is causing major problems
for me as I try and upgrade my server(s) internally that are running SLES11 SP1 -- since the ext4 filesystems are read-only, and I have to copy
everything off, rebuild the filesystems as either ext3 or xfs, then copy everything back, causing extended downtimes for upgrades (and some of these filesystems aren't small -- they are upwards of 1TB!).

I've also run into this as I try to upgrade openSUSE systems to SLED ... specifically this is a problem when /home is created as ext4 (the default in openSUSE).

Am I missing something? Is there some file / option that I need to change or pass to alter this behavior? I still can't believe that SuSE doesn't officially support ext4 :-/

KBOYLE
09-Mar-2012, 20:34
katanacb wrote:

> Am I missing something?

See the Release Notes for SUSE Linux Enterprise Server 11 Service Pack
2.

http://www.novell.com/linux/releasenotes/x86_64/SUSE-SLES/11-SP2/#fate-311111


10.9. Read-only Support for the ext4 File System for Migration Purposes

To facilitate the migration of an ext4 file system to another,
supported file system, the SLE 11 SP2 kernel now contains a fully
supported ext4 file system module, which provides solely read-only
access to the file system.

If read-write access to an ext4 file system is still required, you may
install the ext4-writeable KMP (kernel module package). This package
contains a kernel module that provides read-write access to an ext4
file system. Be aware, that this kernel module is unsupported.

ext4 is not supported for the installation of the SUSE Linux Enterprise
operating system files

With SUSE Linux Enterprise 11 SP2 we support offline migration from
ext4 to the supported btrfs filesystem.

--
Kevin Boyle - Knowledge Partner
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katanacb
09-Mar-2012, 22:14
Yes, I saw that in the release notes, but that is changed (reduced) functionality between SP1 and SP2. Is there any way other than recompiling the kernel to get rw access to ext4?

KBOYLE
10-Mar-2012, 04:58
katanacb wrote:

> Is there any way other than
> recompiling the kernel to get rw access to ext4?

I don't know if a recompile is needed or if you just have to install
the package. Someone else may be able to offer an opinion.

Again, according to the Release notes:


> If read-write access to an ext4 file system is still required, you may
> install the ext4-writeable KMP (kernel module package). This package
> contains a kernel module that provides read-write access to an ext4
> file system. Be aware, that *this kernel module is unsupported*.

You may want to consider btrfs.

> With SUSE Linux Enterprise 11 SP2 we support offline migration from
> ext4 to the *supported btrfs filesystem*.


--
Kevin Boyle - Knowledge Partner
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show your appreciation and click on the star below...

katanacb
11-Mar-2012, 05:52
Yeah, I saw that in the release notes as well, I've looked EVERYWHERE for that kernel module and I can't seem to find it. Looked on the server CD, source CD, SLED CD, and the SDK CD.

a 'zypper search' command for that package / module doesn't turn anything up, either. I'm on x86_64. Has anyone else out there been able to find this package?

Magic31
12-Mar-2012, 21:58
Yeah, I saw that in the release notes as well, I've looked EVERYWHERE for that kernel module and I can't seem to find it. Looked on the server CD, source CD, SLED CD, and the SDK CD.

a 'zypper search' command for that package / module doesn't turn anything up, either. I'm on x86_64. Has anyone else out there been able to find this package?

I have not checked... but is your server registered to NCC (so you can also see packages in the online repositories?).

Could be you can only install the package through the online repositories.

-Willem

KBOYLE
13-Mar-2012, 03:49
katanacb wrote:

> I've looked EVERYWHERE
> for that kernel module and I can't seem to find it.

I have asked the SUSE folks and I'll update the thread when I learn
something.

--
Kevin Boyle - Knowledge Partner
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show your appreciation and click on the star below...

Magic31
20-Mar-2012, 12:40
I have not checked... but is your server registered to NCC (so you can also see packages in the online repositories?).

Could be you can only install the package through the online repositories.

-Willem

As an update.. The package is there, but to see it you must:

1) Register the SLES server against NCC as to get the online repositories
2) After having registered, enable the SLES-Extra repo using YaST's Software Repositories tool, which is there but disabled by default.

Then you can install the ext4 module... which is, as stated before, unsupported and not recommended for extended/production uses.

Hope that helps,
Willem