Thread: PostgreSQL and the OCFS2 filesystem

The change log for Kernel Stable Build 2.6.16 indicates that OCFS2 has been integrated into the kernel.

(See http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16  and http://www.linux-watch.com/news/NS3447236466.html).

I've searched the PostgreSQL mail archives for previous discussions of OCFS and OCFS2.  It appears the topic has come up before in various mail lists, including the PostgreSQL General and Administration mail lists. (For example: http://archives.postgresql.org/pgsql-admin/2004-04/msg00101.php).

At that time, there was concern about the OCFS/OCFS2 license (GPL) versus the PostgreSQL license (BSD) and the amount of work required to evaluate PostgreSQL's performance with this file system. 

Some of the discussions took place in the context of raw devices versus filesystems (http://archives.postgresql.org/pgsql-admin/2004-03/msg00376.php).

The discussion in at least two different threads suggested that shared memory was the real issue for PostgreSQL, rather than the filesystem (http://archives.postgresql.org/pgsql-general/2005-08/msg01181.php  and http://archives.postgresql.org/pgsql-general/2006-01/msg01244.php).

Now that OCFS2 is part of the kernel, the licensing issue would seem to have been put to rest.  Does the fact that OCFS2 is now part of the kernel help reduce the size of the work effort required to have a look at the possibility of PostgreSQL using OCFS2?  Is shared memory still the real issue? Any thoughts?

Thanks in advance,

Karen

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"Ploski, Karen L" <Karen.Ploski@UNISYS.com> writes:
> Now that OCFS2 is part of the kernel, the licensing issue would seem to
> have been put to rest.

Exactly how do you think that changes its GPL status?

> Does the fact that OCFS2 is now part of the
> kernel help reduce the size of the work effort required to have a look
> at the possibility of PostgreSQL using OCFS2?  Is shared memory still
> the real issue? Any thoughts?

No, a cluster file system doesn't change a thing for us, even if we were
willing to build in a fundamental dependency on a Linux-only, GPL-only
component.

            regards, tom lane

Martha Stewart called it a Good Thing when Karen.Ploski@UNISYS.com ("Ploski, Karen L") wrote:
> The change log for Kernel Stable Build 2.6.16 indicates that OCFS2 has been integrated into the kernel.
>
> (See http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.16  and
> http://www.linux-watch.com/news/NS3447236466.html).
>
> I've searched the PostgreSQL mail archives for previous discussions
> of OCFS and OCFS2.  It appears the topic has come up before in
> various mail lists, including the PostgreSQL General and
> Administration mail lists. (For example:
> http://archives.postgresql.org/pgsql-admin/2004-04/msg00101.php).
>
> At that time, there was concern about the OCFS/OCFS2 license (GPL)
> versus the PostgreSQL license (BSD) and the amount of work required
> to evaluate PostgreSQL's performance with this file system. 

Well, the license for OCFS/OCFS2 hasn't changed, so that wouldn't
change anything relevant.

It would presumably still require some work to evaluate PostgreSQL
performance on this filesystem, no?

> Now that OCFS2 is part of the kernel, the licensing issue would seem
> to have been put to rest.  Does the fact that OCFS2 is now part of
> the kernel help reduce the size of the work effort required to have
> a look at the possibility of PostgreSQL using OCFS2?  Is shared
> memory still the real issue? Any thoughts?

The license continues to be the GPL, which means it's as incompatible
with the notion of trying to run it on other platforms as ever.

If you want to, you can see about investigating performance of
PostgreSQL on top of this filesystem.  The results are only relevant
on Linux, of course.
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