Re: how to query filesystem type?

[Jim Edwards]

On Tue, Jul 5, 2011 at 10:11 AM, Rob Latham <address@hidden> wrote:

> On Tue, Jul 05, 2011 at 09:41:37AM -0600, Jim Edwards wrote:
> > I would like to have autoconf determine if a target filesystem is gpfs or
> > lustre - are there existing tools to do this?
> >
> > If not is anyone aware of a shell command that would provide this?
>
> i'd just like to point out that in general there's no guarantee that
> the file system you detect at configure time will be the one you
> access during run time.
>

This is true, but the working directory is an input to the script and I'm
using this to determine and set
mpi-io filesystem hints - as far as I know it doesn't hurt much if I get
them wrong - the hints will be ignored and
nothing will fail.



>
> the 'stat -f /path/to/file_system' command can give you the
> information you want:
>
> % stat -c %T -f /
> ext2/ext3
>
>
Running this on /tmp/work/$USER on jaguarpf gives

UNKNOWN (0xbd00bd0)

I suppose you could key on the magic number, but that doesn't seem very
robust.




> If you use the system call statfs(2) you can determine the fs type at
> runtime.  Nowadays it's even reasonably (but not entirely) portable:
>
> struct statfs has a f_fsid member.  The magic number for Lustre is "#define
> LL_SUPER_MAGIC 0x0BD00BD0" (defined in lustre_user.h).  The magic number
> for
> GPFS is ...  0x47504653 I guess?
>

I get this result from a bluegene linux front end, but not from AIX.


>