Discussion:
[OpenAFS-devel] How to know filesystems managed by AFS
Frank Batschulat (Frank Batschulat)
2002-02-27 10:12:56 UTC
Permalink
Hi All,

I often get the problem to find out AFS managed
UFS filesystems, there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.

All that appears is the following entry in /etc/mnttab:
AFS /afs afs dev=100000 1011729826

df gives you:
/afs (AFS ):18000000 blocks 9000000 files

I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.

thx
frankB
Harald Barth
2002-02-27 11:03:16 UTC
Permalink
Post by Frank Batschulat (Frank Batschulat)
I often get the problem to find out AFS managed
UFS filesystems,
Common misinterpretation: It's not an UFS filesystem. It's AFS.
Post by Frank Batschulat (Frank Batschulat)
there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.
Are you talking about kernel panic dumps? The afs kernel module keeps
trace of the servers it's talking to. I guess that a crash dump from
a crashed afs client is only useful in combination with the matching
kernel module source.

The information in the mnttab and vfstab are just to make programs
happy who like to look at those files. The only valid information in
there is the mountpoint (/afs) and the filesystem type (afs).
Post by Frank Batschulat (Frank Batschulat)
I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.
There is no direct relation between the /afs mountpoint and a
underlying filesystem. Where to find its volumes and files is figured
out by afs dynamically depending on the configuration in
/usr/vice/{CellServDB,ThisCell} and the data afs requests from the
fileservers and the volumeservers. The AFS filesystem is worldwide and
replicated. To give you just a glimpse from my laptop: (fs is an AFS
utility)

$ fs where /afs/cs.cmu.edu
File /afs/cs.cmu.edu is on hosts BLUEBERRY.SRV.CS.CMU.EDU PEACH.SRV.CS.CMU.EDU MANGO.SRV.CS.CMU.EDU BANANA.SRV.CS.CMU.EDU
$ fs where /afs/e.kth.se
File /afs/e.kth.se is on hosts elektrien.e.kth.se basalt.e.kth.se pyrit.e.kth.se
$ fs where /afs/athena.mit.edu
File /afs/athena.mit.edu is on hosts HYDRA.MIT.EDU SCYLLA.MIT.EDU CHARYBDIS.MIT.EDU AJAX.MIT.EDU

A good starting point is http://www.openafs.org/. In the left lower
corner you will find the AFSLore Wiki which is part of the effors
to document things better than that they are now.

Harald.
Derrick J Brashear
2002-02-27 20:12:30 UTC
Permalink
Post by Frank Batschulat (Frank Batschulat)
Hi All,
I often get the problem to find out AFS managed
UFS filesystems, there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.
AFS /afs afs dev=100000 1011729826
/afs (AFS ):18000000 blocks 9000000 files
I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.
Do you mean on what filesystem the disk cache lives, or something else?

AFS is a network filesystem, generally, so just like NFS mounted
filesystems, the actual data lives elsewhere; Unless you mean "where is
the disk cache stored" I don't think this question makes sense. If you
mean that, then I have no real suggestions.
Frank Batschulat (Frank Batschulat)
2002-02-27 10:12:56 UTC
Permalink
Hi All,

I often get the problem to find out AFS managed
UFS filesystems, there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.

All that appears is the following entry in /etc/mnttab:
AFS /afs afs dev=100000 1011729826

df gives you:
/afs (AFS ):18000000 blocks 9000000 files

I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.

thx
frankB
Harald Barth
2002-02-27 11:03:16 UTC
Permalink
Post by Frank Batschulat (Frank Batschulat)
I often get the problem to find out AFS managed
UFS filesystems,
Common misinterpretation: It's not an UFS filesystem. It's AFS.
Post by Frank Batschulat (Frank Batschulat)
there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.
Are you talking about kernel panic dumps? The afs kernel module keeps
trace of the servers it's talking to. I guess that a crash dump from
a crashed afs client is only useful in combination with the matching
kernel module source.

The information in the mnttab and vfstab are just to make programs
happy who like to look at those files. The only valid information in
there is the mountpoint (/afs) and the filesystem type (afs).
Post by Frank Batschulat (Frank Batschulat)
I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.
There is no direct relation between the /afs mountpoint and a
underlying filesystem. Where to find its volumes and files is figured
out by afs dynamically depending on the configuration in
/usr/vice/{CellServDB,ThisCell} and the data afs requests from the
fileservers and the volumeservers. The AFS filesystem is worldwide and
replicated. To give you just a glimpse from my laptop: (fs is an AFS
utility)

$ fs where /afs/cs.cmu.edu
File /afs/cs.cmu.edu is on hosts BLUEBERRY.SRV.CS.CMU.EDU PEACH.SRV.CS.CMU.EDU MANGO.SRV.CS.CMU.EDU BANANA.SRV.CS.CMU.EDU
$ fs where /afs/e.kth.se
File /afs/e.kth.se is on hosts elektrien.e.kth.se basalt.e.kth.se pyrit.e.kth.se
$ fs where /afs/athena.mit.edu
File /afs/athena.mit.edu is on hosts HYDRA.MIT.EDU SCYLLA.MIT.EDU CHARYBDIS.MIT.EDU AJAX.MIT.EDU

A good starting point is http://www.openafs.org/. In the left lower
corner you will find the AFSLore Wiki which is part of the effors
to document things better than that they are now.

Harald.
Derrick J Brashear
2002-02-27 20:12:30 UTC
Permalink
Post by Frank Batschulat (Frank Batschulat)
Hi All,
I often get the problem to find out AFS managed
UFS filesystems, there is no info about the filesystems
AFS sits on top of in neither the crash dumps itself,
nor the /etc/mnttab or /etc/vfstab.
AFS /afs afs dev=100000 1011729826
/afs (AFS ):18000000 blocks 9000000 files
I'd really appreciate pointers to look at to
find out a AFS configuration in terms of
which AFS mountpoint/filesystem has which
underlying real FS mountpoint/filesystem.
Do you mean on what filesystem the disk cache lives, or something else?

AFS is a network filesystem, generally, so just like NFS mounted
filesystems, the actual data lives elsewhere; Unless you mean "where is
the disk cache stored" I don't think this question makes sense. If you
mean that, then I have no real suggestions.

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