[OpenAFS] How does AFS deal with non-AFS files on its partitions?

DavÝ­ Geirsson davidgeirs@gmail.com
Tue, 20 Jun 2006 16:36:12 +0000

2006/6/20, Mathias Feiler <feiler@uni-hohenheim.de>:
> Hello ,
> If I undersand You the right way .... (long answer)
> On Fri, 9 Jun 2006, David Geirsson wrote:
> |Hi all,
> |
> |I'm preparing to set up OpenAFS for a small network (3-4 users, ~500GB
> |of data to store). The server machine has 4x320GB IDE disks in a RAID5
> |configuration. There is no backup equipment set up, as this is for a
> |personal network and we can't afford it.
> |
> |I've read in the AFS docs (which I admit I'm still reading, so this may
> |be covered better later) that AFS likes to have its own dedicated
> |partitions, and that this is "strongly recommended". I am wondering,
> |however, what would happen? Will OpenAFS trample all the files? Because
> |the easiest solution for me here would be to let OpenAFS use the data
> |partition for its own files,
> As long as You use the namei-interface (Linux) ther is a way to mount
> /vicep* even if it is not a separate partition. But for now dont ask me f=
> the -option .
> |and then move files from that partition to
> |the AFS mount.
> Nice idea but not the way AFS is designd.
> Imho. the problem steps in on at least two points:
> (1) -- Accessmethod to the volumes on a vice partition --
> If You are using the origin inode interface to access the /vicep* (as it =
> common for Solaris and such) You just cannot move data into the /vicep*
> since ther is nothing to move it in. The only thing you see are 76 Byte
> files calles Vnnnnnnn.vol (e.g. V1920534048.vol) which represent the
> volumeheader. All the other things are hidden in a strange way. Thus You
> need a special fsck for such partitions.
> If You use namei for the /vicep* there is a directory strukture but the
> names are totaly srewd . You wouldn't succseed if You just write in.
> (2) --- Access control ---
> AFS got acl and volumes. Both of them needs to be represented in the /vic=
> While You are thinking of moving files into a vice partition by  unix mv
> you probably did not considder volumes (rw,clone,ro,backup) and acl
> The proper way is, to have a afs client running on the old fileserver (as
> well as  on the AFS server for conveniences) and just copy your data into
> the AFS using the afs client.
> Example:
>         # Create a volume
>          vos create afsserver vicepa prj.dump
>         # Mout the volume into the AFS-file tree
>          fs mkm /afs/.mySite/projects/dump prj.dump
>         # set the (initial) acl
>          fs sa /afs/.mySite/projects/dump dummy write
>         # Copy the data into the volume
>          cp -R /oldDump/* /afs/.mySite/projects/dump
>         # Eventually define a clone and/or replicate site of the volume
>          vos addsi afsserver vicepa prj.dump
>          vos addsi afsserver2 a     prj.dump
>         # Eventually do the replication of the volume
>          vos rel  prj.dump
> |
> |Anyway, help would be much appreciated.
> |
> Well it could be of advantage to join a AFS workshop :
> USA / english     :  http://www.central.org/workshop/index.html
> Germany / deutsch :  http://www.rz.uni-hohenheim.de/afsws06
> This might help to keep You from a few other newcomer-uups as well.
> Sincerely , Mathias
[snip sigs]

Hi Mathias, thanks for your reply.

I think you misunderstand my problem (I probably wasn't very clear in
my original mail)

The problem is that I need to get the files onto the AFS mount once
I've created it. At the moment they are on a single linux ext3

/dev/md0              881G  532G  349G  61% /data

/dev/md0 being the RAID5 array.

I want to set this array up as an AFS partition at /vicepa, but I have
nowhere to store the data while I set up AFS. I want to merge this
data into the AFS tree once it is operational. I was wondering what
would happen if I simply mounted the current filesystem, with the
files and directories currently on there. I realise that AFS wouldn't
recognise the files, and I couldn't use them on the AFS, but if they
are left alone, I can then move those files from /vicepa to the /afs
mount one file tree at a time, making them part of the AFS tree, all
the while without disturbing the filesystem already there.

I hope this made more sense than my previous post. Thanks for the
pointer to the workshops, I'd love to go. I doubt my finances will
allow me to attend this year unfortunately, but you never know.

With kind regards,
DavÝ­ Steinn Geirsson
Reykjavik, Iceland
+354 8696608