[OpenAFS] newbie questions

Papp Tamás tompos@martos.bme.hu
Tue, 11 Nov 2008 17:35:45 +0100

Lars Schimmer wrote:
>> - there is one partition, which is the root.cell and root.afs (do I say
>> well, are them same?)
> No, one is /afs and one is the "root" of your cell, in my case root.afs
> is /afs and root.cell is /afs/cgv.tugraz.at.
Well, good to know, of course it's logical way, if I think on it..

> Hi!
> If possible, try to disable the crypto option for the client.
> Without crypto I reach 30-50 MB/sec on gbit network (which is limited
> mostly by the client hardware).
Well it sounds good, but I don't find, how can I disable it?
> Each fileserver could host up to 256(?) partitions /vicep(a-zz).
> Just add a new partition /vicepb and add it to the filserver and restart
> OpenAFS fileserver.
... and how to add a new partition, exactly that's my question. I've 
tried it with vos create..., but I think I miss something.
I searched the whole internet, but no luck, everywhere is full with 'set 
up openafs', but not with adding a new fileserver:)

> The best solution to maintain load balancing and failure security is to
> add another fileserver (or even more), each with its own /vicepa.
Yes of course, this would be only a test system.

>> 3. What happens, if the somehow one of partitions disappears (eg. hdd
>> get wrong, like a node server),l what is the right protocoll in this
>> case, is there more possibilities? Did I miss something is the docs?
> If one partition went away, it is no more reachable. But if you setup
> another FS or another partitions (and created ReadOnly copies of your
> ReadWrtite volumes on that partitions) OpenAFS will use the still
> available RO copies on the remaining partitions.
I gues, it in the howto, how to do it.
Right now I'm interesting in if the clients will be locked up, or only 
they miss the files?
>> 4. Is there any piossbility to replicate meta data's (root.afs?), and
>> also is there any failover solution about it? I'm sorry, I'm working
>> only with Lustre, I know only its terminology.
> Replicate ONLY MetaData is not possible in usual OpenAFS (imho it is
> with the Object Storage system).
> The usual way in OpenAFS is to create volumes and mount the volumes into
> the AFS space (in my case e.g. volume "homes" is mounted on
> /afs/cgv.tugraz.at/home). The volume itself contains the data,
> directories and the quota and ACL information.
> The volume resist on one of the partitions your fileservers are providing.
> OpenAFS provides functions to replicate those volumes and copy the
> replicated volumes onto the same and/or other partitions.
> Which ends up in: you need to to some magic by yourself, but if done
> right, one fileserver can go down and users does not notice at all.
> And you can do load balancing fairly easy (even via worldwide slow lines).

Great. If I understand well, all server replicate contains its 'meta' 
data too.

Thank you,