Coda File System

Re: speculative questions

From: Phil Nelson <phil_at_cs.wwu.edu>
Date: Sun, 31 Mar 2002 16:19:10 -0800 (PST)
>    Question:  Can I replicate the N volumes across both
>    disk A and B so that if a disk goes down I'm still OK?
>    What if I use two server processes?

Yes, you could use two server processes and replicate them
across both disks.  The two server processes need different
IPs and would look like different servers.   I would think
that using two machines would be better.  You get protection
not only from disk crash, but from other things like OS crash.
One machine down wouldn't make the replicas inaccessable.


>    Assume three servers A, B, C and three volumes X,Y,Z.
>    Is a topolgy like the following allowed: 
>       A holds X, Y
>       B holds Y
>       C holds Z, X

Yes, it is.

>  - Does coda allow for SSL tunneling between the clients and
>    the servers (and between the servers)?  Does this have to
>    be external to Coda or is/can it be incorporated easily?

To my knowledge, this not available yet.  I believe it could be
added to the rpc2 package.

>  - How is performance?  Would a ton of little files or a few
>    big files really slow things down?  Can Coda support 
>    tens-of-thousands of volumes, each about 10M-50M?

Large installations like this still have some problems.   There
were just some reports of writing lots of files to a server. Also,
a problem with big files is that they need to be smaller than the 
client cache to be fetched from the server.  Coda does whole file
caching.

>  - Can volumes be dynamically resized and given size restrictions?
>    Can volumes be added/deleted/moved between servers easily?

I understand there are quotas on volumes, but I haven't used them.
The volumes are not created with a "size" attached.

As for added and deleted, that is easy.  Currently, I haven't heard
that one can move volumes around between volume storage groups.  

I hope this answers many of your questions.

--Phil

-- 
Phil Nelson                       NetBSD: http://www.netbsd.org
e-mail: phil@cs.wwu.edu           Coda: http://www.coda.cs.cmu.edu
http://cs.wwu.edu/faculty/nelson 
Received on 2002-03-31 19:20:28