On Mon, 6 Dec 1999, leo swl wrote:
> I believe there are a lot of experienced AFS
> administrators on this list, and hope to get
> answers/advice to some of the following questions.
>
> (1) How big can an AFS cell be realistically set up,
> in terms of number of AFS accounts, disk capacity
> available and used?
>
A fair number. Our cell (psu.edu) has just over 260,000 principals right
now. It's running on an older IBM RS/6000 model 370, so it doesn't need
alot of horse power or RAM (128MB). We had to upgrade from a Sun Sparc 1+
with 64MB RAM about two years ago as that started having paging problems.
The db files on the DB server are about 50MB each now (kaserver, prdb). We
don't have alot of disk space. We have about 35,000 volumes using 150GB on
two fileservers. I've heard of other places having 10s of fileservers and
over a terabyte of disk space. We're moving this cell from AFS to DCE/DFS
and our servers need at least 768MB of RAM now and this is for only about
110,000 principals.
> (2) How big are the bigger AFS cells today?
>
It's my understanding that ours is one of the largest in terms of number of
principals.
> (2) What are the hard limits?
>
Maybe someone from Transarc can answer this.
> (3) What are the potential pitfalls in setting up a
> big AFS cell? Does the AFS backup database
> performance scale with a large number of AFS volumes?
>
About four years ago when I first started managing this AFS cell we tried
using three database servers, but to send a new copy of the databases from
the master to the slaves took 40 minutes or so. FTP was faster than
whatever mechanism AFS was using to do the updates. We decided we were
better off with one server and a ready to go drive. We could swap a drive
and restore the database files from ADSM faster than AFS could update the
slaves in a 'disaster'. Network hiccups also caused the database servers to
get out of sync and this occurred too many times. Yes, we could loose up to
a days worth of updates, but it was decided this was OK. Now we use
mirrored drives on the DB server.
> (4) What kind of ratio do you have on users/server?
>
> (5) Does anyone have an experience using NetApp filers
> for a large user population (>30K users or even >100K
> users, for example)? How would managing a large
> number of NetApp filers compare with managing a large
> number of AFS servers? How many users does NetApp
> support per filer in reality?
>
> Thanks in advance for your response to any of the
> above questions.
>
> Leo
>
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- Mike
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Mike Burns UNIX Systems Group
[EMAIL PROTECTED] Center for Academic Computing
+1 814 863 5606 The Pennsylvania State University
