Hi,
Reading though the mailing list, it became obvious that many are
concerned about the venus cache size. There seemed to be unanimity
about the fact that one needed a larger venus cache than the file
being manipulated under /coda.
My previous mail on the subject claimed that one could open a 20MB
file with a 10MB cache.
Here is a description of the corroborating experiment:
- A single client running Linux RH 5.2,
- Two Servers RH 6.0,
- One of the servers, called gilgamesh, is old (486 66Mhz, 16MB, 700MB)
- The other server, called torino, is much faster (AMD K6, 128MB, 13GB)
- Client configured with 10MB of venus cache, two servers.
- Client *does not* do hoarding.
I issued the command,
> dd if=/dev/zero of=/coda/zero bs=1024 count=20000
while both servers were up. I observed that the client would contact
both servers. Many packets were exchanged, presumably 20MB of
zeroes. However, I cannot really tell if the servers were contacted in
turn or in parallel.
I issued the command,
> filcon parition -s torino -c napoli
where torino is the faster server, and napoli is the client. This
disconnects torino and napoli. Other connections are not
affected. BTW, isn't filcon an open invitation for denial-of-service
attack?
Then, I issued the "dd" command exactly as previously.
I observed that the client talks to "gilgamesh", the older
server. Interestingly enough, the two servers did not seem to talk to
each other. However, when I did a "ls -la /coda" on the client, there
was intense activity between the two servers, presumably synchronizing.
In both cases, the file /coda/zero was there. The client did not crash
and /coda remained accessible. There were no apparent error
conditions either.
AFAICT, strongly connected clients (and no hoarding) can manipulate
files of any size independently of cache size. Ceki
