[comp.unix] RFS vs. NFS

ajr@hjuxa.UUCP (Karen Paszamant) (07/25/87)

I am looking for any articles comparing RFS on System V release
3 to 4.2 BSD's NFS. Is there anything out there that is published
or waiting to be? It doesn't have to be real general either.

Thanks
ajr

rup@keba.UUCP (07/27/87)

In article <1190@mcdchg.UUCP>:
>I am looking for any articles comparing RFS on System V release
>3 to 4.2 BSD's NFS. Is there anything out there that is published
>or waiting to be? It doesn't have to be real general either.
Refer to the EUUG Proceedings from the manchester-conference.
There's been a lot discussion about that stuff. 
You may reach EUUG by euug@inset.uucp.
--
Rup Grafendorfer
c/o KEBA, Gewerbehof C
A-4040 Linz,Austria,Europe
++43-732-230911-94
UUCP: mcvax!tuvie!keba!rup

zs01+@andrew.cmu.edu (Zalman Stern) (05/20/88)

> Bunch of stuff about how stateful filesystems crash and burn when a server
crash.

Here at CMU (the Andrew project) we use the Andrew Filesystem (AFS). (Known as
"VICE" to its friends.) This is a very stateful filesystem and provides very
good performance under high load conditions. (Most of our servers are have
about 100 active clients at a time.) This is of course due to local disk
caching. When a server goes down, you cannot access any files on that server.
You get a message on the console saying that server such and such is down, and
all file access to that server return ETIMEDOUT. When the server comes back up,
everything returns to normal. I hardly call this "messy."

>From what I understand about NFS, it becomes flakey under adverse network
conditions or high server load. For example, one benchmark we ran tried to put
20 clients on an NFS server. The benchmark would attempt to do a mkdir system
call (for a directory that did not exist) and get back an EEXIST error. What
happened was the server got the mkdir request packet and sent a response
indicating success. The response got dropped, so after a while the client
retried the initial request. This time, the mkdir request hit the server and
the directory had already been made by the first request. So the server sent
back an error return. I suppose this is a consequence of mkdir not being
idempotent. If this is a bug, fine. On the other hand, if it is a property of
stateless remote filesystems, they should be nuked til they glow.

Finally, a request for info. We are currently testing a new mechanism to handle
UID -> name mapping for separately administered shared filesystems. (That is,
users on machine A want to look at files on machine B but don't want to see B's
UIDs translated to A's names...) Someone mentioned that RFS gets this right. I
would appreciate it if someone could send me mail summarizing how this works in
RFS.

Sincerely,
Zalman Stern
Internet: zs01+@andrew.cmu.edu     Usenet: I'm soooo confused...
Information Technology Center, Carnegie Mellon, Pittsburgh, PA 15213-3890