[OpenAFS] Re: Client using static-sized kernel datastructures?

[James L Robinson]

Derek Atkins writes:

>Eh?  It's not static -- it's set at runtime.  It's just not
>_ADJUSTABLE_ without stopping and restarting the client.

Of course, that's what I meant. I used 'allocated statically'
to mean 'just once', as opposed to dynamically resized
upon demand needs. The MAXUSERS comment was
misleading.

>This is what we inherited from Transarc.  Why don't you send us
>patches that are up to snuff that work on all supported platforms?

Gotcha!


>In all seriousness, this is actually on the list of "things to do" for
>Linux -- make AFS use the Linux inode table instead of AFS maintaining
>its own in-kernel array.  So, I'm not even convinced it needs to be a
>portable solution to be accepted.  It does, however, need to be "up to
>snuff". ;)

That's cool for me, running Linux clients. I'd hate to see it
not followed through to find the equivalent mechanisms under
the other platforms -- I believe that we had some multiuser
Sun boxes go down in a panic on campus via a similar
issue. When the user brought down the first shared
X-server box, looks like they just logged into one
of the other available ones and did the exact same
thing :-( .

As a related aside, and forgive me if I've overlooked
an obvious answer, but is there any way for userland
to examine the usage stats of these onetime-allocated
datastructures? I see "fs getcacheparms" can give
a heads-up on disk / memory cache usage, but
how's an admin to know when we're, say, with 10%
of the AFS inode cache size, so you might want to start
lookin' for procs to kill before you wake up and smell
the panic?

Nathan Neulinger writes:
>Some of them have to do with how the data is structured. For example,
>changing the cache size - when done initially, it impacts the number of
>cache files created on disk, but when you change live, it just changes
>the size limit, but does not alter number of cache files.

I guess the userspace tool for this is "fs setcachesize" ? This
then makes the size per cache file bigger, if I get your drift?

--=20
James Robinson                          Phone: (704) 687-4876
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