Re: P200 + 128M + 1.1.15 + Network Appliance = SLOOOOOOOOOOWWWWWWWW

On Mon, 25 Aug 1997, Kyle R VanderBeek wrote:
>The only thing I'd be concerned about in this capacity is that, last I
>checked, Linux's NFS implementation runs in user space and is consequently
>slower than many others. I'd be willing to bet that this is why your dual
>PPro system is running so much better than your single Pentium systems.
>Check load averages/top and see just who is sucking the most power: is it
>squid or nfsd?

The NFS server (the daemon, rpc.nfsd) runs in userland. The NFS
filesystem (ie, client) is mostly in kernelspace.

NFS server:
root 4 0.0 0.0 0 0 ? SW Aug 12 0:00 nfsiod
root 5 0.0 0.0 0 0 ? SW Aug 12 0:00 nfsiod
root 6 0.0 0.0 0 0 ? SW Aug 12 0:00 nfsiod
root 7 0.0 0.0 0 0 ? SW Aug 12 0:00 nfsiod
root 379 0.3 0.1 1192 784 ? S Aug 12 74:30 /usr/sbin/rpc.nfsd

NFS client:
root 4 0.0 0.0 0 0 ? SW Jul 30 0:16 nfsiod
root 5 0.0 0.0 0 0 ? SW Jul 30 0:17 nfsiod
root 6 0.0 0.0 0 0 ? SW Jul 30 0:17 nfsiod
root 7 0.0 0.0 0 0 ? SW Jul 30 1:28 nfsiod

nfsiod's are kernel threads in userspace just how most unicies implement
the NFS client side (actually, Digital Unix has a single userland process
which multithreads appropriately; SunOS has a serious of userland
processes IIRC... but the effect, scheduling, performance, etc is all
similar). Only Linux doesn't support the lockd system, so it doesn't need
client side daemons for that. IIRC, the nfsiod's are kernel threads so
that they don't have to copy from and to kernel memory space, a saving
over fully userland nfsiod systems.

David.
Received on Mon Aug 25 1997 - 19:15:24 MDT