Francisco Reyes wrote:
On Thu, 22 Sep 2005, Eric Anderson wrote:
Also, if it is an NFS server, one should check the cpu times on the
nfsd processes. I've found that many times there aren't enough nfsd
processes to take the load from many clients. Increasing the number
(double it) often helps this. The max in 5.3 is 20, but you can
easily change it and get around it.
What is the parameter to change the number of nfsd processes?
Use the -n flag to nfsd, so in /etc/rc.conf:
nfs_server_flags="-u -t -n 1024"
Yep, that's right, I have mine set to 1024. How I got to that number
is simply by watching the cpu time on my nfsd processes. I do this:
ps -auxw | grep nfsd | head -n 20
Which would reveal something like:
root 410 4.2 0.0 1236 732 ?? S 13Sep05 1400:55.70 nfsd:
server (nfsd)
root 411 0.0 0.0 1236 732 ?? S 13Sep05 320:48.27 nfsd:
server (nfsd)
root 409 0.0 0.0 1352 924 ?? Is 13Sep05 0:00.47 nfsd:
master (nfsd)
root 412 0.0 0.0 1236 732 ?? S 13Sep05 83:29.31 nfsd:
server (nfsd)
root 413 0.0 0.0 1236 732 ?? S 13Sep05 39:18.94 nfsd:
server (nfsd)
root 414 0.0 0.0 1236 732 ?? S 13Sep05 25:16.79 nfsd:
server (nfsd)
root 416 0.0 0.0 1236 732 ?? S 13Sep05 19:39.53 nfsd:
server (nfsd)
root 417 0.0 0.0 1236 732 ?? S 13Sep05 15:23.14 nfsd:
server (nfsd)
root 418 0.0 0.0 1236 732 ?? S 13Sep05 13:05.99 nfsd:
server (nfsd)
root 419 0.0 0.0 1236 732 ?? S 13Sep05 11:05.15 nfsd:
server (nfsd)
root 420 0.0 0.0 1236 732 ?? S 13Sep05 9:59.39 nfsd:
server (nfsd)
root 421 0.0 0.0 1236 732 ?? S 13Sep05 8:39.97 nfsd:
server (nfsd)
root 422 0.0 0.0 1236 732 ?? S 13Sep05 7:34.38 nfsd:
server (nfsd)
root 423 0.0 0.0 1236 732 ?? S 13Sep05 6:56.37 nfsd:
server (nfsd)
root 424 0.0 0.0 1236 732 ?? S 13Sep05 6:40.99 nfsd:
server (nfsd)
root 425 0.0 0.0 1236 732 ?? S 13Sep05 6:08.44 nfsd:
server (nfsd)
root 426 0.0 0.0 1236 732 ?? S 13Sep05 5:40.81 nfsd:
server (nfsd)
root 427 0.0 0.0 1236 732 ?? S 13Sep05 6:34.98 nfsd:
server (nfsd)
root 428 0.0 0.0 1236 732 ?? S 13Sep05 4:34.36 nfsd:
server (nfsd)
root 429 0.0 0.0 1236 732 ?? S 13Sep05 3:17.89 nfsd:
server (nfsd)
That's on a very fast box, with a fiber channel connected 16 disk
RAID0+1, with the fastest disks I can buy. Now, with slower disk back
end, you'll probably see something more like this:
root 438 0.0 0.1 1372 964 ?? Is 17Jun05 0:03.14 nfsd:
master (nfsd)
root 439 0.0 0.1 1224 744 ?? S 17Jun05 1010:27.86 nfsd:
server (nfsd)
root 440 0.0 0.1 1224 744 ?? I 17Jun05 231:17.30 nfsd:
server (nfsd)
root 441 0.0 0.1 1224 744 ?? I 17Jun05 125:17.14 nfsd:
server (nfsd)
root 442 0.0 0.1 1224 744 ?? I 17Jun05 76:30.62 nfsd:
server (nfsd)
root 444 0.0 0.1 1224 744 ?? I 17Jun05 94:18.99 nfsd:
server (nfsd)
root 445 0.0 0.1 1224 744 ?? I 17Jun05 54:48.31 nfsd:
server (nfsd)
root 446 0.0 0.1 1224 744 ?? I 17Jun05 63:40.74 nfsd:
server (nfsd)
root 447 0.0 0.1 1224 744 ?? I 17Jun05 38:29.15 nfsd:
server (nfsd)
root 448 0.0 0.1 1224 744 ?? I 17Jun05 46:12.29 nfsd:
server (nfsd)
root 449 0.0 0.1 1224 744 ?? I 17Jun05 15:24.99 nfsd:
server (nfsd)
root 450 0.0 0.1 1224 744 ?? I 17Jun05 13:20.40 nfsd:
server (nfsd)
root 451 0.0 0.1 1224 744 ?? I 17Jun05 28:09.07 nfsd:
server (nfsd)
root 452 0.0 0.1 1224 744 ?? I 17Jun05 11:19.46 nfsd:
server (nfsd)
root 453 0.0 0.1 1224 744 ?? I 17Jun05 19:34.98 nfsd:
server (nfsd)
root 454 0.0 0.1 1224 744 ?? I 17Jun05 9:59.46 nfsd:
server (nfsd)
root 455 0.0 0.1 1224 744 ?? I 17Jun05 8:36.71 nfsd:
server (nfsd)
root 456 0.0 0.1 1224 744 ?? I 17Jun05 7:28.79 nfsd:
server (nfsd)
root 457 0.0 0.1 1224 744 ?? I 17Jun05 6:18.29 nfsd:
server (nfsd)
root 458 0.0 0.1 1224 744 ?? I 17Jun05 5:43.77 nfsd:
server (nfsd)
See how much run time that 20th process has? I like to always have a
couple with zero run time. So I double the number until I get there,
then tune back a little. I've found that a very rough rule of thumb is:
number of nfs clients * 1.8 = nfsd processes
as long as you have the memory for it. You should consider about:
nfsd processes * 2.5MB = memory desired for all the nfsd's
Eric
--
------------------------------------------------------------------------
Eric Anderson Sr. Systems Administrator Centaur Technology
Anything that works is better than anything that doesn't.
------------------------------------------------------------------------
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