[OpenAFS] Catastrophic r/w performances on Linux OpenAFS client
Michael Loftis
mloftis@wgops.com
Fri, 02 Jan 2004 11:04:05 -0700
No firewalls, traffic shapers, running on either machine, at all? Also you
didn't mention system hardware specs either...
--On Friday, January 02, 2004 12:46 +0100 lstep@adequat.net wrote:
> Hello,
>
> I've installed a test OpenAFS server (debian packages, v1.2.10, dbserver
> and fileserver on a same machine) and a client on another machine
> (debian package, v1.2.10). I made a volume for one of my user (the only
> one :-) and I'm trying to make it have some decent performance.
>
> Everything works fine except it's exceptionnaly slow. The client local
> cache seems to be correctly configured:
>
> bash-2.05b$ fs getcacheparms
> AFS using 13 of the cache's available 100000 1K byte blocks.
>
> But when I try to create a file, I see a bottleneck where it never goes
> above 5KB/s! In fact, it seems locked to 5KB/s
> When trying to create a simple file of 1Mo:
>
> bash-2.05b$ dd if=/dev/zero of=fichier.raw bs=1024k count=1
> 1+0 records in
> 1+0 records out
> 1048576 bytes transferred in 190.847965 seconds (5494 bytes/sec)
>
> Or even a file of 256k:
>
> bash-2.05b$ dd if=/dev/zero of=fichier.raw bs=256k count=1
> 1+0 records in
> 1+0 records out
> 262144 bytes transferred in 46.871588 seconds (5593 bytes/sec)
>
> I tried to create a file up to 2777 bytes, where it still makes 5KB/s.
> Below, it creates the file at 653Ko/s, but I guess it's not really
> representative, as the filesize is so small.
> But, for any size, it *always* transfer the data exactly at 5KB/s.
>
> I even activated the storebehind option, but it didn't change anything:
>
> bash-2.05b$ fs storebehind -allfiles 2048 -verbose
> Default store asynchrony is 2048 kbytes.
>
> Making a tcpdump on the client machine, I noticed a lot of traffic, the
> packet sizes set to the maximum (I think):
>
> 10:03:59.451896 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:03:59.452007 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.453560 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:03:59.453730 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.453777 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.960355 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.961905 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:03:59.962009 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.963557 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:03:59.963736 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:03:59.963784 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.470368 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.471921 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:04:00.472072 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.473632 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:04:00.473760 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.473806 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.980346 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.981915 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:04:00.982026 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.983590 192.168.0.7.7000 > 192.168.0.36.7001: rx ack (65) (DF)
> 10:04:00.983681 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
> 10:04:00.983711 192.168.0.36.7001 > 192.168.0.7.7000: rx data (516) (DF)
> 10:04:01.490370 192.168.0.36.7001 > 192.168.0.7.7000: rx data (1440) (DF)
>
> (192.168.0.36 being the client machine, and 192.168.0.7 being the OpenAFS
> server).
>
> The options I set where the one set by default on the afs.conf file
> created by the debian package script (I added the chunksize, without any
> change):
>
> /usr/sbin/afsd -stat 2800 -dcache 2400 -daemons 5 -volumes 128 -chunksize
> 20 -dynroot -fakestat -afsdb -nosettime
>
> I'd like to know if there is some parameter that I might have
> forgotten/not set that locks the bandwidth to 5KB/s, or how can I debug
> that problem, I don't know of any way/tools to see what's wrong.
>
> Thanks for your help,
> Luc
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--
Undocumented Features quote of the moment...
"It's not the one bullet with your name on it that you
have to worry about; it's the twenty thousand-odd rounds
labeled `occupant.'"
--Murphy's Laws of Combat