Subject: Re: FTP throughput problems
From: Jon L. Gardner (jon@food.tamu.edu)
Date: Fri Dec 17 1999 - 21:49:19 MST
on 12/16/1999 10:26 PM, Jon L. Gardner at jon@food.tamu.edu wrote:
>> I'm running YD on a StarMax 5000/275 with 128Mb RAM, and I'm getting
>> extremely poor throughput with the proftpd daemon. A client on the local
>> switched Fast Ethernet can only push about 500K per minute to the YD server.
>> I've updated proftpd to the latest version to see if that would help, but it
>> doesn't. Any ideas?
>
> Well, the plot thickens. The drive to which I'm transferring data is a 50Gb
> LVD U2W on an Adaptec card, and I hadn't restarted the box since formatting
> & mounting the filesystem on that drive. After a restart, ftp clients were
> able to transfer at appropriate speeds; however, now that it's been running
> for several hours, the throughput speed is dropping off again. It's doing
> about 6Mb/min at present, and it started out doing better than 90Mb/min.
>
> Is there something in the kernel, or maybe in the driver for the Adaptec U2W
> card, that would cause this sort of gradual degradation in I/O performance?
OK, it's not the drive, and it's not the SCSI card, because I've checked the
throughput to both the U2W and the "stock" IDE drive. It's also not the ftp
daemon; I've tried the latest versions of both proftpd and wu-ftpd, with no
noticeable difference in performance.
Right after a restart, I get great throughput, but as time goes on it starts
losing ground. I restarted the box this morning, and was getting
70-90Mb/min. throughput. Now, 12 hours later, I'm getting about 7Mb/min.
throughput from the same client with the same files.
Something's going on in the OS that's causing this huge performance hit to
develop over time. Can one of you YellowDog types please give me some
feedback?
<><
Jon L. Gardner, Computer Systems Manager <mailto:jon@food.tamu.edu>
Texas A&M University Dept. of Food Services <http://food.tamu.edu/>
Tel 409.458.1839 Fax 409.845.2157 ICQ 34792860
PGP public key available at <http://food.tamu.edu/pgp/jon.html>
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