Re: FTP throughput problems


Subject: Re: FTP throughput problems
From: Jon Gardner (jon@food.tamu.edu)
Date: Tue Dec 21 1999 - 08:37:36 MST


on 12/21/99 9:16 AM, Jon Gardner at jon@food.tamu.edu wrote:

>>> 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.
>>
>> Is it *only* IO performance that degrades over time? Have you checked to
>> make sure that some other process isn't sucking down system resources?
>> Perhaps something leaking memory until it starts pushing everything into
>> swap or something that starts up later and hammers the CPU?
>
> Nothing else looks amiss at all. I did a complete reinstall of YDL just to
> be sure, and monitored top while I was dumping about 20Gb of data to the
> system via ftp. The only two processes using any CPU to speak of were top
> and ftpd, and the memory was hanging stable at about 2Mb free actual, 2-4Mb
> swap used. I have noted that once the system slows down, all I/O seems to be
> affected...NFS, ftp to/from any drive, even copying data from one local
> drive to another.

An interesting tidbit...when copying an 800Mb file from the local LVD to the
local ATA, I only get about 2Mb/s throughput, even after a restart. Are
there any known problems with either Adaptec 2940U2W cards or the "stock"
IDE controller in StarMax boxes? I know the StarMax isn't officially
supported by YD, but according to LinuxPPC (of which YDL is a distribution)
it's supported hardware, as is the 2940...though I don't know about the U2W
part.

<><
Jon L. Gardner '89, 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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