Subject: Re: large disk preformance
To: Tyrel Beede <tb90@mail.csuchico.edu>
From: Brian Hechinger <wonko@entropy.tmok.com>
List: current-users
Date: 04/07/2001 17:06:30
Tyrel Beede drunkenly mumbled...
> I recently replaced my 4.5 GB UW SCSI @ 7200 rpm drive with an IDE 30 GB
> @ 5400 rpm.  The switch wasn't optional and I've come to notice that the
> new drive lags with interactive preformance every now and then.  For
> example I'll be running a vi session and things will just kinda bog
> down, it seems to occur at random points( some of the time just after a
> reboot and others after the machine has been up for a few days ).  The
> lag is kinda like working with a vi session over a slow telnet link.
> I'll type on the keyboard and a few seconds later the commands will show
> up.  I've got 96 megs of ram in the machine and I don't even have X
> installed so the machine isn't really being hit hard for memory.  This
> problem isn't really that big because the lag only happens every now and
> then... maybe once a day.  But it never happend on my SCSI drive running
> the same kernel.  Anybody have any tuning ideas?

well, first off:

UW SCSI @ 7200 rpm -vs- IDE @ 5400 rpm

you lose the greatness of SCSI and 1800 rpms so there is a big speed difference
here.  vi opens tmp files, so you are getting slowness when vi is accessing
those tmp files.

if you have the room for both drives, mount the IDE as /home and run the system
off the SCSI.  4.5GB is more than enough for a maxed out system and /home
doesn't need to be too fast, as long as you aren't expecting it to do much 
other than hold data that has no performance requirements.

also, does vi use /tmp or .

something to look into, force vi to use /tmp after you put the SCSI back in if 
it doesn't.

cheers,

-brian