[rescue] tape drive with no SCSI

[Joshua D Boyd]

On Wed, Nov 07, 2001 at 07:19:08PM -0500, Patrick Giagnocavo wrote:
> >   Yes, it's a little scary, but...check this out.  The Netra X1 is a
> > 400MHz UltraSPARC-IIe in a 1U rackmount chassis with two 10/100
> > reefernet interfaces, and it ships with 128MB of RAM and a 20GB
> > [crappy IDE] disk...for $1000.00.  My application is almost entirely
> > memory-based so the IDE doesn't bother me all that much, aside from
> > the purism issue.
> 
> The real problem with IDE is that the drivers need to be properly
> written - sounds like (according to what I pick up on the web) that
> hasn't happened for Solaris.
> 
> You can get equivalent performance and equivalent CPU usage out of IDE
> as long as you are in UDMA-2 mode or higher.  See if you can find out
> what PIO or UDMA mode the Netra is running at.  If you can change it,
> you might get both a performance boost and a decrease in CPU usage when
> banging the disk heavily.

My drives and controller on my lintel station are UDMA.  All reasonably 
new stuff, no fancy hardware, default BIOS settings (except to make it 
boot CDROM then floppy, then HD, instead of the opposite order).  Stock 
debian installation.  

Now, recently I was running a memory based program, that logged its 
results to disk, about 50bytes, after 5 minutes of working or so.  I could 
watch the CPU meter for both CPUS, and the program would be maxing both of 
them until it went to write to disk.  Then CPU activity would drop nearly 
entirely for about 1.5 seconds (although the mouse and XFree seem 
responsive). Now, if you are wondering if I was doing something funky in 
the way I was writing to disk, I wrote the program to just cout the 
results, the redirected stdio to a file (ie, ./a.out > results).  

When I moved the results file to a network drive, the program stopped 
pausing on printing the results.  After that, I'm even less happy with IDE 
than I was, and I'm thinking of adding a SCSI drive just for the swap 
partition, and for scratch space.

-- 
Joshua D. Boyd