terrible HD I/O speed on laptops where hdb is the CD (inspiron 8200)

[Peter Teuben]

This is a very old topic about which I've reported before and has
some old entries in redhat/fedora's bugzilla. But the basic problem is
that in order for desktops to "automatically" detect that a CD has
been added/removed, it has to poll /dev/hdb, but poor little /dev/hda
is then interrupted, at least on a Dell 8200 this causes the HD
performance to go down by about a factor 2-4.

hdparm then reports erratic I/O (5-10 MB/s, where the drive will do a
consistent 38 MB/sec in my case in single user mode).

In fedora5 and 6 this is now done by hald-addon-storage, which appears
in the process table as polling hdb.   I suspect it's a Dell 8200 problem
(hardware related), though i have an 8600 to play with, and a thinkpad T40
i can try as well.    It might also be the settings of the HD, i tried
playing with the hdparm options, but nothing will bring it back to a
consistent level, other than killing the polling task.   As said,this is
a very old topic.

I'd love to hear any other/more reports on this issue.  Eventually i'll 
file a bugzilla on this of course.

- peter