Hi,
we have a Dell 2950 with SAS RAID disks and RHEL. On this we run VM's with VMWare. Frequently I lose pings to the VM's but not to the host machine.
System Log entries in RHEL with same time stamps as dropped pings are:
srv01 kernel: hda: irq timeout: status=0x0d (Busy)
srv01 kernel: hda: failed opcode was: unknown
srv01 kernel: hda: ATAPI reset complete.

I'm new to Linux, and would appreciate suggestions on what the problem/solution might be.

Thanks, Colm.

A lot of the time you'll get errors like this on optical media drives when the media that has been inserted is damaged. If you try another disc that doesn't have any scratches or scuffs on it you probably will see the number of occurrences go down significantly. An alternative would to be to make images of the optical discs you wish to use and store them on the hard drive. You can easily make a copy of a CD or non copy protected DVD by using the 'dd' command.

For example to make a copy of the disc in /dev/hda into the file disc.iso you'll do this:
dd if=/dev/hda of=disc.iso

This file that is created will be mountable with vmware directly or you can use linux to mount it like this:
sudo mount -o loop disc.iso /mnt/disc

Which will mount that disc image at /mnt/disc

Hope this helps!

But there is no disk in the cd drive.
Any other possibility?

Did you ever figure this out? I'm seeing the same thing on another system