A recent issue was discovered when assigning the media tray from one blade to another in an IBM BladeCenter. The problem was after you assigned the media tray to another Blade server, and ran cfgmgr to scan the bus, it wasn’t finding the USB CD-ROM. Trying to plug a USB Flash drive in and scanning the bus also resulted in the same effect. In the end, the issue was caused by the VIOS not “owning” the USB device adapter. It was a physical adapter that was assigned to one of the LPARs on the VIOS (on one of the blade servers). The fix was to bring down the LPAR, remove the USB adapter, assign it directly to the VIOS partition. The CD-ROM still couldn’t get discovered (by that blade or any other) until after the problematic system blade was rebooted.
Needless to say, it appears as though the VIOS server held a lock on the CDROM device which interfered with the ability to move the Media Tray assignment from one blade to another.
NOTE: It is way quicker to use the “remote drive” functionality instead of a USB Optical Device on the IBM Blade Chassis. Typical boot time for an AIX Media in the USB CDRW/DVD-RAM drive was about 30 minutes. Using remote drive took under 10 minutes.