When ever I plug in my thumb drive, use my USB floppy, use my optical drives, and/or turn on my external usb hard drive
I get an odd syslog message repeated several times for each drive
sd 0:0:0:0: [sdf] No Caching mode page present
sd 0:0:0:0: [sdf] Assuming drive cache: write through
This either happens early in the boot process before the system writes out the init version and it is populating /dev OR it happens as i attach a drive to an active running machine.
Also on a side note i noticed this initially because of a stopgap fix for a minor nuance with my USB floppy drive which was constantly moving its drive heads back and forth. Since i could not figure a way to fix that problem directly i just stuck a blank floppy in and that is when i noticed this issue if it is one.