[DM-MUG] Q ref MacBook Air and terminal message on screen

[Victoria L. Herring]

trying to boot off DiskWarrior [pre SL] before installing SL.  using 
the external usb drive.  All seems fine but came back to check it and 
message on screen says
SAM Multimedia:  Read or Write Failed, : ASC 0x11, ASCQ 0x00

this goes down 5 times then there is

disk1s1s2:  I/0 Error

1.  what do I do to get out of this and reboot back from the Air 
startup drive [I had attempted to book off the disk in the external 
drive using 'C'
2.  what does it mean

I guess I'll install DW onto the SuperDuper backup and then run it 
but for now these Q
-- 
Victoria L. Herring, Des Moines, Iowa. Blogs: 
http://blog.JourneyZing.com  [photography]; 
http://www.herringlaw.com  [civilrights/discrimination]; 
http://victorialherring.typepad.com/serendipity/  [personal].