5.1R - lock up on drive error

I came to work this AM to find my machine (P4 w/5.1Release) locked up
and it displayed multiple lines of the error message below, can anyone
shed a little light on the following error? Is this simply the sign of a
dying drive (which I don't believe is the case.. but you never know) or
is this a 5.x issue?

This drive is UFS2

ad1: hard error cmd=read fsbn -9598600583780852 of
-9598600583780852--9598600583780821 status=51 error=04

-E-

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