Disk errors when copying

[Richard Tobin]

> > >> ad10: WARNING - READ_DMA48 UDMA ICRC error (retrying request)
> > >> LBA=435128800
> > >> ad10: FAILURE - READ_DMA48 status=51<READY,DSC,ERROR>
> > >> error=10<NID_NOT_FOUND> LBA=435128800
> > >> g_vfs_done():ad10s2g[READ(offset=175562145792, length=131072)]error = 5

> One of the rules of thumb when you have hardware problems with a new
> system (I'm assuming of course that these UDMA errors have been
> happening since the system was built)

In my case it happened once and did not recur.  But looking at the SMART
log on the disk it appears that it might have happened before without
my noticing.  I was copying the disk before moving it to a different
machine, so I probably won't be able to test it further.

I'm sending a PR.

-- Richard