I have Plan9 on primary IDE, and I mount dos partition from the secondary
IDE disk using a variation of /bin/c:

% cat /bin/d:
#!/bin/rc
dosmnt 2 /n/d:

I have the c: command in termrc commented out. I used a: and unmount /n/a:
earlier in the session.

When I try to access the directory 'd:\Plan9\Download' using 'ls
/n/d:/Plan9/Download' I get an error message:

dev 3 sector 4251141, read: 0, should be 4608

An 'ls /n/d:/Plan9' is successful.

I have attached a PowerQuest PartitionInfo report. I have swapped my primary
(which contains Plan9 and Linux) for my Windows 98SE disk.

The secondary disk is unchanged from my Plan 9 configuration. The second
disk is the one which contains D: (labeled ZETA21) in an extended dos
partition, plus BeOS, Linux Swap, and Linux partitions.

I am not sure how to get the same info out of Plan 9. What can I do to
capture more info to help diagnose this problem?

I ran a scandisk which detected no errors in D:.