Possible IDE corruption bug?

[John Goerzen <jgoerzen%complete.org@localhost>]

Hi folks,

I have an AlphaPC 164LX (600MHz 21164a, 256MB RAM).

This machine ran Linux many years ago, and I'm now repurposing it for
NetBSD.

I downloaded the NetBSD 11.0 alpha ISO.  I successfully booted from it
(boot dqb0 at SRM).  I partitioned the drive, selected "Full
installation without X11", but I got the attached screen.

I went through, and HTTP installation from cdn.netbsd.org (via my Tulip
NIC) was fine.  However, I didn't trust an un-authenticated download, so
I tried it again.

Same thing.

This time, I opened a shell in the installer environment.  There were no
I/O errors in dmesg.  I could mount the CD fine (I made a directory at
/mnt3) and tried pointing the installer at that.  Same thing again!

I mounted the ISO on my file server and started a HTTP server over it,
and pointed the installer at that.  It worked fine.

I verified the SHA512SUM of the downloaded ISO.  It matches.

So on my installed system, I again mounted the CD and sent into
/cdrom/alpha/binary/sets and ran sha512 -c SHA512.

Now -- almost all of them are failing!

I tried copying xetc.tgz to my home directory.  I can scp the same file
from another box into there from another box.  The scp'd file is fine,
the copied one retains the bad hash from the CD.

I can compare them thusly:

alpha$ cmp -l xetc-real.tgz xetc.tgz
  7953   0  10
 10209 102 112
 18607 100 101
 25689 302 312
 34102  33  37

In case there was a problem with the burn, I mounted the same CD on a
Linux system and ran sha512sum -c SHA512.  All verify properly.  So it's
not a bad burn.

Both the CD drive and the HDD are IDE devices, connected to the
motherboard IDE.  I see this at boot:

[     4.110851] wd0 at atabus0 drive 0
[     4.111829] wd0: <IBM-DTLA-305040>
[     4.111829] wd0: drive supports 16-sector PIO transfers, LBA addressing
[     4.112805] wd0: 39266 MB, 79780 cyl, 16 head, 63 sec, 512 bytes/sect x 80418240 sectors
[     4.114757] wd0: 32-bit data port
[     4.114757] wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
[     4.115733] wd0(cmdide0:0:0): using PIO mode 4, DMA mode 2 (using DMA)
[     4.115733] atapibus0 at atabus1: 2 targets
[     4.122570] cd0 at atapibus0 drive 0: <TOSHIBA CD-ROM XM-6302B, , 1012> cdrom removable
[     4.124524] cd0: 32-bit data port
[     4.124524] cd0: drive supports PIO mode 4, DMA mode 2
[     4.125499] cd0(cmdide0:1:0): using PIO mode 4, DMA mode 2 (using DMA)

This has the smell to me of a kernel bug. 

I don't really care about the CD now that it's installed, but I'm
concerned about the implications.

Ideas?

Thanks,

John