Re: SCSI Tape corruption - update

[Lorenzo Marcantonio]

On Tue, 8 May 2001, Geert Uytterhoeven wrote:

> In the mean time I down/upgraded to 2.2.17 on my PPC box (CHRP LongTrail,
> Sym53c875, HP C5136A  DDS1) and I can confirm that the problem does not happen
> under 2.2.17 neither.
>
> My experiences:
>   - reading works fine, writing doesn't

Same here

>   - 2.2.x works fine, 2.4.x doesn't (at least since 2.4.0-test1-ac10)

SAME here

>   - hardware compression doesn't matter

SAME HERE

>   - I have a sym53c875, Lorenzo has an Adaptec, so most likely it's not a
>     SCSI hardware driver bug
>   - I have a PPC, Lorenzo doesn't, so it's not CPU-specific
>   - corruption is always a block of 32 bytes being replaced by 32 bytes from
>     the previous tape block (depending on block size!) (approx. 6 errors per
>     256 MB)

YESSS... EXACTLY 32 consecutive bytes are different. I'll bet we've got
the same problem

>   - How many successive bytes are corrupted?
>   - Where do the corrupted data come from?

Hmmmm.... I'll set up some sort of binary pattern match. This afternoon
I'll pinpoint the source of the rogue bytes...

				-- Lorenzo Marcantonio