Re: scsipi: physio split the request

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

On Thu, Dec 27, 2018 at 10:44:46AM +0100, Manuel Bouyer wrote:
> tape block size are usually larger than 512 (I use 64k here).

I patched ltfs so that all the max sizes (256kB and 512kB for Linux)
are set to 64kB for NetBSD. I can now format and mount the LTFS filesystem,
but I need to limit the block size to under 64kB.

This will work:
dump -0f - / | dd obs=63k of=/ltfs/dump20181227 

This hangs the filesystem:
dump -0f - / | dd obs=64k of=/ltfs/dump20181227 

I tested on glusterfs that our FUSE implementation does not limit writes
to 64k chunks, hence I assume I introduced a bug in ltfs with the 64kB 
limit everywhere.

Is there a reason other than historical for NetBSD 64kB limit?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost