sa(4) driver changes available for test

[Kenneth D. Merry]

On Thu, Feb 26, 2015 at 10:57:50 +0100, Harald Schmalzbauer wrote:
>  Bez?glich Kenneth D. Merry's Nachricht vom 19.02.2015 01:13 (localtime):
> > I have updated the patches.
> >
> > I have removed the XPT_DEV_ADVINFO changes from the patches to head, since
> > I committed those separately.
> >
> > I have (hopefully) fixed the build for the stable/10 patches by MFCing
> > dependencies.  (One of them mav did for me, thanks!)
> >
> > Rough draft commit message:
> >
> > http://people.freebsd.org/~ken/sa_changes_commitmsg.20150218.1.txt
> >
> > The patches against FreeBSD/head as of SVN revision 278975:
> >
> > http://people.freebsd.org/~ken/sa_changes.20150218.1.txt
> >
> > And (untested) patches against FreeBSD stable/10 as of SVN revision 278974:
> >
> > http://people.freebsd.org/~ken/sa_changes.stable_10.20150218.1.txt
> 
> Ken,
> 
> thank you very much for your work!
> Last sa(4) overhaul (with 10.0 I guess) was a great success and I highly
> appreciate your work on tape support for FreeBSD!
> I compiled your 10-stable patchset for one machine with LTO2 and DDS5
> drives, but haven't done much testing since I'll replace the adaptec
> (39160) because it's maxio is limited to 64k (while 53c1020 has 128k).
> sa(4) seems to work just fine with both drives, mt(1) showing "Reported
> File/Record Number" :-) No EOM tests done so far?

I'm glad it is working well for you!  You can do larger I/O sizes with the
Adaptec by changing your MAXPHYS and DFLTPHYS values in your kernel config
file.  e.g.:

options         MAXPHYS=(1024*1024)
options         DFLTPHYS=(1024*1024)

If you set those values larger, you won't be able to do more than 132K with
the sym(4) driver on an x86 box.  (It limits the maximum I/O size to 33
segments * PAGE_SIZE.)

> I'll archive zfs streams, therefore I needed some kind of forward error
> correction. Probably people following this thread also have found to
> need this, therefore I'd like to point to the new port misc/vdmfec
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=197950
> Perhaps someone want's to take this bug report.

That looks cool. :)  I'm not a ports committer, but hopefully one of them
will pick it up.

Ken
-- 
Kenneth Merry
ken at FreeBSD.ORG