Looking for PCI express SCSI diff card recommendations

[Kenneth D. Merry]

On Mon, Jan 14, 2019 at 09:49:09 -0500, Dan Langille wrote:
> > On Jan 14, 2019, at 9:10 AM, Ken Merry <ken at kdm.org> wrote:
> > 
> > So, if you???re interested in newer tape drives / libraries, the connection options are FC, SAS or (lately) RoCE.  The first two work fine, but I have yet to be able to test/qualify a RoCE drive with FreeBSD.  For FC, get a Qlogic board (up to 16Gb is supported now) or a 16Gb or newer Emulex board.  Both drivers support FC-Tape.  I have had much more experience with the Qlogic driver, but the Emulex driver does seem to work fine.  For SAS, get an LSI/Broadcom 12Gb or 6Gb board.  They support TLR, which is the SAS equivalent of FC-Tape.
> > 
> > The only current tape drive vendor is IBM, and you can get LTO (LTO-8 is the latest, 12TB/30TB per tape) or TS drives (TS1160 is the latest, 20TB/50TB) from them.  TS only makes sense for people with a big enterprise budget.
> 
> In my case, this is for home use, where I have no budget for tape libraries. The units I have are all production-cast-offs via kind donations.  Mind you, I did buy a Digital TL891 back in 2006 and it still works.  Photo of that beast here: https://www.freebsddiary.org/digital-tl891.php <https://www.freebsddiary.org/digital-tl891.php>  <--- that is the unit for which I wanted a new SCSI card, but now I think the easiest solution is to find another M/B (see below).
> 

Very understandable.  The last tape drive I actually bought myself was a
standalone DDS-4 drive.  Most of the rest of my personal tape hardware has
been donated, and is all pretty old at this stage.  (Which is useful for
tape driver compatibility testing, though.)

> > 
> > I believe HP stopped making their own tape drives at LTO-6.  Anything HP-branded that is LTO-7 or newer is going to be an IBM drive under the hood.
> > 
> > If you want a tape library, there are a number of options.  I know from copious experience (yes I work there) that Spectra Logic libraries work well with FreeBSD, and their support is good.  IBM should also work fine, and really, most libraries should work with FreeBSD without an issue.
> 
> I'm using a Dell TL4000 just now, connected via a SAS card (see below). The other two tape libraries are legacy use only, for older backups.
> 

Ahh, ok.

> > If you want to use LTFS on FreeBSD, I ported IBM???s LTFS to FreeBSD:
> > 
> > https://github.com/LinearTapeFileSystem/ltfs <https://github.com/LinearTapeFileSystem/ltfs>
> Wow, that's pretty nifty.  Thanks.
> 
> > 
> > You would need an IBM LTO-5 or newer tape drive.  LTFS is helpful, but keep in mind it isn???t a backup package in and of itself.  It doesn???t manage multiple tapes, it just gives you a filesystem on a tape.
> 
> I can see where that might be useful for restores.

Yes, it would be handy for reading one-off tapes.  For regular use, though,
you'd probably want something else.  The performance of LTFS running via
FUSE is also somewhat slow, due to the added latency of the extra trips into
and out of the kernel.

> > As for SCSI adapters, I have a several ahc(4) boards in a machine running FreeBSD/head and talking to SCSI and CD devices.  The driver seems to work fine.
> > 
> > One thing to consider if you???re switching machines and looking at buying new hardware, is whether your current tape library is still sufficient for your needs in terms of speed and capacity.  Rather than putting the money towards an LVD to HVD converter, you could put it toward a new tape drive or library.
> 
> The tape library in question is a DLT-7000, and it not used for active backups. It is retained only for older backups.
> 
> Current backups are to an LTO-4 tape library, vis a SAS2308 (Avago Technologies / LSI) card. That is working well.
> 
> I do have one M/B which has an both PCI and PCIE slots. I think the easiest short term solution is to move both cards into a chassis with that M/B. No purchase necessary.
> 

That sounds like an ideal solution for your situation.

> > 
> > Another thing to consider is using hard drives for backup.  That might work, depending on your requirements for durability and shelf life for the media.  I???m guessing that buying a number of enterprise SATA (or SAS) drives would probably be cheaper than buying even a used library, media and FC or SAS card.
> 
> I backup to disk first, then copy to tape later. Both steps are handled by Bacula, the backup package I'm using.
> 

Ahh.  If you decide to retire the tape library later on, you can always just
backup to disk and put the backup disks on the shelf.  (I've been doing
that for a long time, ZFS makes it pretty easy.)

Ken
-- 
Kenneth Merry
ken at FreeBSD.ORG