Michael Loftis <mloftis AT wgops DOT com> writes:

> --On March 2, 2007 10:31:33 AM +0000 Anthony   Worrall
> <anthony.worrall AT reading.ac DOT uk> wrote:

>> This is not strictly an amanda question but I thought I would see if any
>> one has any views on SDLT-4 compared to LTO-3.
>>
>> We are currently looking at replacing our tape devices an are looking at
>> SDLT-4 which seems to be about the same price as LTO-3 but offer twice
>> the capacity. Has anyone got any experience of these drives. I am told
>> by our supplier that they are selling many more LTO-3 than SDLT-4. Is it
>> just that SDLT-4 is newer is there some reason?
>
> SDLT-4 (DLT-S4) may cost less $/gb but it still costs more per tape.
> So unless you're actually using that much tape it may noe be as
> attractive as it seems.

In my configuration I can easily utilize 800GB tapes; so this is no
problem. I tested a DLT-S4 library and it works fine.

In Germany the tapes cost fourty percent more than LTO-3 tapes; so
DLT-S4 is less expensive than LTO-3.

> Several other issues with DLT-S4 are the relatively slow rated
> speed of 60MB/sec (LTO3 is rated at 80, and I routinely see 60 in
> production, I'd see more if I had faster hosts).

This means that DLT-S4 perfectly matches your current speed
requirements ;-)

> Also I don't know, but last I checked DLT still had to be streamed at
> the rate they were at.

Sorry, I never cared about this. Two SATA disks as RAID0 provide
enough bandwidtht.

> Though the biggest reasons LTO is outselling DLT/SDLT is SDLT is
> viewed as being end of line first,

That's IMHO the major point. There are qualified rumours that DLT-S4
will be the last in the DLT family.

> LTO-3 also has atleast one advantage for (capable) libraries, each
> cartridge has a contactless (read... RFID like) memory that can
> report the tapes last known condition, as well as user data.  in
> theory atleast an LTO drive or library has only to read this tag to
> decide whether-or-not it can read the tape, and if it even should.

Anyone ever used LTO CM (cartridge memory)? With amanda?

> DLT and SDLT have the problem that if you load an older generation
> cartridge than your drive supports you may destroy the heads.

I didn't try all combinations, but my SDLT-I drive reliably rejected
SDLT-II tapes. Nothing has been destroyed.

        Sven