Don't know if its relevant, but I've got an LTO5/juke and it
dropped in both speed and capacity. I'm now trying to remember
if I had the host ESAS card replaced, or the I/O module in the
juke...
On Wed, Mar 12, 2014 at 12:28:33PM -0400, Jon LaBadie wrote:
> On Wed, Mar 12, 2014 at 02:38:48PM +0000, Dave Ewart wrote:
> > Hello,
> >
> > Four years ago I deployed a pair of Tandberg LTO-5 Ultrium (SAS) tape,
> > connected a Dell PowerEdge server via a Dell H200 SAS controller.
> >
> > At that time ran the amtapetype utility which produced this output:
> >
> > define tapetype Tandberg-LTO5 {
> > comment "Tandberg LTO5 1500/3000, produced by tapetype prog (hardware
> > compression off)"
> > length 1410 gbytes
> > filemark 0 kbytes
> > speed 125762 kps
> > }
> >
> > (That was created by an older version of AMANDA, which we were using at
> > the time: probably from Debian/Lenny, which was version 2.5.2p1, I
> > believe)
> >
> > These tapes are native 1.5TB and so that looks pretty reasonable. We've
> > never used these tapes to their fullest capacity and all was fun and
> > shiny until recently when the tapes reported "No space left on device".
> > However, the concerning thing is that the tapes reported 'full' at less
> > than what I was expecting as full capacity, just above 1.1TB in fact.
> > This means that our backup space 'growth', which I had been assuming was
> > only 75%/80% full is in fact at 100%!
> >
> > I re-ran the tapetype utility from our current AMANDA (version 2.6.1p2-3
> > from Debian/Squeeze) and it showed this:
> >
> > define tapetype unknown-tapetype {
> > comment "Created by amtapetype; compression disabled"
> > length 1148746080 kbytes
> > filemark 0 kbytes
> > speed 69815 kps
> > blocksize 32 kbytes
> > }
> >
> >
> > The length reported here is ~1.1TB which ties up with the "no space left
> > on device" message, but ...
> >
> > ... these are genuine LTO-5 (Tandberg brand) tapes - just like
> > http://img.misco.eu/Resources/images/Modules/InformationBlocks/1210/TAN/TAN-2/202175-tandberg-LTO-5-tape-cartridge-small.jpg
> > - and the second tapetype above was created using a previously-unused
> > tape and they really are 1.5TB native!
> >
> > What's going on? Why am I not getting to use the full capacity??
> >
>
> A guess only.
>
> I note the measured speed has dropped by 45%. Due to what I haven't a clue,
> but maybe some hardware change or cables or ???
>
> Perhaps your system's ability to feed the drive has dropped below the
> minimum needed to keep the drive streaming. In that case, the drive
> must "shoe-shine" and each restart costs a bit of tape.
>
> Jon
> --
> Jon H. LaBadie [email protected]
> 11226 South Shore Rd. (703) 787-0688 (H)
> Reston, VA 20190 (609) 477-8330 (C)
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