[clug] LTO-4 drive, turn on compression?

[Chris Smart]

2009/8/11 Daniel Pittman <daniel at rimspace.net>:
> Chris Smart <mail at christophersmart.com> writes:
>
>> Anyone know how to turn on compression on an LTO-4 tape drive?  Have tried:
>> mt -f /dev/nst0 compression 1
>> But that didn't work. The man page is not super helpful and my Google-fu sucks.
>
> That should be it, sorry.  There isn't anything else *standard* to turn on
> compression.  (Although the 'default compression' option /might/ be worth
> checking, just in case...)

The man page doesn't tell you what argument "compression" takes. It
just says to use it to turn compression on or off. Helpful!

It also doesn't provide any feedback to tell you if it worked, failed,
or even tried. For all it cares, you can pass:

mt -f /dev/nst0 compression banana-peels

:-)

>
>> I have a Quantum SAS connected LTO-4 drive which works a treat, but
>> I'd like to backup more than 800GB onto a single tape.
>
> Personally, my strong preference is to do the compression in software rather
> than rely on the drive.  There is nothing like discovering that the one tape
> drive that just failed was the /only/ one that can manage to decompress the
> tapes it wrote, for some crazy reason.[1]

I'll do this, I was just wanted something quick and non-resource
intensive. The files are all text, so it should compress down nicely
with software.

>
> LTO tapes are better, in my experience, than the crappy old standards, but
> I am still nervous about it all, and prefer to stick with software
> compression.  (Typically, only LZO compression, because it is very fast and
> reasonably effective.)

They sure are :-) I'll give lzo a try, thanks.

-c