Re: ufsdump & tape capacity

From: Jay Lessert (jayl-news_at_accelerant.net)
Date: 10/27/04 

Date: 26 Oct 2004 18:59:41 -0700

Julian Thomas <julian.thomas@t-online.de> wrote in message news:<clb158$n5$03$1@news.t-online.com>...
> Yes ;) I want to backup lots of jpgs, 10 Gbyte of images,
> nothing else.

JPG format is already compressed far better than the modest
compression hardware/firmware in your drive. If compression
is in fact enabled, then your drive will attempt to recompress
the already-compressed data and will actually GROW the data
size.

It sounds like that is happening (i.e., only 10GB of data on
a 12GB tape).

Find out what the non-compress device is for your system.
Probably /dev/rmt/0l. Use that, and I bet the 10GB will
fit.

However, you're right at the edge of capacity in any case;
why not just use two tapes, as ufsdump is already offering
to do for you? The tapes are (reletively) cheap...

FYI, more sophisticated/recent drives (LTO for sure, SDLT I
think) will autodetect pre-compressed data streams and decline
to recompress the data. But that's way more expensive hardware
than you're interested in at the moment...

-Jay-

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