On Tuesday 05 September 2006 10:10, Geert Uytterhoeven wrote:
>On Tue, 5 Sep 2006, Gene Heskett wrote:
>> On Tuesday 05 September 2006 05:24, Geert Uytterhoeven wrote:
>> >On Tue, 5 Sep 2006, Phil Howard wrote:
>> >> On Sat, Sep 02, 2006 at 06:39:40PM -0400, Jon LaBadie wrote:
>> >> | It certainly would destroy one of amanda's features,
>> >> | the ability to easily recover backup data using
>> >> | standard unix utilities without amanda software.
>> >>
>> >> How is that destroyed?
>> >>
>> >> Suppose you use tar format. You can have tar read from tape
>> >> directly, which is what I presume you mean for being able to recover
>> >> outside of Amanda. You can have tar read from disk partitions if
>> >> the native partition scheme is used.
>> >
>> >At first I had the same reaction as you: it would work fine if you
>> > would cycle your tapedev through the partitions. However, then I
>> > realized a tape can store multiple `files' sequentially, while a disk
>> > partition can't (without hackerish that would annihiliate the easy
>> > recovery again).
>> >
>> >So as long as you dump only one DLE, it would work fine. If you dump
>> > more than one DLE, you need more logic.
>>
>> I don't know how this conclusion was reached, but IMO its wrong.
>> One of the beauties of amanda is that bare metal recoveries can be done
>> with nothing more than dd, tar(or dump if that what was used) and gzip.
>>
>> Its far more trouble to locate a file you want on a sequential tape
>> than it is to locate it in a vtape. The vtape itself is nothing more
>> than a subdir in a subdir in the filesystem of the hard drive.
>> Switching the vtapes is as simple as replacing the link to the
>> directory called data, with a new link named data that points at the
>> desired directory.
>
>Yes, that's true. But this discussion was about using raw partitions on a
> disk instead of files on a filesystem on a disk.
Not workable at all IMO. You cannot just willy-nilly rewrite the partition
table if you don't want to lose ALL the data in the next higher partition
and all those above it. If that was the only partition, and you were
using the disks as tapes, meaning that for 20 'tapes' you'd have to have
20 disks in carriers, then I assume it could be made to work. The only
place I might be able to see a speed advantage is where the individual
dle's were less than 1k in total size as you would be skipping the file
opening and closing housekeeping along with the allocation searches. But
as I point out in another post, disk speed, at least for me, is not a
factor to consider as its many times faster than some of the other
operations, like compression. And my storage disk is slow, only a 7200
rpm'er.
>Gr{oetje,eeting}s,
>
> Geert
>
>--
>Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> geert AT linux-m68k DOT org
>
>In personal conversations with technical people, I call myself a hacker.
> But when I'm talking to journalists I just say "programmer" or something
> like that. -- Linus Torvalds
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
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message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.
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