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Re: Recommended Linux Backup



Tony Nelson wrote:

> On 09-11-01 02:01:18, lrhorer wrote:
>> > I don't see any mention of that venerable *nix utility, dump.
>> > Other than not looking like a mounted filesystem and possibly the
>> > sheer size of the data, dump should fulfill your requirements.
>> 
>>         I thought about dump, but I did notthink it would stop when a
>> volume is full and prompt for another volume (at least not if the
>> volume is a hard drive).
> 
> dump normally stops when the media is full (see `man dump` for details
> and other options), and can either just pause or run a script.  I back
> up semi-manually to DVD via a temporary file, with this command:
> 
>     # dump -0 -L xxx -b 32 -B 4590200 -f /tmp/dvd /mnt/point
> 
> -0  Full dump
> -L  Label
> -b  Blocksize
> -B  Set the size of the output "tape"
> -f  Output file

        Well,OK.  Still, dar better suits my requirements.
  
>> > You'd certainly want to rotate between several dump sets for
>> > redundancy.
>> 
>>         No, I'm gong to be doing differential backups. The bckuip
>> array added tot he offline storage is enough redundancy.
> 
> Well, if you say so.

        There is no such thing as too many backups, but yes, I have enough
redundancy.


>> > That would mean more hard drives.  It might make sense
>> > to also dump to DVDs, just to have a different failure mode.
>> 
>>         You're kidding,right?  Back up the data to more than 900 Dual
>> Layer DVDs?  Admittedly they are cheap, but... no, thanks.
> 
> It depends on the consequences of data loss.  If they are severe,
> there should have several live copies at different locations and
> providers or at least two offline copies, preferably one with

        Then I would use multiple hard drive sets.  Hard drives cost as little
as $.073 per Gigabyte, can read and write upwards of 75 MB/sec, and can
store up to 2 TB (soon 3 TB) in a space 1" x 3.5" x 6".  By comparison,
DVDs cost about $.11 per Gigabyte, usually cannot read or write more
than 10 MB/sec, and take up easily 5 or 6 times the space per Terabyte.

> completely
> different failure modes.  On the other hand, if data loss is of little
> consequence, then sure, one copy is enough.

        You aren't reading what I am writing, and are assuming much.  First of
all I already have at least TWO copies of all my data, even the least
significant.  Both of these copies are on fault tolerant RAID arrays. 
Secondly, any more than ordinarily important data is also backed up
with multi-generation copies on local hard drives.  All critical data
is stored in no fewer than four geographically diverse locations.  This
backup strategy will simply augment an already robust set of backups,
and provide geographic diversity for the individually less important
but massively voluminous videos on the arrays.


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