Re: Backup

[Phil Dobbin <bukowskiscat@gmail.com>]

Gary Dale wrote:

> On 17/08/12 02:25 PM, Glenn English wrote:
>> On Aug 17, 2012, at 10:53 AM, Camaleón wrote:
>>
>>> On Fri, 17 Aug 2012 03:40:41 -0500, Emil Payne wrote:
>>>
>>>> I have a 1 TB external USB drive with 362 GB used. I'd like to do a
>>>> full
>>>> backup to DVDs and then an incremental (or something) backup every
>>>> month
>>>> or two, also to DVDs or CDs. I'd like the backups to be compressed in
>>>> order to save space (i.e. - the number of DVDs/CDs used).
>>> Optical media storage is a PITA for big amounts of data (it's very slow
>>> and hard to manage when you intend to do rewrite operations).
>> I really hate to be the old fogey here, but if you've got the $$, tape
>> sure does a good job. Use Amanda for both incrementals and fulls, and to
>> reduce PITA, get cron to run them overnight. Or over the weekend, if you
>> want to backup a lot of data, but infrequently.
>>
>> Optical disks and hard disks don't last. I have audio tapes from the
>> 1950s
>> that are still good. Tape has its disadvantages, but longevity isn't one
>> of them...
>>
>> For backup, though, I'd suggest springing a little more media and telling
>> Amanda to write uncompressed tarballs -- for reliability and ease of
>> recovery
>> from a major disaster. You can recover from an Amanda backup tape with
>> nothing
>> more than plain old tar. A major PITA, but it's possible.
> 
> While tape has uses, it's not all that reliable. Tape is subject to
> chemical deterioration, magnetic drop-outs, stretching, and a host of
> other problems. You won't notice the problems so much on audio tape with
> a lot of tape surface to hold the music (1/2 inch open reel audio tapes
> from the 1950s are more reliable than cassettes from the 1970s).
> However, on data tapes, the problems start showing up fairly quickly.
> 
> It's main advantage over the years has been capacity. A automatic tape
> library can hold a lot of data over multiple tapes. However, tape
> changers are expensive, as are the media.
> 
> You're correct about not compressing the data. Uncompressed tars are
> less prone to catastrophic failure from data dropouts. However, this is
> less of an issue with optical media. Still, I always do a cmp after
> backing up to optical media just to ensure the data actually copied
> correctly. If it didn't, I rsync and cmp again.

If you were to forgo tape as an option, I could recommend luckybackup
(it's in the current Squeeze repos).

I stumbled across it after I found when upgrading to Fedora 17,
mondoarchive no longer worked so that left me looking for something else
to use for local backups (I use rsync for remote ones) on Fedora.

It's basically a frontend for rsync that does incremental backups,
snapshots, etc & it really is more than adequate. I've checked the
restore function & that worked fine, so all in all it does the job that
I ask of it very well. YMMV.

Cheers,

  Phil...

-- 
currently (ab)using
CentOS 6.3, Debian Squeeze, Fedora Beefy, OS X Snow Leopard, Ubuntu Precise