[sf-lug] Backups are important

Rick Moen rick at linuxmafia.com
Wed Nov 21 03:30:05 PST 2007

Quoting Asheesh Laroia (asheesh at asheesh.org):

> I don't know of a situation where both of these are true: 1. The backup 
> drive is not damaged, and 2. You cannot read the backup drive with the 
> same software that created it on a different computer; given also 3. The 
> backup drive is software-wise and hardware-wise compatible with the new 
> machine (which is true for e.g. ext3 filesystems stored on USB disks that 
> will be read by systems running some modern Linux system on some modern 
> PC).

It's really late and I'm really tired, but I'm having a difficult time
parsing the above, and figuring out why it makes it untrue that, e.g.,
making me use X11 to restore a headless server -- or merely to restore
my laptop from tape, or to restore a little WAP box with 32MB total RAM
-- is wasteful in requiring the use of otherwise pointless hardware
and/or software.

> You would have to install "additional...software" on the someone else's 
> computer, in this case TimeVault, it's quite true.  You could do that from 
> a live CD, I suppose, and install it to the ramdisk, if you wanted 
> to avoid touching the other guy's hard disk.

I should have to fire up X11, gtk2, and a bunch of gnomelibs _just to do
a restore_?  Wow.  Sorry, I don't think that's reasonable, and, even if
it's feasible some of the time, I strongly suspect I'd end up at some
point being tempted to LART the designer out of sheer frustration.

> You're a professional.  This isn't the right solution for you.  I'm not 
> really suggesting it for you.

When I was a novice, I didn't like my time being pointlessly wasted
then, either.  ;->

A nice little ncurses-driven menued utility is just about exactly right
for a restore routine, I've found.

> Here's the thing: WHile it's a two-hour minimum for each machine for you 
> to waste time with these GUI backup tools' long dependency chain, it's a 
> probably at least a one-month job to teach solid command-line 
> understanding to someone lacking the kind of experience we have.

Are you _sure_ you don't need some help beating all those straw men you
keep hurling out?  I mean, *I* can tell the difference between "boot a
CD, it enters directly into an ncurses-driven rootine that asks you a
couple of questions and retores your data" and "a one-month job to
teach solid command-line understanding".  Are we supposed to believe
you don't?

> So I *am* suggesting it for a different userbase than you: namely, people 
> who haven't undergone that long training process that results in grokking 
> command-line thingamabobs.

Wow, you _do_ need help whacking those straw men!  It's likely to become
a full-time job.

> What I meant was, what's wrong with *requiring* a GUI for some backup 
> tools?

I did my best to be clear.  If I didn't succeed, then I'm obliged at
this point to give up.  Sorry.

> That seems to me to contradict your claim.

Nope.  The RAM, hardware, time, and sheer bloat of having to fire up,
e.g., GNOME (or at least X11, gtk2, and gnomelibs) just to run a
friggin' restore are from my perspective a dead loss -- especially when
compared with the results from using tiny, commodity tools that don't
require that.

> Every night a backup job runs that backs up the whole filesystem for 
> filesystems I care about.  (It uses incremental storage via hard links.) 
> Once that completes, the system removes any backups that are more than a 
> week old, except if by removing that job the system would remove the last 
> existing backup.  This means that during normal system operation I can go 
> back as little as a day and as much as a week, and I can always get the 
> latest backup if it's older than a week.

Again, I'm more than a little tired.  How many generations of backup do
you keep, then?

> As for "distant", the backups of the machine in my parents' basement (in 
> Rochester, NY) are stored in Tokyo; the machine in Tokyo is backed up to 
> San Francisco; the machine in San Francisco is backed up to somewhere else 
> in San Francisco.

So, the reason I ask about number of generations and offsite versus
onsite locality is that it's often prohibitive of bandwidth, in
practice, to do timely ongoing backups with a reasonable number of
generations retained, across commodity home broadband links.  Sometimes
yes, sometimes no.  I'm glad it works for you, regardless of details.
As I said, I like rsync quite a bit.

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