Re: [gentoo-user] Backup questions

[Dale]

Wols Lists wrote:
> On 08/08/18 04:43, Dale wrote:
>> Howdy,
>>
>> I just bought two external drive enclosures.  One is sort of a spare but
>> I do plan to do some backups on it, mostly pictures from my camera.  In
>> one of the enclosures I put a single 6TB drive that I found on ebay.  It
>> has about 7,000 hours on it so it should have some life left yet and it
>> passed the smartctl tests.  It is USB but it transfers fast.  Now to
>> some questions.  I use rsync.  Command looks something like rsync -auv
>> /source/ /destination/.  If I backup the config files in my home
>> directory, should I also include the --delete option?  If after a
>> upgrade for example a config file is deleted, because it is no longer
>> needed, or renamed, should the old file be removed or is there a reason
>> to keep them on the backups?  Adding the --delete option isn't a problem
>> command wise BUT I wonder if it can cause a problem at some point.
>> Thoughts on that.  I plan to use the --delete option for videos since if
>> I deleted one, it is likely broken or something.  Biggest question is
>> about config files.
>>
> May I suggest using btrfs for your backup drive? One MAJOR caveat - DO
> NOT let the drive fill up - a combination of snapshots and drive-full
> has been known (quite often) to trash the file system. But provided you
> make sure it doesn't go above about 80% you should be fine.
>
> You can add an option to rsync such that it will back up "in place". In
> other words, if only 1K is changed in a 1M file, it will overwrite that
> 1K. So when you back up, the procedure is to take a snapshot, then run
> rsync with both "in place" and "delete".
>
> This will give you the space economy of incremental backups, combined
> with the utility of full backups - each snapshot is a full backup as of
> that date, but each new snapshot only increases disk usage by the
> changes since the last. And you reclaim space by deleting old snapshots.
>

I did think about btrfs.  I've read a lot of threads on here about
people using it and it seems to have come a long ways and be pretty
stable.  Right now, I've got a lot going on and really don't have the
time to sit down and read up on it and how it works or what all it can
do.  In all honesty, if my system were to crash later when I don't have
so much going on, I'd like to move to btrfs for as much as possible of
my system.  I suspect /boot would still have to be ext2 or something
because of grub. 


>> On the second enclosure I currently have a 160GB drive.  It's big enough
>> for my camera pictures.  I would like to backup up my pics to it and
>> then put the drive somewhere besides in the house.  I have a couple
>> external buildings that would be safe as far as rain etc but they are
>> not cooled, even tho it gets close to 100F and humid, real humid, here.
>> My question is this.  Is it safe to store a drive in that sort of
>> environment?  I could see the building getting close to outside temps
>> during the day.  I do put a heater in it to prevent freezing during the
>> winter.  I usually set the heat to 40F.  I'm hoping someone has some
>> real world experience on storing in this sort of environment and not
>> just a text book theory.  One reason I want to put them elsewhere, house
>> fire.  Even a huge power strike could cause problems if plugged in.  We
>> do get lightening strikes here.  Maybe not as many as some but our fair
>> share.  The 6TB and 3TB drive may join this one as well.
>>
> A drive that's shut down will take more mistreatment than one that is
> running. So no worries on that score. Plus heat causes far less problems
> than people think, although yes it's best avoided.
>
> Do your outbuildings have power? Do you have a fridge (or possibly
> freezer) out there, or could you find an excuse for one - a wine-store
> maybe :-) What you really want is some form of insulation that will
> prevent rapid fluctuations in temperature, and sticking your drives (in
> sealed bags) in a wine fridge would probably be near ideal. I had a
> cellar for my wine, and daily fluctuations were near nil even though
> there was a maybe 20C variation between summer and winter. That's what
> you want to aim for. Or maybe if you can dig a mini-cellar in one of
> your outbuildings :-)
>
> Cheers,
> Wol
>

I've read the labels in the past.  They can handle more when not powered
up so you are right there.  I was just curious if someone had real world
experience with such conditions.  The past several days it has been
pretty hot and humid here.  If I think about it, I'll try to go to the
building and take some temps and check the humidity.  I think I have a
humidity meter out there, it's with the temp meter I think.  I know in
the past I've seen it be over 90F in there.  For what is usually stored
in there, I don't worry about heat as much as I do cold.  Some things in
there can't freeze.  The drives are what makes me consider the heat.

I do have some foam coolers I could put them in.  I was also planning to
buy some of those thick bags to put them in while in the house then take
the sealed bag drives to the building.  Then later on when I need the
drives, I could bring them in, let them sit overnight or something if
needed and then remove them from the bag and plug in to use.  I could
also add a couple desiccant bags or something to those bags.  The
biggest thing is avoiding condensation if it is cold out there and warm
in here.  The bags I'm talking about is those vacuum bags like people
put clothes in.  They are pretty thick and tend to work pretty well.

It has power.  I'm not sure where I'd put a fridge, even a tiny one.  I
wish it was twice as big as it is.  Of course, I'd fill that up in no
time too.  Isn't that the way it works?  ROFL 

I'm getting interesting ideas tho.  Pondering that backup software
option too.  It has its pluses.  ;-)

Thanks.

Dale

:-)  :-)