The script would take a little tweaking, but it could work.

I, personally, know that I would get lazy at some point and fail to swap
the drives for months on end. I would consider taking one of the drives to
both locations, and getting an initial backup of each location, and then
mirroring that to the other drive -- and then have both locations back up
to both drives. Alternatively, you could backup both drives to the local
drive, and then mirror the two drives(you could do hourly local backups,
and nightly remote copies). Since rsync only transfers the differences,
once you have the initial backup, it's likely that each day's change is
fairly small. If you use the flag to make rsync aware of the hardlinks, you
could presumably replicate a full copy of the day's hourly backups fairly
quickly.


On Fri, Sep 4, 2015 at 2:17 PM, Mike Miller <mbmiller+l at gmail.com> wrote:

> That is really cool!  I'll have to try something like that. I'm thinking a
> good strategy is to have two drives, both with all the same stuff on them,
> and I'll use them both to backup all my Linux boxes (home, office,
> laptops).  I'll just switch between home and office every week or so. That
> way if my house burns down or my office is burglarized, I still have a copy
> of everything from last week at the other location.
>
> Does that seem reasonable?  The thing I'm not sure of is how that strategy
> would work with the "time machine" concept -- I'd be using two drives and
> swapping them weekly.
>
> Mike
>
>
>
> On Fri, 4 Sep 2015, Jeff Chapin wrote:
>
> Looking at the rsync command you gave, it looks correct -- but rsync can do
>> so much more when backing up!
>>
>> Using the magic of rsync, and the magic of hardlinks, you can make a full
>> backup, in incremental time and space. Rsync has, built into it, the
>> ability to compare your most recent backup files with existing backup
>> files, and if they are they same, use a hard link, and copy them over if
>> they differ. This allows you to store just the files that change -- but it
>> looks like a full backup every time it runs. This way, you can keep, say,
>> hourly backups for the last week -- and recover an accidentally deleted or
>> altered file, even after the latest backup has run.
>>
>> For more details:
>> https://blog.interlinked.org/tutorials/rsync_time_machine.html
>>
>>
>>
>> On Fri, Sep 4, 2015 at 8:21 AM, T L <tlunde at gmail.com> wrote:
>>
>> Assuming that you have NOTHING on the drive that you care about, I would
>>> remove the factory partitioning and create a new GPT table with parted.
>>>
>>> Then, format that as ext4.
>>> On Sep 3, 2015 3:17 PM, "Mike Miller" <mbmiller+l at gmail.com> wrote:
>>>
>>> How to format?
>>>>
>>>> I have a couple of Linux boxes that I would like to regularly backup to
>>>> a
>>>> 5 TB external drive.  It seems like it would be a good idea to format
>>>> that
>>>> drive with ext4.  Can I just do that with gparted?  The drive comes with
>>>> NTFS format.  Are there any issues I should know about?
>>>>
>>>>
>>>> Which directories to back up?
>>>>
>>>> What really needs to be backed up?  I guess if the system totally failed
>>>> I'd install Linux (Ubuntu) again.  Of course /home is needed, but
>>>> /usr/local and /opt often have programs I've installed and /etc will
>>>> have a
>>>> bunch of settings.  I guess /var can have some important stuff.  Are
>>>> crontabs stored in /var?
>>>>
>>>>
>>>> Which software to use for backup?
>>>>
>>>> I guess I want only to have in backup what is on the originating drive.
>>>> So if I have deleted a file, I want it to be deleted on the backup
>>>> drive,
>>>> too.  I assume rsync can do this.  Would this be correct?:
>>>>
>>>> rsync -av --update --delete /home /usr/local /etc /var /opt
>>>> /media/me/back
>>>>
>>>>
>>>> TIA!
>>>>
>>>> Mike
>>>> _______________________________________________
>>>> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
>>>> tclug-list at mn-linux.org
>>>> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>>>>
>>>>
>>> _______________________________________________
>>> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
>>> tclug-list at mn-linux.org
>>> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>>>
>>>
>>>
>>
>> --
>> Jeff Chapin
>> President, CedarLug, retired
>> President, UNIPC, "I'll get around to it"
>> President, UNI Scuba Club
>> Senator, NISG, retired
>>
>> _______________________________________________
> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
> tclug-list at mn-linux.org
> http://mailman.mn-linux.org/mailman/listinfo/tclug-list
>



-- 
Jeff Chapin
President, CedarLug, retired
President, UNIPC, "I'll get around to it"
President, UNI Scuba Club
Senator, NISG, retired
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.mn-linux.org/pipermail/tclug-list/attachments/20150904/bc972d34/attachment-0001.html>