Re: [gentoo-user] backup hardware setup

[thegeezer]

On 06/24/2014 03:43 PM, meino.cramer@×××.de wrote:
> Hi,
>
> I bought two identical external harddrives, USB 3.0, with 1 TByte each
> (no SSD - the good ole mechanical ones...;).
>
> The intended use is for backup of longer files. The drives will
> contain the same contents.
>
> Currently there are still "clean metal" (no partitioning, no fs).
>
> Data integrity and recoverability (Uhhh...that words looks wrong...) in
> case of an desaster is more important than speed.
>
> What is the recommended way of partitioning ?
> What filesystem to choose?
>
>
> Thank you very much in advance for any help!
> Best regards,
> mcc
>
>
> PS: Running vanilla kernel 3.15.1....
>
>
>
>

I do this using hard links and rsync to only copy changed data.
this creates a dated folder structure that i can then rsync / cp using a
livecd to baremetal and basically allows best recoverability, imho.
so long as the filesystem supports hard links you are golden.
you might want btrfs for this for long term storage to help in case of
bitrot, but rsync should refresh the file if it is suddenly unreadable
(meaning any other hard lnked versoins are also up the swanny)
ymmv depending on what it is you are backing up

#!/bin/bash
echo 'preparing..'
date=`date "+%Y-%m-%d_%H.%M.%S"`
workingfolder="/mnt/usb/backupsyncs/myhost1"
fromfolder="root@myhost1:/* --exclude=/var/tmp --exclude=/dev
--exclude=/mnt --exclude=/opt --exclude=/proc --exclude=/sys
--exclude=/usr/portage --exclude=/usr/src"

echo "Date " $date
echo "From " $fromfolder
echo "To   " $workingfolder

echo "move current to be dated"
mv $workingfolder/current $workingfolder/backup-$date

echo "now syncing into dated folder"
rsync -vz --partial --modify-window 5 -W --delete -a $fromfolder
$workingfolder/backup-$date

echo "cleaning up..linkcopying dated folder to <current>"
cp -al $workingfolder/backup-$date $workingfolder/current