Hi,
this stupid argument rears its head again - snapshots vs "backups".
At least now someone advocating time-consuming "backups" has come up with a
logical argument - You "usually" put the system into a static state before
performing a "backup".
Trouble is - the "backup" usually means your system is down (e.g. in single
user mode) for as long as it takes to perform the "backup".
A snapshot on the other hand can be validly performed (on a mirrorred file-
system by shutting apps down (going to single user mode/rebooting) detaching a
mirror, bringing your system back online immediately (resyncing to a new
mirror) then (if you so wish!) performing a normal "backup" of the detached
mirror - or (if you simply don't run database apps or such like) simply
stashng the detached mirror away as todays "backup".
Expect lots of flack from keen "backup"! fans here.
KInd Regards
Andy
On Tuesday 11 August 2015 19:52:02 Diogene Laerce wrote:
> Hi Rick,
>
> Le 11/08/2015 19:18, Rick Stevens a écrit :
> > On 08/11/2015 09:18 AM, Chris Murphy wrote:
> >> On Tue, Aug 11, 2015 at 3:05 AM, Diogene Laerce <me_buss...@yahoo.fr>
> >>
> >> wrote:
> >>>> https://wiki.archlinux.org/index.php/Full_System_Backup_with_rsync
> >>>
> >>> Is there a trick I don't see here ? Because if the backup of those
> >>> directories
> >>> is enough for a full restoration of a system state, this method is
> >>> far more
> >>> efficient than the others, isn't it ? As one does not need to reboot
> >>> and
> >>> just have
> >>> to make a script or/and a cron job to make his own snapshot.
> >>
> >> I don't consider a backup and snapshot to be the same thing. Copying
> >> (or rsyncing) some directories to another volume is a backup. A
> >> snapshot is a deduplicated copy of something at a particular moment in
> >> time, on the same volume or storage pool. It's not a backup, in that
> >> if the pool implodes both the original and snapshot are lost. A
> >> snapshot can be used as a source for a backup, since you can make a
> >> snapshot that doesn't change while the backup is happening.
> >
> > I agree with Chris. Snapshots are ways of restoring data that has been
> > perhaps corrupted or deleted or going back in time to some earlier
> > point in the filesystems' life. They aren't backups.
> >
> > Backup philosophies and techniques vary depending on what you need for
> > your unique situation. I'm not claiming what I do is the best, but this
> > is what works for me:
> >
> > On the last Friday of a month, I plug in a big ESATA or USB3 drive and
> > use it to store the output of Mondo Rescue. I have the backup in the
> > form of DVD-sized ISO images I can burn DVDs from and there is a
> > recovery DVD you can boot from. That gives me a backup usable to
> > restore to bare metal.
> >
> > Once a week (or more often if there's been significant changes), I use
> > a _different_ ESATA or USB3 drive and run an rsync that backs up
> > everything except a few things (/proc, /sys, /dev, /media,
> > /var/log/journal, various caches, etc.) to a directory on that external
> > drive based on the hostname and date I ran the backup. That permits me
> > to restore data that's a bit more recent than the MondoRescue stuff.
> >
> > I'd be happy to share the MondoArchive and rsync scripts if you wish.
> > Tweak to suit your needs.
>
> Thank you for the offer.
>
> I'm going to stick with RedoBackup but I'd really like to have a look at
> your rsync scripts, and maybe at what various caches you think of.
>
> Kind regards,
--
users mailing list
users@lists.fedoraproject.org
To unsubscribe or change subscription options:
https://admin.fedoraproject.org/mailman/listinfo/users
Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct
Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
Have a question? Ask away: http://ask.fedoraproject.org
