Re: [gentoo-user] backup to a cold-swap drive

[Iain Buchanan]

On Fri, 2010-04-30 at 16:24 +0200, Florian Philipp wrote:
> Am 29.04.2010 02:38, schrieb Iain Buchanan:
> > Hi & thanks,
> >
> > On Wed, 2010-04-28 at 17:31 +0200, Florian Philipp wrote:
> [...]
> >
> >> If you can live with just one big partition as a backup (probably with
> >> separate /boot), you should replace fstab and grub.conf on the backup
> >> medium and blacklist them from the files which you want to back up.
> >
> > why wouldn't I backup fstab and grub.conf as well?  If my internal disk
> > dies, I assume I'll swap them over, meaning grub and fstab will have to
> > be the same.
>
> I think you misunderstood me or I didn't explain it correctly. I try it
> again:

[snip]

ah, NOW I get it :)

[snip]

> Ah, I see what you mean. I've never worked with the file alteration
> monitor (FAM) but once evaluated inotify for some administrative
> purposes. AFAIK they are not scalable good enough to work on a system
> wide basis. For example, I think the default limit of observable files
> with inotify is 8192.

hm, there goes that idea!  Is there any kernel based "watch" on all file
based I/O that I could queue up somehow?  Just thinking aloud here.  I
know "everything is a file", but no doubt I could watch all write
operations; filter out /dev and put the rest into a file; and then use
it like an rsync file-list...

> > thanks for the tips :)  rsync will at least get me going quickly.
> > Yesterday I tried iotop to with dd - some slowness but otherwise quite
> > nice.
> >
>
> To reduce the performance impact, you can also use the ionice command.

whoops, that's what I meant.  Even with ionice, there was some
noticeable delay when switching screens, opening programs, etc.  More so
when my RAM had been swapped from the large amount of I/O (I assume).  I
didn't try ionice with nice.

thanks,
-- 
Iain Buchanan <iaindb at netspace dot net dot au>

One family builds a wall, two families enjoy it.