Re: mdadm --monitor: need extra feature?

["Sergiusz Brzeziński" <Sergiusz.Brzezinski@supersystem.pl>]

W dniu 21.08.2012 12:44, David Brown pisze:
> On 21/08/2012 12:41, Sergiusz Brzeziński wrote:
>> Hi,
>>
>> I use Raid1 to make backup of the whole system.
>
> Raid is not a backup system. It is to improve uptimes, minimise downtimes due to
> disk failures, and possibly to improve disk speed and/or capacity.
>
> I would recommend you first think about what you are trying to achieve here -
> what are you trying to back up, how do you see restores being used, how
> efficiently are you using your hardware, your bandwidth, your time and effort?
>
> You would probably be better off with a normal fixed 2-disk raid1 to minimise
> the problems caused by a single disk failure, combined with an rsync snapshot
> style backup that can be fully automated and give quick and easy recovery of
> multiple old versions of files in the face of the most common cause of data loss
> - human error.
[...]

I know, I know. Raid is not a backup system :)

Or better: it is not intended to be a backup system.

But I do use Raid1 as backup solution because I don't know another backup 
solution giving me together:
- so simple configuration (there is no configuration!)
- so low cost (no software cost, only hdd cost)
- complete copy of the whole system (not only data but also configuration)
- so quick start in case of hardware failure
- so fast backup process without excessive system load
- so simple handling (just remove and insert hdd with hot-swap bay)

With some more rotating disks it can simulate very good backup solutions and I 
still can make backups of critical data (dumping databases, copying files) 
independently of Raid (and I do it).

And even I You don't want using it as a regular backup it is alwas worth to do a 
bootable disk with mirrored system partition and keep it somewhere out of the 
box for the bad times - just a small system backup for quick start in case of 
hardware failure.

So, maybye Raid 1 is not a backup system but for some cases this is the best 
backup solution it can be! And I am an opportunist :)

Sergiusz

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