Re: mdadm --monitor: need extra feature?

[David Brown <david.brown@hesbynett.no>]

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 remove hot-swap one
> drive from the array, and insert another drive. The goal is, that the
> only activity of a man is remove and insert the drive. The rest has to
> be automated.
>
> Every drive, I use for this, has prepared Raid partition and was once
> added to array, so the zero block exists and UUID is equal to the
> working array.
>
> After changing drives, the rebuilding must be initialized (mdadm -add)
>
> But first, it must be discovered, that the device with consistent UUID
> appeared in the system with degraded array and is available for us.
> After such discover, I can add the device to the degraded array and
> start rebuilding.
>
> "mdadm --monitor" can recognize that a drive disappeared, but it can't
> recognize, thant a drive with consistent UUID appeared!
>
> Or maybye I am wrong and I didn't understand something from mdadm and
> mdadm.conf?
>
> Now I use for this my own script in crontab and i don't use "mdadm
> --monitor" at all because it only partially do what I want.
>
> My question is: Is it possibe to recognize with "mdadm --monitor" that
> the new device with consistent UUID appeared? Or if no, do You mean,
> this feature is worth to implement?
>
> Sergiusz
>
> ps.
>
> sorry for my english :)
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>

--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html