[TAG] Backup Strategy

[Jim Jackson]

On Fri, 19 Mar 2010, Ren? Pfeiffer wrote:

> On Mar 19, 2010 at 2209 +0100, Karl-Heinz Herrmann appeared and said:
>> On Sun, 7 Mar 2010 02:53:20 +0530
>> Amit Saha <amitsaha.in at gmail.com> wrote:
>>
>>> I am going to use it as a dedicated backup drive. Thanks in advance!
>>
>> [...]
>> With that amount of data you do want protection against single disk
>> failure. So if the primary disk is not already a raid system you should
>> make the backup a raid 1 or 5.
>
> Don't use RAID5 with disks containing a large block number. The
> probability for a double-disk failure gets higher with the amount of
> blocks.
>
> http://www.tomshardware.com/news/RAID-5-Doomed-2009,6525.html

I think you will find, if you read all the comments on this article,
that many people, who appear reasonably knowledgable, think this is 
bullshit^H^H^H^H^H^H^H^Hfanciful.

Given the article was written in 2008 and disks have indeed got a lot 
bigger, and are used in large raid5 arrays, I think we'd be hearing a lot 
of squealing in the industry right now!

> http://en.wikipedia.org/wiki/Standard_RAID_levels#RAID_5_disk_failure_rate
>
> Consider RAID6 or using RAID1 block devices as building blocks for
> logical volumes.
>
> Best,
> Ren?,
> jumping to mention this, no harm intended. :)
>
>