Cheapest way to backup data

[mark-OGhnF3Lt4opAfugRpC6u6w at public.gmane.org (Mark J. Dulcey)]

100ji wrote:
> On Sun, Feb 22, 2009 at 12:07 PM, Richard Pieri <richard.pieri-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org>wrote:
> 
>> On Feb 21, 2009, at 1:34 PM, 100ji wrote:
>>> 1) having your own raid.
>>> 2) Store it on the cloud.
>>> 3) Pool free storage (gmail, free online storage etc..)
>> RAID isn't data integrity.  It is media integrity.
>>
> 
> Hmm, is this the property of all raid levels though?

I think that what he means about RAID not being data integrity is that 
data can still be damaged by malfunctions in the computer and/or OS; 
that will typically write the same corrupt data on all the redundant 
disks. Suitable levels of RAID will protect you against the failure of 
one hard drive.

RAID is also not a full replacement for backup because it does not 
protect you against catastrophic failure of the computer (the system 
catching on fire and so forth). And offsite backup has the further 
advantage of protecting you against location failure (the building 
housing the computer burns down, floods, gets ground up in an 
earthquake, etc).