[ale] archiving backups

[Alex Carver]

On 2014-08-06 12:33, Chris Fowler wrote:
> On 08/06/2014 02:51 PM, Scott Plante wrote:
>> This is an instance where hard links are probably called for--no need
>> to create a dupes directory. Each hard link is equal, and the file
>> only goes away when the last link is deleted.
>>
>>
>> There is a command 'fdupes' that's available in the standard
>> yum/zypper repos (and probably others) that will automatically find
>> duplicate files and, with --link option, create hard or soft links
>> automatically.
>>
> 
> That looks good.  I think I would want to know what my dupes are. This
> is where symbolic links would help.  I intend to place much of this on a
> drive and then to cloud storage.  I'm not sure how they handle hard links.
> 
> This job is starting to suck.
> 
> I started going through my old drives and it appears that many of them
> have been wiped.  Another symptom of age.  I've been down the road of
> cleaning my drives.  I just did not throw them out.
> 
> One thing I did find was a pack of CVS backups.  I would have done this
> before a software release.  Since these are snapshots of a system still
> in place then I think the best idea is to destroy them and have one
> master CVS backup.   CVS never changed in a reverse fashion.  Same as my
> SVN.
> 
> For photos I think I'll get the creation date and store them in
> directories sorted by year/month.  Those would go on the master backup
> and I think also I would put them on 2 32GB USB sticks.  One for
> redundancy.  A question for you guys would be USB stick or SDHC?   With
> the stick I have to worry about more failure than SDHC?  Logical eh? 
> Speed is a non-issue for archive.

Neither.  The nominal retention time for NAND flash is 5 years or less,
depending on the number of cycles of reads and writes to the cells.  The
charge stored in the gate oxide bleeds away after some time leading to
the memory cell losing that bit of information.  This is especially
important for the larger capacity flash devices which use MLCs to
achieve the larger capacity.  That retention time is also factoring in
the abilities of the on-board ECC to correct for lost bits.  For long
term storage go with properly stored magnetic media.