[ale] 26G to backup

[JD]

On 12/31/2011 12:02 PM, Jim Kinney wrote:
> Tape. I can still play VHS movies I bought/made 20+ years ago. My VXA drive(s)
> are 10+ years old and the data on those tapes is still perfectly recoverable.
> 
> Research what NASA is doing to address this issue as they have nearline data
> going back to the early 60's. Last I heard, some of the data was being lost as
> the drive components were failing faster than they could extract it from the
> tape the data was stored on.
> 
> Juggled every year is paranoia and more work than it's worth unless the storage
> medium is DVD. With hard drives past the infant mortality burn-in time, the data
> loss is determined by usage. More usage = more wear on the platter. I've seen
> some stuff around arguing that the data "evaporates" on a powered down drive
> faster than on a power on drive. I call shenanigans on that. Magnetic domain
> dispersal is a known problem than is addressed with a disk refresh process (i.e
> dd if=old_drive of=new_drive; dd if=new_drive of=old_drive). The wear aspect of
> a spinning drive is the bearings. Once those fail, the data is mostly lost
> without EXPENSIVE tech work. The drive sitting on a shelf in a static safe
> container with a moisture adsorbent pack will survive longer than one running in
> a system.

I actually worked for ICS at JSC during a data migration effort in the mid-1990s
and helped migrate programs, code and data from quarter inch to DAT.  I was not
on the project full-time, but my team chipped in with crunch time work across
many projects. We were simply migrating the data off older technologies to newer
ones. This worked fine provided only the data was necessary. More and more, the
data was in proprietary formats and the exact version of the code was needed to
make any sense out of the data. How long do you retain a specialized computer
that did 1 job for 20 yrs?  Some of these computers were one-of-a-kind.

I've been using DVD for long term media storage for about a decade.  A few years
into this effort, I started adding 10% par2 data to the media to aid with
restoration later. I've lost some data from those really early volumes, but none
with any of the later volumes with par2 files.  DVD is not my preferred archive
method. It is too much work.  HDDs are.  They are cheap, fast, and easy to
migrate.  Having 2 copies of the data is trivial.  IDE interfaces still work.
When we all migrate from SATA, there will probably be 10 yrs before we need to
worry about migrating the data on SATA.  Only media goes to DVD, all other data
is backed up to HDDs.

Tape sounds great until you look at the expense.  Even if you have 10TB of data
at home, you'll probably come out cheaper with HDDs.  HDDs are definitely more
convenient too.  Sure, you can get a refurb, out-of-support tape drive for $200,
but do you really want to trust your critical data to that device?  New LTO-4
drives are around $4K, you'll need SCSI adapters and costly tape media.  $4k is
a bunch of 2TB HDDs, even with prices today.  Only in a corporate situation does
tape make sense.