Brian K. White wrote:
How many write-read cycles does the best tape in the world accomplish before it fails? How many write-read cycles does even an ordinary hard drive accomplish before it fails?
That is what I mean. It is simply one metric among many.
Sure - we could also compare the physical size of the two, but it would be an equally inappropriate metric, IMHO.
The fact that a tape may be better by some other metric doesn't change this one.
True.
You are presenting an entirely different, also valid metric. A very good tape probably has a greater chance of reading without any errors after sitting around for 20 years than a hard drive. Greater but still nowhere near great. Even 99% chance is not great at all compared to what a hard drive does every second.
And really, who knows, maybe that tape and the hard drive have exactly the same chance after sitting around 20 years.
_I_ know. The tape wins hands down. There are many industries where documents and data must be kept for 10/20/25 years, sometimes even longer. The latter are usually microfilmed (or todays equivalent), the former are stored on tape.
Any hard drives that are currently 20 years old are nothing like the ones today,
It doesn't matter, but they're actually surprisingly similar. Spinning platters of metal with a magnetic coating.
and why should a hard drive degrade any more in 20 years sitting unpowered on a climate controlled shelf than a tape and tape drive?
Because the harddrive is full of electronics which has been designed for a very specific MTBF. For instance, it will have SMD electrolytic capacitors that, depending on the materials used, _will_ break whether they're powered on or not. Harddrives were never designed to last 25 years, whereas tapes were.
What? I shouldn't count the drive? In 20 years they will be manufacturing and selling new LTO or any other drives that can read any of the current types of tapes?
Even backwards compatibility has not gone that far so far so I don't know how you can bank on that happening more in the future.
Where is the current tape drive made today that can read any tape that was made 20 years ago?
http://www.sun.com/storage/tape_storage/tape_drives/9840/ (not _any_ tape, but those with which the drive is comptabile of course). /Per -- Per Jessen, Zürich (16.3°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org