Am 02.04.2007 um 19:51 schrieb Adam Tauno Williams:
We currently use LTO. It works ok - for a tape. As all tapes it is slow as hell for recovery case, a LTO media is mechanically robust but can't be used that often (we change media after 15 backup cycles and already had rejected tapes).
We have three LTO drives; life cycle of a tape is MUCH MUCH longer than that.
Can be - we also have tapes which last longer, but after 3 tapes in a short period which were rejected because of write errors after less then 20 write cycles we decided to not take the risk and were going down to 15 cycles generally. We also have more then one LTO drive in use (here in our company and for different customers) and - yes - some years ago a tape was a good idea. But especially to backup current amounts of data tape is completely outnumbered.
Next time we need to change backup system we will go to USB/eSATA disks - one disk for each tape media we currently have in use: Pro:
- you don't need an expensive tape-drive
- you can already have 1TB per media
You can get 1TB drives?
Ok - give it 3 month ... : HITACHI HDS721010KLA330 - Auftragsbezogene Bestellung - vorauss. ab 11.07.2007 lieferbar - http://www.emedia-shop.de/
- you can reuse such a disk much more often then 15 times
Not likely if you are trundling them back and forth between an offsite backup location. The durability of a caddied drive isn't event remotely close to that of a magnetic tape. Not even close.
I'm in project business: I have to do "show programming" at customers - to have a local copy of what I did on the remote system (these systems are not always accessible for remote administration) I'm used to have a copy of such systems on a 100GB 2.5" USB disk. This disk always is carried in my laptop bag, it has to deal with mechanical, electrical and whatever conditions - I just don't care about this disk - after much more then a year it still is happily alive. Every laptop has a disk - if disks would be that easy to break no company would dare to produce disks and give a 2 or more year warranty.
- a disk _may_ not be usable as long as a tape media
It won't be.
A disk may not be a good idea as a 10 year archive media - I don't know. But for daily backup it lasts long enough. If you have this one media per week day, one media per week, one media per month scheme you are quite save that you have a recent backup.
[...] but for a server with up to a terrabyte online storage it is a robust, easy to handle, relatively cheap and
Not robust. Not easy to handle (*FRAGILE*) and certainly NOT electromagnetically robust; one good jolt of static electricity and your backup is fried. Magnetic tape is amazingly resilient.
Maybe you work in a high voltage environment, maybe in thunderstorm research ... but for what I know the extra bucks for tape infrastructure can be invested in something more useful. I have been with you less then 2 years ago: backup - that means tape or WORM or something other designed to be used as backup. Times change.I had to change my mind. BTW: if you are really in a hurry and you did full system backups you can even activate one of this backup disks directly - in this case you can be back online less then half an hour after you started "recovery" - even without having completely redundant hardware. There are customers who would give a leg for such a message after the server gave smoke signals ... Ralf -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org