[nycbug-talk] off site backup

Jerry B. Altzman jbaltz
Sun Oct 30 14:57:59 EST 2005

On 10/30/2005 2:46 PM, alex at pilosoft.com wrote:
>>Given the engineering of drives, they *do* tend to like running all the
>>time, or being off, but the torque to spin up from zero can be damaging.  
>>(So can dropping it.)
> rotating/seeking will eventually kill your motor/bearings.

...after 200 kilohours, on average...

>>Multi-tape-drive jukeboxes mitigate this nicely.
> It is however quite unusual to have raid tapes. (i.e. you would need 3 
> tape drives, and 2 out of 3 tapes to do restore). I've never heard of 
> anyone doing that.

In fact, we *did* do tape duplexing -- writing data to two drives 
simultaneously. (This would be something like RAIT 1, I suppose.)

>>>Keep in mind that media for tape (say, ~40$ for LTO 200G) is about 1/4
>>>of cost of similar hard drive media.
>>with transfer rates correspondingly lower :-)
> Eh, I think it's close enough. LTO has 70MB/sec transfer rate. 7200 
> RPM drives have ~60MB/s, 10k rpm ~80MB/s

15k rpm SCSI?

>>With recordable DVD media being relatively cheap, is anyone archiving to
> The DVD jukeboxes began to appear fairly recently (as in 1-2 years ago). 
> Unfortunately, the density is still not there - as in, 100-DVD changer is 
> "only" 470GB. This might change with dualside duallayer DVDs...

Once again, true -- but if your tablespaces can fit nicely in 4.7GB, it 
might become cost effective.

> -alex

jerry b. altzman  jbaltz at 3phasecomputing.com  +1 718 763 7405

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