[svn.haxx.se] · SVN Dev · SVN Users · SVN Org · TSVN Dev · TSVN Users · Subclipse Dev · Subclipse Users · this month's index

OT: SV: Re: SVNCopy - The coolest tool for moving and syncing WCs!

From: Hans-Emil Skogh <Hans-Emil.Skogh_at_tritech.se>
Date: 2006-07-24 10:11:54 CEST

>> http://en.wikipedia.org/wiki/USB_flash_drive
> Thanks for the link. However, nothing in the article
> says what constitutes an "erase/write cycle".

Ehrm. Is it not clear enough? To erase and then write a block of memory.
I do not see the need of a detailed definition here.

> Most OSes actually intervene for USB mass storage devices
> and don't actually write any data to the drive until
> sufficient data has been acquired in RAM for a write
> operation so as to lengthen their lifetime and to shorten
> write operation times from applications.

This goes for floppies, hard-drives and other media too and has not
necessarily anything to do with flash-specific wear levelling.

> So, if the power goes out or you pull the USB drive
> instead of properly ejecting, poof!

This goes for any other media as well...

> Flash RAM has historically only been capable of a few
> thousand write operations before failure (writing, from
> my perspective, means filling and emptying every bit available).

You have to separate technologies here. NOR-based flash have an
approximate lifetime of 10,000 to 1,000,000 erase cycles. NAND (that is
mostly in use today) has about 10,000,000. I think you will be safe for
quite some time....

> The truth is: No one has really bothered to test the true
> lifespan of flash RAM in USB thumbdrives to get a real number.

Haha. :-D
Do you honestly think that the researchers inventing this technology
haven't tested it?
Do you really think that the companies making a living of selling these
devices has done so as well?

> Flash drives are "cool" but I don't trust them for anything
> but moving common data let alone critical data.

If that was justified I think the companies selling thumb-drives as
daily backup-technology for "mobile professionals" would be in quite
some trouble... (Check www.sandisk.com for example.)

I'm not saying it's an alternative to rsync and similar technologies,
but I think you could up your fate in flash-ram technology. It works.
(Just don't put your windows swap-file on it! ;-) )

Hans-Emil

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@tortoisesvn.tigris.org
For additional commands, e-mail: dev-help@tortoisesvn.tigris.org
Received on Mon Jul 24 10:11:49 2006

This is an archived mail posted to the TortoiseSVN Dev mailing list.