USB vs DVD, was: Fedora Present and Future

[Chris Murphy]

On Mar 23, 2014, at 2:36 AM, Ralf Corsepius <rc040203 at freenet.de> wrote:

> On 03/23/2014 08:56 AM, Frank Murphy wrote:
>> On Sat, 22 Mar 2014 18:29:02 +0000
>> Timothy Murphy <gayleard at eircom.net> wrote:
>> 
>>> Ed Greshko wrote:
>>> 
>>>> Does anybody nowadays actually burn CDs or DVDs?
> 
> Yes, because unlike USB-sticks, I am archiving them and resort to using them as "ready-to-use/off-the-bookshelf" media, e.g. in cases of "emergencies".

Offtopic but for what it's worth pretty much all dye based DVD is effectively disqualified from archiving because of the massive variance in errors, with the initial error rates (immediately after writing) busting the relevant standard (ISO/IEC29121). To even consider it requires ISO/IEC 10995 discs, a dedicated archival recorder, periodic testing strategy to know when to migrate data to new discs, and proper storage conditions (low temperature and humidity).

Stamped DVD (packaged movies and games) is a whole different animal, they're reliable short of microwaving them, but are impractical for backups.


On Mar 23, 2014, at 5:12 AM, Tim <ignored_mailbox at yahoo.com.au> wrote:

> Just recently I had to boot from USB to install onto a laptop with no
> optical drive.  I found four different methods of putting a Linux
> installer onto a USB.  One of them involved Windows, so that was out.
> Two of them were Linux programs for writing installers to the flash
> drive.  One required adding things to a current install that I didn't
> want to do.  The other was less painful, and worked for writing one
> installer to a USB, but not for another (I tried Fedora and Ubuntu on
> this laptop).  The last was plain dd if=/install.iso of=/def/flashdrive
> (I'm paraphrasing), and that worked for the one that didn't work the
> other way.
> 
> All of which was more hassle than burning a disc, and was actually
> slower than burning a disc for one of the methods (I don't recall which,
> but I tend to think it was the dd method).

The slowness of USB writing is probably the block size. I have a Kingston USB that writes at 20MB/s if the block size is 256KB or larger. At the default of 512 byte block sizes, it's abysmal, not even 1MB/s. Maybe 250KB/sec? A Lexar USB stick writes at 1MB/s with 512 byte block sizes, and maxes out at 4MB/s. Point being the media makes a big difference, but they all write slowest with 512 byte block sizes so I'd think there's possibly some room for optimization here.


Chris Murphy