l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
December 2: Social gathering
Next Installfest:
TBD
Latest News:
Nov. 18: Club officer elections
Page last updated:
2003 Dec 03 09:27

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] DVD playback and burning under Debian; IDE DVD+/-RW drive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] DVD playback and burning under Debian; IDE DVD+/-RW drive



On Wed, Dec 03, 2003 at 04:52:29AM -0800, Mark K. Kim wrote:
> I feel pretty comfortable using flash like a hard drive with some
> precautionary measures (with or without jffs).  The number of times you
> can write on flash compared to DVD-RW are a couple orders of magnitude of

Er actually for the 2 types of NAND compact flash that have 10 and 100
times the number of write cycles.

JFF2 can have on the order of 100-1000 times less writes, I forgot
to mention a 3rd difference.  I believe compact flash you can set a zero
to a 1 for "free" but have to clear entire blocks.  So JFFS2 can take
advantage of this to additional reduce the number of writes.

> difference, and comparing them makes it seem like they're on a similar
> level, but they're not (not that you were implying that.)  Just a footnote
> here...  ignore me.

A good point, if you have the 10k write cycle type playing with a large
directory, deleting it, and repopulating it can cause significant wear,
I'm not familiar enough with it to be sure, but I think deleting 4000
files would like cause something on the order of 4000 writes to the
inode for the directory which would be on a couple of blocks.  Although
metadata is stored async so maybe it would be dramatically less then
that.

In any case, with compact flash or CDRW I'd rather use every block of
the filesystem 1,000 (CDRW), 10,000 (SLC NAND), or 100,000 (MLC NAND)
times then just have the worst case being the superblock.

As it turns out there are some issues with JFFS2, currently it's limited
to 4GB, and it's not clear that the datastructures involved would scale
well to filesystems that big.

-- 
Bill Broadley
Mathematics
UC Davis
_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech



LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Appahost Applications
For a significant contribution towards our projector, and a generous donation to allow us to continue meeting at the Davis Library.