On 26 Sep 2008, at 19:21, James wrote:
Neil Bothwick <neil <at> digimed.co.uk> writes:
Bear in mind the limited write lifetime of flash memory. Don't put /
var
or /tmp on such a card if you can avoid it.
Well, I'm not sure any other alternatives are attractive? Unless
I find a way to mount those partitions off of a usb stick, or
some other idea?
Since they are not frequently updated and have minimal installed
software
(iptables on firewalls and DNS on DNS servers) accompanied by the
fact that most devices have internal wear leveling; it should take
many years to reach the write cycle limits?
I've read a fair little bit about this subject and never gotten a
definitive answer on what is "safe", but AIUI the wear-levelling on
flash memory is filesystem-dependent. Thus it may work fabulously well
for FAT filesystems, and not at all for EXT.
Having said that, from my experience most of the nay-sayers telling
you not to put stuff on a CFcard for this reason are talking
speculatively - I have encountered one or two people who have used
CFcards very happily for years. It does seem sensible to store logs,
tmp & Portage directories on a RAM disk or hard-drive, NFS mounted if
necessary, but generally I would say just get on & try it. 4gig
CFcards are, after all, cheap as chips these days. Oh! It may be
possible to reduce the number of writes to the card by changing mount
options in /etc/fstab and have writes flushed less frequently.
You might consider posting about this - or merely searching the
archives - on the MythTV users list, as the subject does come up
periodically and there are a number of people using CF cards in this
way to reduce noise in the TV room.
You could dd the card to a file and use the same file every time
you need
a new card.
Um I do not mean to be a pain, but could you provide a little bit
of pseudo-syntax? Assume I have shutdown a 4 GB CF firewall card
and moved it to a reader/writer on another machine. First I need
to format the raw (new) 4GB CF card from a reader.
Put CFcard with existing filesystem in card-reader:
dd if=/dev/sdX of=~/diskimage.img
Swap cards in reader, writing to blank now:
dd if=~/diskimage.img of=/dev/sdX
You need to ensure that neither card is mounted when following this
procedure - booting from a LiveCD or 3rd filesystem.
Stroller.
