CF cards as storage - wear leveling
elson at pico-systems.com
Sun Mar 19 13:08:15 CDT 2017
On 03/19/2017 11:06 AM, Jules Richardson via cctalk wrote:
> I just bought an IDE-CF adapter the other day with the
> intention of replacing the spinning rust in my disk
> imaging system (which is some early/mid-90s 80486-based
> However, the CF entry on Wikipedia says:
> "Most CompactFlash flash-memory devices limit wear on
> blocks by varying the physical location to which a block
> is written. When using CompactFlash in ATA mode to take
> the place of the hard disk drive, wear leveling becomes
> critical because low-numbered blocks contain tables whose
> contents change frequently. Current CompactFlash cards
> spread the wear-leveling across the entire drive. The more
> advanced CompactFlash cards will move data that rarely
> changes to ensure all blocks wear evenly."
> ... I'm a little wary about the way it says "most CF
> cards", implying that there are some out there which don't
> do any wear-leveling at all. So, the obvious question: is
> there a way of knowing which cards are going to be good
> and which are useless as IDE replacements? Maybe by age,
> capacity, manufacturer? I'd prefer not to invest time into
> setting software up only to find that the card fails in a
> matter of weeks.
I have several systems that have the old Beagle Board
computer in them. They are not run continuously, but have
been run for months at a time. These use regular-size SD
cards as the "disk" for a Linux OS. I did set the noatime
flag on the file system. They are still running on the
original SD cards.
I have a Beagle Bone running LinuxCNC under a Debian-based
distro, and I fire it up at various times to text boards I
make, and it is still running the original micro-SD card.
I don't think anybody is actually using real CF cards
anymore, they are about a decade out of date.
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