Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: Compactflash cards dying? | From | "Martin K. Petersen" <> | Date | 03 Feb 2003 09:08:49 -0500 |
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>>>>> "Bryan" == Bryan Andersen <bryan@bogonomicon.net> writes:
Bryan> Use a file system that is designed for use on FLASH devices. Bryan> In general FLASH devices are not very useable for systems that Bryan> need to modify data on the disk often.
Just a heads up that flash (as in MTD) != Compact Flash.
For all practical purposes a Compact Flash is an IDE disk (Or a an IDE controller with a disk behind it. Depends how you wire it).
Internally, the Compact Flash does all the wear averaging that a flash filesystem like jffs2 provides. Transparently to the application.
All Linux sees is a linear stream of bytes. Just like a disk. And it should be treated as such.
Bryan> You may wish to look at the virtual memory file system Bryan> available in the kernel if you have enough RAM. You would Bryan> mount your CompactFlash device read only and have all updates Bryan> go to the virtual memory filesystem. When you want to commit Bryan> the changes, remount the CompactFlash read/write and save the Bryan> changes then remount it read only.
tmpfs to the rescue!
Bryan> You would be surprised how fast a million writes can happen on Bryan> a disk.
Yup.
You would also be surprised how long it takes to actually *perform* a million writes on a slow piece of media like Compact Flash ;)
-- Martin K. Petersen Wild Open Source, Inc. mkp@wildopensource.com http://www.wildopensource.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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