How do you wipe a UBI filesystem?

I've figured out two other ways to do it:

ubiupdatevol -t /dev/ubiX_Y mount -t ubifs /dev/ubiX:volname /mnt/point

That works, but apparently that erases every block in the volume. That's a lot of unecessary wear. Surely you can "empty" the filesystem without erasing every block in the volume (when probably

Another option:

ubirmvol /dev/ubiX -N volname umimkvol /dev/ubiX -N volname -m mount -t ubifs /dev/ubiX:volname /mnt/point

That too seems to work, but modifying the devices volume table/list seems a bit risky compared to simply re-initializing the filesystem inside an existing volume.

Try a search:

"ubi file system utilities Linux"

Which may help, third entry down ?.

Chris

The answer is 'ubiupdatevol -t' (bracketed by umount/mount commands).

I had figured out that command worked, but one tutorial/blog I found stated that it erased every block in the volume. The way it was described it sounded like doing a 'ubiupdatevol -t' on a 20MB volume would erase 20MB of flash -- even if that volume contained a filesystem with only a few small files in it.

So I was reluctant to use it because of the uneccessary wear on the flash when used on volumes that were mostly empty. It turns out that blog was wrong/misleading.

The truncate operation doesn't erase any blocks. It _unmaps_ any _programmed_ blocks that are currently in use in the volume. Those blocks will later be erased and put back in the "free" pool during garbage collection. No blocks are erased either unnecessarily or by the command itself.