Am 06.12.2011 17:22, schrieb Kevin Chadwick:
On Tue, 06 Dec 2011 17:08:46 +0100 Thomas Bächler wrote:
Generally, running 'rm' on a file means it's gone. It's the specification of 'rm'.
Sort of, more so on SSDs but it's just harder to reconstruct because SSDs writes are spread out as sectors get worn out much quicker. For speed, /bin/rm just removes the reference
I'm not talking about implementation, but about specification. There is no guarantee that the file is gone, and there is also no guarantee that it can be recovered. If you run 'rm', you should expect the file to be gone for good - because that is what can happen according to the specification. Re: SSDs: File systems like ext4 can run discard commands that will tell the SSD firmware that the data is no longer needed - so even though the data is still there, the place on the SSD where the data resides is no longer associated with the logical "block" where they were. If you read that block, the SSD firmware may simply return a bunch of zeroes. Recovering data in this case requires raw access to the flash memory itself (which modern SSDs won't grant you).