On 03/04/2014 05:16 AM, rybnik wrote:
> Sorry if this is the incorrect forum category, but I don’t know where
> else it might go.
> I don’t encrypt entire partitions, but I do encrypt certain important
> individual files, so that I have several .gpg files here and there.
> When decrypting these .gpg files, I would prefer to not decrypt them to
> my hard drive. Rather, I want to only store the decrypted files in RAM.
> Accordingly, I’m looking for a directory that only stores in RAM.
Out of curiosity, why not just use full disk encryption? Super easy to
setup, and it makes all of this much easier. Just a thought…
> What I’ve come up with so far is:
> /dev/shm and /run/tmpfiles.d
/dev/shm is what I use, yes.
> However, I can’t really be sure that those directories are really RAM,
> as, for one thing, their size is recorded to be 4 gigs, whereas I have 8
> gigs of RAM. Also, I tried putting a large file in those directories (a
> disc image), but after doing that, I checked a RAM meter and it did not
> show the appropriate increase in usage. So those two things make me
> think that those directories are NOT RAM. On the other hand, what does
> suggest that those directories are RAM is that storing files in them
> does not survive a reboot.
> So… are those directories actually RAM? If not, how can I write to
RAM? Usually. Always? I’m not sure on that. The fact that the size is
less than your total RAM is a good indicator that it’s actually RAM and
not just generally virtual memory; however, I believe /dev/shm and
anything else from ‘tmpfs’ should actually be considered “virtual memory”,
meaning it is RAM whenever possible but could also be sent to swap (files
or partition) which may or may not be encrypted on your system (see my
note about full disk encryption again). If you have no swap (like my
laptop here) then there is no reason to think that any swapping will
happen to disk and you’re safe; if you do have swap, encrypt it, or be
sure to make sure you do not put enough in /dev/shm to use it, or be sure
to somehow clean it up before you lose control of your disks.
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