[Libguestfs] FYI: cryptsetup luksOpen now requires loads of RAM

[Richard W.M. Jones]

https://gitlab.com/cryptsetup/cryptsetup/issues/488

This prevents virt-* tools from opening encrypted partitions
automatically.

Even 1024M isn't sufficient.  I had to bump the memory up to 1400M to
make it work, which is just too big for routine use.  Even worse if
the RAM size isn't quite large enough (eg 1200M) cryptsetup crashes.

I'm not sure what to do about this now.  The worst aspect is probably
the lack of any error message from cryptsetup when it fails, but this
is at least the easiest to fix because we can catch the exit code and
turn that into an error message.

Rich.

-- 
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