Re: [opensuse-factory] /sbin/fstrim: /home: FITRIM ioctl failed: Operation not supported

["Cristian Rodríguez" <crrodriguez@opensuse.org>]

El 23/02/11 07:28, Lukas Czerner escribió:
> On Tue, 22 Feb 2011, Greg Freemyer wrote:
> 
>> On Tue, Feb 22, 2011 at 6:09 PM, Cristian Rodríguez
>> <crrodriguez@opensuse.org> wrote:
>>>  Hi:
>>>
>>>  I get the error message in $Subject if I try to use /sbin/fstrim on all
>>>  my filesystems BUT /boot which is the only one which is not encrypted.
>>>
>>>  How am I supposed to "trim" dm-crypt/LUKS volumes on an SSD device ?
>>>
>>> Thanks.

Lukas, thanks for your answer.

> No NO NO! Big no to trimming encrypted filesystems! When you are
> discarding blocks, the subsequent read from those blocks are usually "well
> defined" and hence you are giving away useful information for attacker
> trying to decrypt your filesystem. 

I understand that there might be security issues, but so far, for this
scenario the only kind of attacker from which I need to protect my
desktop is from low-funded regular thieves that may break into my home
office, unlikely that will get pass the volume password prompt ;-)


> Now, there might be some way around this to allow trimming encrypted
> volumes without serious security issue, but this is rather question for
> dm-crypt guys.

Maybe making work the "discard" mount option ?
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