If you make it read-only you don't need logs. During your period upgrades,
get a SHA sum of the whole partition. Make sure that matches the standard.

On Wed, Nov 18, 2009 at 15:01, Ted Stern <[email protected]> wrote:
> On 18 Nov 2009 14:13:08 -0800, Derek Simkowiak wrote:
>>
>>    Good info... interesting stuff.
>>
>>    But one could argue that a read-only O.S. partition goes against
>> the goal of security.  Part of "security" is change management,
>> auditing of log files, and updated software.
>>
>>    With the ZFS+RAM disk model, you could wind up running un-patched
>> software everytime you reboot.  And if the system gets attacked while
>> running, any audit trail (relevant log files) would also get wiped at
>> reboot.  Intrusion detection systems and C.M. software (e.g. Tripwire)
>> would have their databases reverted at every reboot.  And there will
>> be headaches dealing with files like /etc/ssh/ssh_host_rsa_key and
>> /etc/ssl/certs/root.pem (which are supposed to be unique for each
>> computer).
>>
>>    There's something to be said for thin clients with read-only
>> firmware, but if you want a fully functional Linux system
>> (incl. software updates and network daemons) I think the O.S. has to
>> be writable.
>
> OP here.  I can't sell the idea of having automatic security updates
> from outside the secure firewall, so change management needs a
> different paradigm.
>
> I envision OS updates being done offline: once every couple of days
> you plug your USB key into a secure workstation and write an updated
> OS onto it.  That could be coordinated with virus-checking and backing
> up /home.
>
> So maybe there's a way to make the OS without it being read-only: you
> could use that same docking time to scan the OS partition to check
> logs and see whether any exploits have been attempted.
>
> Ted
>
>>
>> --Derek
>>
>> On 11/18/2009 01:53 PM, Keziah Wesley wrote:
>>> No need to load the whole r/o partition into the ram disk though -
>>> I haven't researched the details but I'm thinking you could:
>>> - use ZFS
>>> - use ZFS's integrated LVM capabilities to include a ram disk device
>>> and your r/o partition in the same filesystem, with the ram disk as / and
>>> the r/o stuff under a /ro subdirectory
>>> - cp -R /ro/* /
>>> - because of ZFS deduplication, the ram disk will now be using almost no
>>> space because every file is really a pointer to the /ro version. When a file
>>> under / is modified, however, the pointer is replaced with the new content.
>>>
>>> Pro: a filesystem that is read-only on disk but read-write while running,
>>> as loading all the content into a ram disk would be, except the ram disk
>>> will only take as much space as the files that are actually modified (a very
>>> small portion)
>>> Con: more complicated to implement; most systems these days have enough
>>> RAM that unless you're requiring a huge USB stick for your read-only 
>>> content,
>>> you don't really need the space anyway.
>>>
>>> tl;dr: use ZFS's LVM & dedup to create a smart "sparse" ram disk.
>>>
>>> Just sayin'.
>>>
>>> -Kz
>>>
>>> On Wed, Nov 18, 2009 at 13:27, Chad R Mayfield <[email protected]> 
>>> wrote:
>>>
>>>> It has partially been done by a few people.  The one that sticks out in my
>>>> mind is, http://bcable.net/system.php.  Of course this is using a 
>>>> customized
>>>> GRML live cd and loaded into a ramdrive each boot, but I don't see why you
>>>> could not do something similar with a flash drive.
>>>>
>>>> ---
>>>> Chad R Mayfield
>>>> [email protected]
>>>> GPG Key: 0C9A026F
>>>> http://www.planetmayfield.com/
>>>> http://www.chadmayfield.com/
>>>> http://www.linkedin.com/in/chadmayfield
>>>>
>>>>
>>
>
> --
>  Frango ut patefaciam -- I break so that I may reveal
>

Reply via email to