On Tue, Mar 13, 2012 at 12:49 PM, Florian Philipp <li...@binarywings.net> wrote: > Am 13.03.2012 17:26, schrieb Michael Mol: >> On Tue, Mar 13, 2012 at 12:11 PM, Florian Philipp <li...@binarywings.net> >> wrote: >>> Am 13.03.2012 12:55, schrieb Valmor de Almeida: >>>> On 03/11/2012 02:29 PM, Florian Philipp wrote: >>>>> Am 11.03.2012 16:38, schrieb Valmor de Almeida: >>>>>> >>>>>> Hello, >>>>>> >>>>>> I have not looked at encryption before and find myself in a situation >>>>>> that I have to encrypt my hard drive. I keep /, /boot, and swap outside >>>>>> LVM, everything else is under LVM. I think all I need to do is to >>>>>> encrypt /home which is under LVM. I use reiserfs. >>>>>> >>>>>> I would appreciate suggestion and pointers on what it is practical and >>>>>> simple in order to accomplish this task with a minimum of downtime. >>>>>> >>>>>> Thanks, >>>>>> >>>>>> -- >>>>>> Valmor >>>>>> >>>>> >>>>> >>>>> Is it acceptable for you to have a commandline prompt for the password >>>>> when booting? In that case you can use LUKS with the /etc/init.d/dmcrypt >>>> >>>> I think so. >>>> >>>>> init script. /etc/conf.d/dmcrypt should contain some examples. As you >>>>> want to encrypt an LVM volume, the lvm init script needs to be started >>>>> before this. As I see it, there is no strict dependency between those >>>>> two scripts. You can add this by adding this line to /etc/rc.conf: >>>>> rc_dmcrypt_after="lvm" >>>>> >>>>> For creating a LUKS-encrypted volume, look at >>>>> http://en.gentoo-wiki.com/wiki/DM-Crypt >>>> >>>> Currently looking at this. >>>> >>>>> >>>>> You won't need most of what is written there; just section 9, >>>>> "Administering LUKS" and the kernel config in section 2, "Assumptions". >>>>> >>>>> Concerning downtime, I'm not aware of any solution that avoids copying >>>>> the data over to the new volume. If downtime is absolutely critical, ask >>>>> and we can work something out that minimizes the time. >>>>> >>>>> Regards, >>>>> Florian Philipp >>>>> >>>> >>>> Since I am planning to encrypt only home/ under LVM control, what kind >>>> of overhead should I expect? >>>> >>>> Thanks, >>>> >>> >>> What do you mean with overhead? CPU utilization? In that case the >>> overhead is minimal, especially when you run a 64-bit kernel with the >>> optimized AES kernel module. >> >> Rough guess: Latency. With encryption, you can't DMA disk data >> directly into a process's address space, because you need the decrypt >> hop. >> > > Good call. Wouldn't have thought of that. > >> Try running bonnie++ on encrypted vs non-encrypted volumes. (Or not; I >> doubt you have the time and materials to do a good, meaningful set of >> time trials) >> > > Yeah, that sounds like something for which you need a very dull winter > day. Besides, I've already lost a poorly cooled HDD on a benchmark.
Sounds like something we can do at my LUG at one of our weekly socials. The part I don't know is how to set this kind of thing up and how to tune it; I don't want it to be like Microsoft's comparison of SQL Server against MySQL from a decade or so ago, where they didn't tune MySQL for their bench workload. -- :wq
