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