Lee Marzke on 15 Jul 2010 14:04:20 -0700 |
On 07/14/2010 10:07 PM, Richard Freeman wrote: On 07/14/2010 08:59 PM, Lee Marzke wrote:Well for Ubuntu 10.04, you just boot from the CD rescue partition, and then open the encrypted LVM, and fsck the disk. You may have to manuallysearch for the proper lvm device names ( lvscan, lvmdiskscan, vgscan, etc )How robust is LVM with encryption? Is the amount of data lost during a power failure comparable to not using encryption? I imagine that it must encrypt each block separately, so that if there is some kind of interruption you only lose one block of disk. I've used ext3 ( now ext4 ) on encrypted LVM (Ubuntu) for almost 4 years now on my laptop with no issues. Ocassionally a hang due to sleep/hibernate failures typically get fsck'ed automatically ( for /home ) and only one time did I have to boot the install CD to manually fsck / ) That would be my main concern with it - if you can simply manually create the devices and fsck everything that isn't too big a deal. I just don't want one byte lost to result in half the drive getting scrambled. I imagine that the concern with scrambling the disk is possible only during writes of disk meta-data, and with ext3 / ext4 that should be journaled. Otherwise only the file being written at the time would be subject to corruption.That seems to be my experience as well, I don't recall any issues after forcing a fsck. Using a COW filesystem with built-in encryption would probably be a good move as well. You essentially get data=writeback on such a filesystem for free, which would probably help mitigate problems caused by errors at lower layers.Rich Lee -- "Between subtle shading and the absence of light lies the nuance of iqlusion..." - Kryptos Lee Marzke, lee@marzke.net http://marzke.net/lee/ IT Consultant, VMware, VCenter, SAN storage, infrastructure, SW CM +1 484-961-0369 voice +1 484-348-2230 fax begin:vcard fn:Lee Marzke n:Marzke;Lee org:4AERO adr;dom:;;;Collegeville;PA;19426 email;internet:lee@marzke.net title:Consultant tel;work:800 393 5217 tel;fax:484 348-2230 tel;cell:484 961-0369 url:http://4aero.com version:2.1 end:vcard ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
|
|