Hi Andreas, Ludo's response clarified a lot of things for me. The only remaining feedback I have is that (1) to aid the reader, you should consider adding a cross-reference from "(guix) Mapped Devices" (in the part where you mention that certain modules must be added) to "(guix) Initial RAM Disk", and (2) you might want to look into using the "Auto Assembly" feature of mdadm (see below). If you've tested the changes, though, and it works, I see no reason not to commit this and enable everyone to enjoy the use of RAID arrays! :) Andreas Enge writes: > On Sat, Jul 23, 2016 at 10:43:58PM -0700, Chris Marusich wrote: >> Cool! Is it possible to use them in combination? Using the example >> From the documentation, would it possible to use LUKS to create an >> encrypted /dev/mapper/home which uses /dev/md0 instead of /dev/sda3? > > unfortunately not. This is an area where some work should be invested. > It would require to do things properly in order also. LVM support also > comes to mind. I think these devices can be staged in an arbitrarily > complex way, no? Encrypting a RAID device, or creating a RAID device > from encrypted partitions, for instance (of which the former sounds more > reasonable to me). I agree it would be a nice feature, but if your patch is working right now to enable the use of RAID, then I think it would be fine to submit your patch now and add such a feature later. >> I understand that in Linux, the device file names (e.g., /dev/sda3) can >> sometimes change unexpectedly. If they change later on, will anything >> bad happen? > > Yes, the RAID could not be assembled, and then the machine could not boot > up. But I have never experienced this kind of problem for hard disks. It occurs occasionally [1], but the fewer disks you have, the less likely you are to observe it. I wonder if you can use mdadm's "Auto Assembly" feature (see "man 8 mdadm" for details) to avoid this issue entirely? It sounds like you might not even need to specify a source device list, if the description of "Auto Assembly" is to be believed. [1] For example: https://serverfault.com/questions/140071/hard-drive-device-names-are-different-from-one-reboot-to-another-in-ubuntu -- Chris