[Luks dm-crypt] device mapper cannot find root at boot.

vinhsynd · 2010-09-25 06:05:07

I'm using the current netinstall cd which seems to have support for creating dm-crypt partitions from within the installer.

I used cfdisk to create 3 partitions:

100mb boot
4096mb swap
100000mb for root

Then I manually configured the block devices using the UUID option

sda1 raw_fs -> Boot with ext2
sda2 raw_fs -> Swap
sda3 raw_fs -> dm-crypt named root
device_mapper/root -> / with JFS

I entered my passwords and it continued through the rest of the installation without issue.

I made sure the my mkinitcpio hooks were present: udev autodetect pata sata scsi usb usbinput keymap encrypt filesystem

Then once I booted, I waited 10 seconds for "sda3 to settle" then waited another 10 seconds for "device_mapper/root to settle" and then I guess gave up and pushed me to the ramfs shell.

What did I do wrong and how can I not do that again?

siriusb · 2010-09-25 07:15:28

Try using sdaX names. When your system is up, check UUIDs with

 fsarchiver probe simple

. I don't know why but blkid didn't show the correct UUID for one or two partitions when I switched to UUIDs.

vinhsynd · 2010-09-28 00:56:41

Good advice.

I tried it with sdX names and it works for the most part.
There are instances where it will boot and fizzle but most times it seems to notice the drive without fuss.

Thankyou.

How did you fix your issue with UUIDs?
I'd prefer to use them as it seems thats a better way to go for device identification.

siriusb · 2010-09-30 14:50:19

I use uuid, too. You just need the correct data. That's why I suggested to run fsarchiver probe simple command, I'm sure it will give you the correct uuid. Unfortunately I have no idea where did blkid get that false(?) uuid in my case from.
And make sure that you use the correct syntax: /dev/disk/by-uuid/.....

Arch Linux

#1 2010-09-25 06:05:07

[Luks dm-crypt] device mapper cannot find root at boot.

#2 2010-09-25 07:15:28

Re: [Luks dm-crypt] device mapper cannot find root at boot.

#3 2010-09-28 00:56:41

Re: [Luks dm-crypt] device mapper cannot find root at boot.

#4 2010-09-30 14:50:19

Re: [Luks dm-crypt] device mapper cannot find root at boot.

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