Julius Adorf <jeadorf@googlemail.com> writes:
Hello,
Recently, I tried to automatically unlock an encrypted external USB hard drive on Arch Linux. I have done this by inserting an appropriate entry into /etc/crypttab. I chose the device to be unlocked by cryptsetup with a key file by UUID.
Unfortunately, the unlocking failed at boot time ("device does not exist or access denied"). After some debugging via /etc/rc.sysinit, I found out that it is a timing issue and the USB drive which is a couple of years old was not ready yet at the time the /etc/crypttab was read and processed. A similar issue has been reported here: https://bbs.archlinux.org/viewtopic.php?id=137467
For now, I have inserted a workaround into /etc/rc.local which unlocks the disk after an initial delay. This is still programming by coincidence; I wonder whether there is any better (i.e. reliable) solution to this problem?
I think systemd auto mount facility may be able to handle it. But you're probably won't want to use systemd only for this. -- Carl Lei (XeCycle) Department of Physics, Shanghai Jiao Tong University OpenPGP public key: 7795E591 Fingerprint: 1FB6 7F1F D45D F681 C845 27F7 8D71 8EC4 7795 E591