Date: Sun, 4 Mar 2012 19:32:36 -0500 From: Robert Simmons <rsimmons0@gmail.com> To: freebsd-hackers@freebsd.org Subject: Where and when /etc/fstab is checking during boot Message-ID: <CA%2BQLa9B8y7_2wB-7gUZft95O%2BWMYYEArLBRn0DG6fAUFJ%2BszMg@mail.gmail.com>
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I've just finished working though building a FreeBSD box with an encrypted root partition as mentioned in the geli(8) man page: "Ask for the passphrase on boot, before the root partition is mounted. This makes it possible to use an encrypted root partition. One will still need bootable unencrypted storage with a /boot/ directory, which can be a CD-ROM disc or USB pen-drive, that can be removed after boot." I've noticed something quite interesting about the way that fstab is read during boot. If you follow the instructions exactly as they are written in the geli(8) man page you soon discover that you also must have an /etc/fstab file in that same unencrypted partition. But this need not be the complete fstab file. It only needs to have the one line that describes /. Later, after the encrypted partition is mounted, the /etc/fstab inside the encrypted partition is then read and all other partitions listed in fstab are mounted as written there. I've tested this by putting empty fstabs and fstabs with just the line for / in both locations and booting to see what happens. Is this the correct behavior? Shouldn't the fstab file be read completely once and not twice?
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