我已经使用 Jessie 几个月了，几周前启动计算机时遇到了问题。
我在启动时遇到了这个错误：
early console in decompress_kernel
Decompressing Linux... Parsing ELF... done.
Booting the kernel.
Loading, please wait...
fsck from utils-linux 2.25.2
/dev/mapper/fabienm-root: clean, 12578/262144 files, 179719/1048576 blocks
Gave up waiting for /usr device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/mapper/fabienm-usr does not exist. Dropping to a shell!
modprobe: module ehci-orion not found in modules.dep
BusyBox v1.22.1 (Debian 1:1.22.0-9+deb8u1) built-in shell (ash)
Enter 'help' for a list of built-in commands.
/bin/sh: can't access tty; job control turned off
(initramfs)
如果我3.16-2-amd64在 Grub 中选择内核，它会“正确启动”吗？并生成此日志：
early console in decompress_kernel
Decompressing Linux... Parsing ELF... done.
Booting the kernel.
[ 0.000000] tsc: Fast TSC calibration failed
Loading, please wait...
[ 6.300000] systemd-fsck[173]: /dev/mapper/fabienm-root: clean, 12578/262144 files, 179719/1048576 blocks
[ 8.700000] [drm:cpt_set_fifo_inderrun_reporting] «ERROR» uncleared pch fifo underrun on pch transcoder A
[ 8.700000] [drm:cpt_serr_int_handler] «ERROR» PCH transcoder A FIFO underrun
[ 9.000000] systemd-fsck[432]: /dev/sdb1: clean, xxx/xxx files, xxx/xxx blocks
[ 11.200000] systemd-fsck[553]: /dev/mapper/fabienm-var: clean, xxx/xxx files, xxx/xxx blocks
[ 11.600000] systemd-fsck[560]: /dev/mapper/fabienm-home: clean, xxx/xxx files, xxx/xxx blocks
[ 11.700000] systemd-fsck[564]: /dev/mapper/fabienm-usr: clean, xxx/xxx files, xxx/xxx blocks
[ 11.900000] systemd-fsck[578]: /dev/mapper/fabienm-tmp: clean, xxx/xxx files, xxx/xxx blocks
[FAILED] Failed to start LSB: VirtualBox Linux kernel module.
see 'systemctl status virtualbox.service' for details.
[ OK ] Started LSB: Start or stop the inetd deamon..
[ OK ] Started LSB: KernelNFS server support.
...
一旦我使用这个工作内核启动，我就可以查看 /proc/cmdline：
$ cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-3.16-2-amd64 root=/dev/mapper/fabienm-root ro quiet
该内核可以与所有 Debian 软件包配合使用，但 Virtualbox 除外，因为 Virtualbox 需要3.16.0-4-amd64内核才能工作。
有人知道如何让3.16.0-4-amd64内核在 Jessie 上启动吗？
[编辑]
在 initramfr （内核 3.16.0-4-amd64）上，我启动了一些命令：
(initramfs) grep dm_mod /proc/modules
dm_mod 89373 4 - live 0xFFFFFFFFA023E000
在 /dev/mapper 中我只看到 fabienm-root 分区：
(initramfs) ls -l /dev/mapper/
total 0
crw------- 1 0 0 10, 236 Mar 25 12:39 control
lrwxrwxrwx 1 0 0 7 Mar 25 12:39 fabienm-root -> ../dm-0
在启动的 linux (3.16-2-amd64) 下我有：
$ ls -l /dev/mapper/
total 0
crw------- 1 root root 10, 236 mars 25 13:44 control
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-home -> ../dm-5
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-root -> ../dm-0
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-swap_1 -> ../dm-3
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-tmp -> ../dm-4
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-usr -> ../dm-1
lrwxrwxrwx 1 root root 7 mars 25 13:44 fabienm-var -> ../dm-2
和 ：
$ grep dm_mod /proc/modules
dm_mod 89373 20 - Live 0xffffffffa021f000