安裝完Ubuntu 9.04啟動到grub時出現waiting for loading…後提示找不到root device，然後跳入initramfs，這時如果運行exit可以進入系統說明rootdelay時間太短了，解決辦法：
sudo vi /boot/grub/menu.lis
可以看到要啟動的grub項目：
## ## End Default Options ##
title Ubuntu 9.04, kernel 2.6.28-11-server
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /vmlinuz-2.6.28-11-server root=/dev/mapper/shangri–la-root ro quiet splash
initrd /initrd.img-2.6.28-11-server
quiet
title Ubuntu 9.04, kernel 2.6.28-11-server (recovery mode)
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /vmlinuz-2.6.28-11-server root=/dev/mapper/shangri–la-root ro single
initrd /initrd.img-2.6.28-11-server
title Ubuntu 9.04, memtest86+
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /memtest86+.bin
quiet
這裡在第一項裡面的kernel行中加入rootdela=90如下：
## ## End Default Options ##
title Ubuntu 9.04, kernel 2.6.28-11-server
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /vmlinuz-2.6.28-11-server root=/dev/mapper/shangri–la-root ro quiet splash rootdelay=90
initrd /initrd.img-2.6.28-11-server
quiet
title Ubuntu 9.04, kernel 2.6.28-11-server (recovery mode)
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /vmlinuz-2.6.28-11-server root=/dev/mapper/shangri–la-root ro single
initrd /initrd.img-2.6.28-11-server
title Ubuntu 9.04, memtest86+
uuid c757c22c-b798-433a-b284-8bca8e084406
kernel /memtest86+.bin
quiet
重啟後正常。
