On Friday 01,October,2010 12:23 PM, Dennis Cao wrote: > Hi buddies, > > I want to install GRUB2 on my USB disk, so that I can boot my computer > if my system crashes. > > I read manual of GRUB2 and tried to understand what grub-install did, > especially the '--root-directory' parameter. The manual says: > "... .... If you want GRUB to use images under a directory other > than the root directory, you need to specify the option > --root-directory .... ...." > > I think grub-install first creates and installs 'boot.img' to MBR. And > it hardcodes the location of core.img inside boot.img. So, does > '--root-directory' tells grub-install to use core.img in the specific > directory? > > Another question. I use the following command to try to install grub > to my usb disk. > grub-install --root-directory=/boot /dev/hdb > But when I boot my computer from USB disk, my computer just stops > after printing 'GRUB' on the left-top conner of the screen :( > > Can anybody explain the details and usage of grub-install command? > What does it do? Which images are used and where are they copied to on > the hard or usb disk? > > Thanks in advence:) > On Friday 01,October,2010 12:23 PM, Dennis Cao wrote: > > Hi buddies, > > > > I want to install GRUB2 on my USB disk, so that I can boot my computer > > if my system crashes. > > > > I read manual of GRUB2 and tried to understand what grub-install did, > > especially the '--root-directory' parameter. The manual says: > > "... .... If you want GRUB to use images under a directory other > > than the root directory, you need to specify the option > > --root-directory .... ...." > > > > I think grub-install first creates and installs 'boot.img' to MBR. And > > it hardcodes the location of core.img inside boot.img. So, does > > '--root-directory' tells grub-install to use core.img in the specific > > directory? > > > > Another question. I use the following command to try to install grub > > to my usb disk. > > grub-install --root-directory=/boot /dev/hdb > > But when I boot my computer from USB disk, my computer just stops > > after printing 'GRUB' on the left-top conner of the screen :( > > > > Can anybody explain the details and usage of grub-install command? > > What does it do? Which images are used and where are they copied to on > > the hard or usb disk? > > > > Thanks in advence:) > >
曹贵林, "grub-install --root-directory=/boot /dev/hdb" does not make a grub.cfg (menu) for you. You have to recreate the grub.cfg manually or just copy the original and modify the grub.cfg. Before we talk about modifying the grub.cfg, you used "dev/hdb". Please check first if it is really "hdb" or "sdb" by either "sudo fdisk -l" or "sudo blkid". Also when you do that note the uuid number of the usb disk. Then after you do the "sudo grub-install --root-directory=/boot /dev/hdb" or most likely "sudo grub-install --root-directory=/boot /dev/sdb", copy over the /boot/grub/grub.cfg to the usb's /boot/grub/grub.cfg and modify as follows... >> >> Modifying the grub.cfg at /media/usb/grub/........ > > > > To modify the grub.cfg, all entries before the d/10_linux entries can be > > deleted with the exception of the following > > > > set default=0 > > set timeout=7 > > insmod ext2 > > set root=(hd0,x) > > search --no-floppy --fs-uuid --set xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > > > > if loadfont /usr/share/grub/ascii.pf2 ; then > > set gfxmode=1152x864 > > insmod gfxterm > > insmod vbe > > if terminal_output gfxterm ; then true ; else > > # For backward compatibility with versions of terminal.mod that don't > > # understand terminal_output > > terminal gfxterm > > fi > > fi > > > > set menu_color_normal=cyan/blue > > set menu_color_highlight=yellow/blue > > > > > > It is highly recommended that the following 2 functions be deleted from > > the grub.cfg > > function savedefault > > function recordfail > > > > The following can also be deleted unless you want to use non-english > > text for grub (or it can be left untouched) > > set locale_dir= > > set lang=en > > insmod gettext > > > > > > *important note* > > the above two lines (lines #7 and #8) with (hd0,x) and UUID, please > > substitute with (hd0,x) and UUID of /media/usb. 曹贵林, hope this is what you are looking for. There are further modifications to 'improve' automatic booting of any kernel changes at .. http://forum.nginx.org/read.php?26,67573 Regards - Goh Lip - �橇� _______________________________________________ Help-grub mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-grub
