--- In [email protected], "navin.karmarkar" <navin.karmar...@...> wrote: > > hi navin here ... plz tell me in boot process in lilo we have 4 files 1 ) map > 2 ) message 3 ) initrd 4 )boot.b , but now in grub concept there is no such > file called boot.b but there are 2 files in /boot called stage1 and stage 2 > are they replacement for boot.b ? >
Dear All, BookMark the following, very useful. (Using Grub) Refrence http://members.iinet.net.au/~herman546/p15.html Grub has 3 stages satge 1 stage 1.5 & stage 2,, note -: 1.5 is optional, GRUB consists of several images: two essential stages, optional stages called Stage 1.5, one image for bootable CD-ROM, and two network boot images. Here is a short overview of them. See Internals, for more details. stage1 This is an essential image used for booting up GRUB. Usually, this is embedded in an MBR or the boot sector of a partition. Because a PC boot sector is 512 bytes, the size of this image is exactly 512 bytes. All stage1 must do is to load Stage 2 or Stage 1.5 from a local disk. Because of the size restriction, stage1 encodes the location of Stage 2 (or Stage 1.5) in a block list format, so it never understand any filesystem structure. stage2 This is the core image of GRUB. It does everything but booting up itself. Usually, this is put in a filesystem, but that is not required. e2fs_stage1_5 fat_stage1_5 ffs_stage1_5 jfs_stage1_5 minix_stage1_5 reiserfs_stage1_5 vstafs_stage1_5 xfs_stage1_5 These are called Stage 1.5, because they serve as a bridge between stage1 and stage2, that is to say, Stage 1.5 is loaded by Stage 1 and Stage 1.5 loads Stage 2. The difference between stage1 and *_stage1_5 is that the former doesn't understand any filesystem while the latter understands one filesystem (e.g. e2fs_stage1_5 understands ext2fs). So you can move the Stage 2 image to another location safely, even after GRUB has been installed. While Stage 2 cannot generally be embedded in a fixed area as the size is so large, Stage 1.5 can be installed into the area right after an MBR, or the boot loader area of a ReiserFS or a FFS. Which Is Better? GRUB or LILO LILO is older and less powerful. Originally LILO did not include a GUI menu choice (but did provide a text user interface). To work with LILO an administrator has many tasks to perform in addition to editing the configuration files. GRUB is a bit easier to administer because the GRUB loader is smart enough to locate the /boot/grub/grub.conf file when booting. An administrator only needs to install GRUB once, using the "grub-install" utility. Any changes made to grub.conf will be automatically used when the system is next booted. In contrast, any changes made to lilo.conf are not read at boot time. The MBR needs to be "refreshed." Like GRUB does, LILO has no interactive command interface and does not support booting from a network. If LILO MBR is configured correctly, the LILO system becomes unbootable. If the GRUB configuration file is configured incorrectly, it will default to the GRUB command-line interface without risking of making the system unbootable. LILO and GRUB allows users—the root users—to boot into single-user mode. Both have a password protection feature with a difference. While GRUB allows for MD5 encrypted passwords, LILO manages only text passwords, which anyone can read from the lilo.conf file with the command cat /etc/lilo.conf. For the novice, start with LILO and then migrate to GRUB. B.Sadhiq
