The core.img file will normally be stored in the same location as Stage 1.5(GRUB Stage 1.5 is located in the first 30 kilobytes of hard disk immediately following the MBR and before the first partition)
Once loaded, the core.img file will load the default configuration file and any other modules needed in stage 2.
A journaling file system is a file system that keeps track of the changes that will be made in a journal (usually a circular log in a dedicated area of the file system) before committing them to the main file system. In the event of a system crash or power failure, such file systems are quicker to bring back online and less likely to become corrupted.
Comparisons of EXTs File system Maximum filename length Allowable characters in directory entries Maximum pathname length Maximum file size Maximum volume size ext2 255 bytes Any byte except NULL and / No limit defined 16 GB to 2 TB 2 TB to 32 TB ext3 255 bytes Any byte except NULL and / No limit defined 16 GB to 2 TB 2 TB to 32 TB ext4 256 bytes Any byte except NULL and / No limit defined 16 GB to 16 TB 1 EB (but user tools limited to 16 TB)
Root Directory Begins filesystem structure /usr Holds subdirectories that support user Administrative application libraries /media Used for mount points Mount CD-Rom, DVD,floppy
/mnt Used for mount points Mount filesystem (windows partition) /home Hold home directories Like user account /var Holds files and directories that frequently change Like web server files, log files, printer spool file