Information Technology Reference
In-Depth Information
Recovering the root or /usr File System
Occasionally, the root or
/usr
file system needs to be recovered. Assuming
that the file system has been backed up and that the backup is available, the
following procedure can be used:
1.
Select an available partition or, if additional hardware is required,
install the new disk in the system and then format and create an appro-
priately sized partition.
2.
Create a file system using the
newfs
command or another command
(such as the
mkfs
command).
3.
Mount the new file system on a temporary mount point. Then change
the directory to the temporary mount point.
4.
Use the
ufsrestore
command to restore the root or
/usr
backup to
the new file system.
5.
Remove the
restoresymtable
created by the
ufsrestore
command to
check point the restore.
6.
Unmount the new file system.
7.
Use the
fsck
command to check the new file system. Modify the
/etc/vfstab
file to identify the new root or
/usr
partition.
8.
If recovering the root file system, use the
installboot(1M)
command
to create a boot block on the new file system.
9.
Reboot the system.
Other Backup/Restore Utilities
Several other commands are used for backup/restore operations. These
include the
tar(1)
and
cpio(1)
commands to create archives of files and
directories that can be restored on another system. The
find(1)
command
can used to select file/directories based on specified characteristics (such as
filename, file type, and so on).
The tar Command
The
tar(1)
command is used to create a tape archive and to add or extract
files from the archive. Table 8.4 lists the five basic functions of the
tar
com-
mand.
