Lab 6 Adding New Filesystems to the Filesystem Tree
Goal: Develop skills and knowlege related to partitioning and filesystems
Estimated Duration: 60 minutes
Sequence 1: Creating and Mounting Filesystems
Instructions:
1. Use fdisk -l to locate information about your harddisk. Depending on hardware you will see either a /dev/sda or /dev/hda disk. Partition sizes are given in cylinders.
2. Now use fdisk to add a new logical partition that is 1GB to 2GB in size. Create an extended partition (if necessary) that uses the rest of the drive before creating the logical partition. (Make sure to write the changes to disk using the w command.). Run fdisk -l to verify that the partition was created.
fdisk requires a single disk device as parameter. If your workstation is equipped with a SATA drive this is /dev/sda. Otherwise use /dev/hda.
# fdisk /dev/hda
The following commands are all within fdisk:
a. Within fdisk, type p to print the current partition table. Verify that the drive already has an extended partition. If there is none, create one that spans the rest of the disk now:
• Press n for a new partition
• e to create an extended partition
• 4 as the partition number
• First cylinder: First unused cylinder is default, so type Enter here
• Last cylinder: Last cylinder of disk is default, press Enter
b. Create a new logical partition.
• n for a new partition
• l (the letter L) to create an logical partition (skipped if no primary partitions left)
• First cylinder: Enter
• Last cylinder: +1024M
c. Write the new partition table with w. This will also terminate the fdisk command
3. Run cat /proc/partitions. Why does the new partition not show up?
The kernel has not reread its partition table
4. Reboot to reread the revised partition table or use partprobe to refresh the kernel's view of the partition table.
5. Create an ext3 filesystem on the new partition. Use 2 KB sized blocks and one inode per every 4 KB of disk space. Assign the label opt to the filesystem, mount it on the filesystem tree at /opt. Make sure that the system mounts this filesystem after reboot.
The example solution uses the mkfs.ext3 command. mke2fs with the -j option could have also been used. The -L option sets the filesystem label, we could have just as easily used a separate call to e2label after we created the filesystem. As is the case with just about all our examples, there is more than one way to do it.
a. # mkfs.ext3 -L opt -b 2048 -i 4096 device
b. # mkdir /opt
c. Edit /etc/fstab:
LABEL=opt /opt ext3 defaults 1 2
d. Use the mount -a command to mount the new file system on /opt. Were there any errors? If so check the syntax of the /etc/fstab and try again. Use the mount command, this time with no options, to confirm that /opt mounted properly. Copy /
etc/passwd into /opt and verify that the copy was successful.
e. Reboot the system to verify that the filesystem is automatically mounted after boot.
6. CLEANUP:
a. Unmount /opt and comment out the line in /etc/fstab that references /opt.
# umount /opt
b. Edit /etc/fstab:
#LABEL=opt /opt ext3 defaults 1 2
c. Use fdisk to delete the partition you just created. Hint: The last partition created will be the partition with the highest number.
Run fdisk on the disk device from earlier in the unit.
# fdisk /dev/hda
(Following commands are all within fdisk.)
d. Delete the last partition on the list.
• d for a delete partition
• Choose the highest number listed. For example, if it says:
Partition Number (1-5):
Choose 5
• Write the new partition table with w. This will also terminate the fdisk command
e. Run partprobe to refresh the kernel's view of the partition table.
Sequence 2: Mounting an NFS Filesystem
Instructions:
1. Ensure that iptables firewalling is disabled.
# service iptables stop
# chkconfig iptables off
2. Mount the export server1:/var/ftp/pub persistently at /mnt/server1.
a. # mkdir /mnt/server1
b. Edit /etc/fstab:
server1:/var/ftp/pub /mnt/server1 nfs defaults 0 0
c. Use the mount -a command to mount the export on /mnt/server1 and check for errors in the /etc/fstab
d. Reboot your system to test.
# init 6
Sequence 3: Automounting data with autofs
Instructions:
1. Ensure that iptables firewalling is disabled.
# service iptables stop
# chkconfig iptables off
2. Configure automounter to mount server1:/var/ftp/pub to /misc/server1.
a. Edit the /etc/auto.master file. Uncomment the first line for /misc.
b. Add a line to the /etc/auto.misc file that will mount the /var/ftp/pub export from server1.example.com to your own /misc/server1 target:
server1 -ro,intr,hard server1:/var/ftp/pub
c. Restart the autofs service:
# service autofs restart
d. Try to access the /misc/server1 directory.
3. Use the automounter to mount the home directories for your NIS users from server1.example.com. You can use getent passwd to see what home directories are assigned. server1.example.com exports /home/guests to your system.
a. Begin by editing /etc/auto.master and add the following line:
/home/guests /etc/auto.guests --timeout=60
This line specifies that /etc/auto.guests defines mount points in /home/guests managed by the automounter. When not in use for more than 60 seconds, filesystems mounted on those mount points are automatically unmounted.
b. Create and edit /etc/auto.guests so it contains the line
* -rw,soft,intr 192.168.0.254:/home/guests/&
This line specifies that access to any immediate subdirectory of /home/guests should make autofs mount a NFS export from 192.168.0.254 where the & is the same as the name of the local subdirectory. (So the automounter would mount 192.168.0.254:/home/guests/guest2001 on /home/guests/ guest2001). The middle column specifies the mount options that will be used; readwrite, timeout eventually if the NFS server is not available, and timeout immediately if an interrupt is sent.
c. Configure autofs to start in run levels 2, 3, 4, and 5, then restart it manually:
[root@stationX]# chkconfig autofs on ; service autofs restart
d. Now try logging in again and see whether the home directory gets mounted automatically. It should. Try logging into to your neighbors system once it is also configured. You should be able to access your home environment from any system in the notexample domain.