TOPICS:
1. Creating Logical Volumes Using LVM
2. Disk Quota Implementation in Linux
3. Linux Bonding
4. Swap Space Partition/Files Provisioning
5. Linux Boot Process
6. Implementing RAID on Linux
7. Kernel Upgrade
1. CREATING LOGICAL VOLUMES USING LVM
1. Create LVM partitions via fdisk or parted
‘fdisk /dev/sda’ ‘fdisk /dev/sdb’, ‘fdisk /dev/sdc’
Press ‘ n’
Press ‘p’
Specify the size – ‘+10G’
Press ‘t’ – to change to type ‘8e’ (LVM)
Press ‘w’
$ partprobe /dev/sda # Repeat for /dev/sdb & /dev/sdc
2. Create physical volumes using ‘pvcreate’
$ pvcreate /dev/sda1
$ pvcreate /dev/sdb1
$ pvcreate /dev/sdc1
$ pvdisplay # To Display the Created physical Volumes
3. Create Volume Groups using ‘vgcreate’
$ vgcreate volgoup001 /dev/sda1 /dev/sdb1 /dev/sdc1
4. Create one or more logical volumes in that volume group
$ lvcreate -L 10GB -n lvpartition1 volgroup001
5. Create ext3 filesystem on Logical Volumes
$ mke2fs -j /dev/volgroup001/lvpartition1
6. Mount Logical Volumes
$ mkdir /dir1
$ mount /dev/volgroup001/lvpartition1 /dir1
2. DISK QUOTA IMPLEMENTATION IN LINUX
Following are the features of Implemeting Quotas:
1. Limits disk usage (With respect to Blocks and/or Inodes).
2. Tied to a File System ( Set on a per filesystem basis).
3. It can be configured for users and groups.
Steps to enable Quota Support:
1. Enable Quota support for File system in ’/etc/fstab’
/dev/sdb1 /home ext3 defaults,usrquota,grpquota 1 1
2. Remount the file system
$ mount -o remount /home #To remount ‘/home’ filesystem
$ mount # To verify and check
3. Create Quota database files and generate disk usage table
$ quotacheck -cug /home #Create Quota files
$ quotacheck -avug /home # To verify
4. Assign Quota Policy
$ edquota username # Set Blocks/Inodes Soft_Limit Hard_limit per User
$ edquota -g groupname # Set Quotas on groups
5. Check Quotas
$ quota username # Quota Per User
3. LINUX BONDING
Step 1:
$ cat /etc/sysconfig/network-scripts/ifcfg-bond0
DEVICE=bond0
IPADDR=192.168.1.12
NETMASK=255.255.255.0
GATEWAY=192.168.1.1
USERCTL=no
BOOTPROTO=none
ONBOOT=yes
Step 2.
Modify eth0, eth1 and eth2 configuration as shown below. Comment out, or remove the ip address, netmask, gateway and hardware address from each one of these files, since settings should only come from the ifcfg-bond0 file above.
$ cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=none
ONBOOT=yes
# Settings for Bond
MASTER=bond0
SLAVE=yes
$ cat /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
BOOTPROTO=none
ONBOOT=yes
# Settings for Bond
MASTER=bond0
SLAVE=yes
$ cat /etc/sysconfig/network-scripts/ifcfg-eth2
DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
# Settings for Bond
MASTER=bond0
SLAVE=yes
Step 3:
Set the parameters for bond0 bonding kernel module. Add the following lines to /etc/modprobe. conf
# bonding commands
alias bond0 bonding
options bond0 mode=balance-alb miimon=50
Step 4:
Load the bond driver module from the command prompt.
$ modprobe bonding
Step 5:
Restart the network, or restart the computer.
$ service network restart # Or restart computer
When the machine boots up check the proc settings.
$ cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.0.2 (March 23, 2006)
Bonding Mode: adaptive load balancing
Primary Slave: None
Currently Active Slave: eth2
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0
Slave Interface: eth2
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:13:72:80: 62:f0
Look at ifconfig -a and check that your bond0 interface is active. You are done
4. Swap Space (Partition/Files) Provisioning
STEP 1:
Check the current Swap space using following commands:
$ free -m
$ swapon -s
STEP 2:
Select target drive and create Swap Partition with Parition ID ‘82′
$ fdisk /dev/sdc
Press ‘n’
Press ‘2′
# Enter the Size of the partition,
Type ‘ +1024M’
Press ‘t’ # To change the type of partition
type ‘82′
Press ‘w’
$ Partprobe /dev/sdc
STEP 3:
Create a Swap Filesystem on newly created partition.
$ mkswap /dev/sdc1
STEP 4:
Enable swapping
$ swapon /dev/sdc1
STEP 5:
Update /etc/fstab to persist Swap space across reboots.
/dev/sdc1 swap swap defaults 1 1
Creating Swap space based on File
1. $ dd if=swap of=/home/swapfilespace1 bs=1024 count=524288
2. $ mkswap /home/swapfilespace1
3. $ swapon /home/swapfilespace1
5. LINUX BOOT PROCESS
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Title: LINUX BOOT PROCESS
####################################
5 STEP PROCESS:
1. BIOS loads & checks peripherals & checks for the boot device.
- Loads boot sector from one of the following:
- CDROM
- HARD DISK
- FLOPPY
- Executes first 512 bytes of the disk.
2. MBR will:
- look for primary partition marked bootable.
- loads and executes first 512 bytes of this partition, Which calls the stage 2 boot loader (GRUB/LILO).
3. GRUB:
- Is loaded into Memory.
- Locates kernel (vmlinuz) from /boot partition.
- Creates RAMDISK for initrd.
- Hands-off to kernel.
4. Kernel:
- Initializes devices.
- Mounts root file system.
- Excutes init process.
5. Init Process:
- Reads /etc/inittab
- Executres initialization scripts /etc/rc.d/rc/sysinit
- Loads deamons and mounts partitions (/etc/fstab)
User recieves login screen.
