An Addition to Adeel Ahmad's Answer:
If you are attempting to start an instance from an AMI with a swap partition, then additional steps will have to be performed.
For example, if the ami contains as follows:
# fdisk -l
Disk /dev/xvde: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xe211223f
Device Boot Start End Blocks Id System
/dev/xvde1 * 1 1291 10369926 83 Linux
/dev/xvde2 1292 1305 112455 82 Linux swap / Solaris
If I have to upgrade my capacity to 20GB, i will create an AMI and try to launch another instance with 20GB space. After this, if i try the above steps, the disk space wont increase as there is a xvde2 partition in-between the xvde1 and the new space.
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvde1 9.8G 7.5G 1.8G 81% /
$ fdisk -l
Disk /dev/xvde: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xe211223f
Device Boot Start End Blocks Id System
/dev/xvde1 * 1 1291 10369926 83 Linux
/dev/xvde2 1292 1305 112455 82 Linux swap / Solaris
$ resize2fs /dev/xvde1
resize2fs 1.41.12 (17-May-2010)
The filesystem is already 2592481 blocks long. Nothing to do!
In this case do the following
- Delete both the partitions
- Create new Primary partition with the new required size minus the size for swap space
- Add bootable flag for this partition
- Create second partition
- Mark it as swap
- write changes and reboot
- Extend partition 1
- Setup swap
OR
Deleting partition 1 Selected partition 1
Command (m for help): d <<6>>
Partition number (1-4): 1 <<6.0.1>>
Deleting partition 2 Selected partition 2
Command (m for help): d <<6.2>>
Creating resized primary partition 1
Command (m for help): n <<7>>
Command action
e extended
p primary partition (1-4)
p <<8>>
Partition number (1-4): 1 <<9>>
First sector (17-41943039, default 17): 2048 <<10>>
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039):<<NEW_UPPER_LIMIT>> <<11>>
TAKE CARE : 2048 should be replaced by your original starting sector
or the system wont boot. NEW_UPPER_LIMIT will be the new sector number
for upper limit and the rest will be left for swap. For maintaining
the same swap space, Subtract the original start and end sector
numbers and then subtract the result from 41943039(or your upper
limit)
Creating swap partition
Command (m for help): n <<12>>
Command action
e extended
p primary partition (1-4)
p <<13>>
Partition number (1-4): 2 <<14>>
First sector (<<NEW_UPPER_LIMIT+1>>-41943039, default <<NEW_UPPER_LIMIT+1>>): <<USE_DEFAULT>> <<15>>
Last sector, +sectors or +size{K,M,G}(<<NEW_UPPER_LIMIT+1>>-41943039,default 41943039):<<USE_DEFAULT>> <<16>>
Using default value 41943039
Adding bootable bit for partition 1
Command (m for help): a <<17>>
Partition number (1-4): 1 <<18>>
Marking partition 2 as swap
Command (m for help): l <<19>>
Now you will see a list of filesystems. Note the one corresponding to Linux swap (say 82)
Command (m for help): t <<20>>
Partition number (1-4): 2 <<21>>
Hex Code (type l to list codes) : 82 <<22>>
Write changes and reboot
Command (m for help): w <<23>> The partition table has been altered!
....
$ sudo reboot
After reboot run
resize2fs /dev/xvde1
This will resize your fs
Now to use the second partition as swap
$ mkswap /dev/<<SECOND SWAP PARTITION(run fdisk -l to get the name)>>
$ swapon /dev/<<SECOND SWAP PARTITION(run fdisk -l to get the name)>>
You can check the /proc/swaps file to verify
$ cat /proc/swaps
Now add the following to the /etc/fstab for these changes to be persistent
At the end of /etc/fstab (open with nano or vi etc)
/dev/<<SECOND SWAP PARTITION>> swap swap defaults 0 0
Save and Exit
Reboot and check
resize2fsbe/dev/xvda1and not/dev/xvda? – Depress