Many times you will purchase a VPS and go with the lowest resources you think you can get away with. As your website grows you may find you need to add more disk space.
This can be very easy to do with some basic tools in Linux. I will show you how to quickly and easily do this in Debian – but you shouldn’t have issue doing this in any other distro that includes fdisk and resize2fs.
First, you will need to have your disk expanded in the backend. This will have to be done by the VPS provider. Once the disk has been expanded you will want to reboot the machine. This will allow fdisk to see the larger disk.
Before reboot:
# fdisk -ls Disk /dev/sda: 85.9 GB, 85899345920 bytes 255 heads, 63 sectors/track, 10443 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: 0x000c64d7 Device Boot Start End Blocks Id System /dev/sda1 1 12 96358+ 83 Linux /dev/sda2 13 498 3903795 82 Linux swap / Solaris /dev/sda3 499 10443 79883212+ 83 Linux
After reboot:
# fdisk -ls Disk /dev/sda: 161.1 GB, 161061273600 bytes 255 heads, 63 sectors/track, 19581 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: 0x000c64d7 Device Boot Start End Blocks Id System /dev/sda1 1 12 96358+ 83 Linux /dev/sda2 13 498 3903795 82 Linux swap / Solaris /dev/sda3 499 10443 79883212+ 83 Linux
The next step is to delete the current partition, and recreate it with the new larger size. Do not worry, the process of deleting a partition doesn’t actually remove any data, just the reference to the partition.
So run:
fdisk /dev/sda
Where sda is the disk in question.
The first command to run is: p which simply prints the current partition table.
Command (m for help): p Disk /dev/sda: 161.1 GB, 161061273600 bytes 255 heads, 63 sectors/track, 19581 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: 0x000c64d7 Device Boot Start End Blocks Id System /dev/sda1 1 12 96358+ 83 Linux /dev/sda2 13 498 3903795 82 Linux swap / Solaris /dev/sda3 499 10443 79883212+ 83 Linux
Make note of the start number for the partition you want to expand, which is sda3 and start #:499 in my case.
So next delete the partition:
Command (m for help): d Partition number (1-4): 3
Next, create a new partition using the same starting cylinder, but change the end to be the size you want the disk to be. Which in my case is as big as it can get (or 19581):
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (499-19581, default 499):
Using default value 499
Last cylinder, +cylinders or +size{K,M,G} (499-19581, default 19581):
Using default value 19581
I just hit enter for the first and last cylinder, as it defaults to the next available one for the start, and the last for the end.
Next, you will have to reboot the machine. This lets the machine re-read the partition table.
reboot
Now that the partition has been expanded, it is time to resize the ext3 file system. This may work on ext4, but I haven’t tested it. This is a simple one line command:
# resize2fs /dev/sda3 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/sda3 is mounted on /; on-line resizing required old desc_blocks = 5, new_desc_blocks = 10 Performing an on-line resize of /dev/sda3 to 38321049 (4k) blocks. The filesystem on /dev/sda3 is now 38321049 blocks long.
This is pretty much magic in my book.
# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 144G 65G 73G 48% / tmpfs 1.5G 0 1.5G 0% /lib/init/rw udev 1.5G 104K 1.5G 1% /dev tmpfs 1.5G 0 1.5G 0% /dev/shm /dev/sda1 92M 38M 49M 44% /boot
Beautiful and simple isn’t it? That’s all folks!
#1 by Suat on May 2, 2014 - 4:11 am
Thank you! Straight and flawless explanation. Worked like a charm!
Only one tiny little point took my attention: after creating the new partition, just before the reboot, it – naturally – gives an error saying “WARNING: Re-reading the partition table failed with error 16: Device or resource busy.” and at first look, it made me feel like it failed. But after reading next lines of the error it says it needs to reboot and makes sense that it just needs to do that, however that WARNING indicator is really annoying as a newbie linux user like something didn’t go well. Lesson learned from this experience once again: always read the messages until the end and make sure to understand what it actually means :)
Thanks again.