How to extend instance storage on Amazon EC2
I’ve just launched an EC2 instance from my own AMI. This time however I wanted it to have more storage so I increased the size of my disk space from 10 to 100GB.
Once the instance had launched I’ve noticed that – as before – only 10GB was actually available.
I’ve had this with other infrastructure before, and I knew that I had to extend the volume as well as the volume and the file system for the OS to recognise the extra space.
df -h Filesystem Size Used Avail Use% Mounted on /dev/xvde1 9.9G 2.6G 6.9G 27% / tmpfs 1.8G 0 1.8G 0% /dev/shm
What puzzled me was the following error message when using the lvextend command:
lvextend -L +97G /dev/xvde Path required for Logical Volume "xvde" Please provide a volume group name Run `lvextend --help' for more information.
Was I not using the command correctly? Had I miscalculated the space I had in addition? I checked again with fdisk -l:
fdisk -l Disk /dev/xvde1: 107.4 GB, 107374182400 bytes 255 heads, 63 sectors/track, 13054 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: 0x00000000 Disk /dev/xvdj: 5368 MB, 5368709120 bytes 255 heads, 63 sectors/track, 652 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: 0x00000000
Nope, I was right – but lvextend wasn’t happy.
Amazon had already extended the volume – all I had to do was grow the file system:
resize2fs /dev/xvde1 resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/xvde1 is mounted on /; on-line resizing required old desc_blocks = 1, new_desc_blocks = 7 Performing an on-line resize of /dev/xvde1 to 26214400 (4k) blocks. The filesystem on /dev/xvde1 is now 26214400 blocks long.
Let’s check it out:
df -h Filesystem Size Used Avail Use% Mounted on /dev/xvde1 99G 2.6G 91G 3% / tmpfs 1.8G 0 1.8G 0% /dev/shm
Sometimes things are actually easier than we think 😉