Today I’ve learnt that a Linux partition (which is mounted) can be grown “a la brava” (means “the hard way” in Catalan) directly modifying it through Fdisk and then resizing with resize2fs. That’s it….
With my own conservative way I’d boot the machine into Gparted (A very useful small distro that boots into Gparted directly), resize the partition (unmounted), and then reboot again.
The only condition is that the partition which has to be grown is the last one. If not… things get more complicated (or not, if the last partition is a swap one, which can be erased and recreated without problems). Other condition is that particion can only be grown (not shrink).
The process it’s easy:
- First grow the disk physically (can be a VM disk, a new bigger disk just cloned, or simply a partition that does’nt fill the entire disk).
- With Fdisk, remove the partition.
- Without exiting Fdisk, create a new partition. Carefully note that the first sector match the previous first sector. The last sector can be the end of the disk i.e.
- Verify/toggle Boot flag, must be activated.
- Save and exit. Cross your fingers and reboot.
- Once rebooted, grow the filesystem with resize2fs.
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## 4.3Gb of free space before the process root@nairobi:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda2 11G 5.7G 4.3G 57% / udev 238M 4.0K 238M 1% /dev tmpfs 49M 176K 49M 1% /run none 5.0M 0 5.0M 0% /run/lock none 245M 0 245M 0% /run/shm ## Let's do it ## (Note that HDD is 26.8 Gb. It has been grown previously at XEN dom0 level). root@nairobi:~# fdisk /dev/xvda Command (m for help): p Disk /dev/xvda: 26.8 GB, 26843545600 bytes 255 heads, 63 sectors/track, 3263 cylinders, total 52428800 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00088b81 Device Boot Start End Blocks Id System /dev/xvda1 2048 999423 498688 82 Linux swap / Solaris /dev/xvda2 * 999424 23068671 11034624 83 Linux Command (m for help): d Partition number (1-4): 2 # Remove the last partition. DON'T WRITE CHANGES YET! # And re-create the partition. Note that first sector MUST be the same than before # In my case 999424. If in your case doesn't match for whatever reason, ABORT HERE! Command (m for help): n Partition type: p primary (1 primary, 0 extended, 3 free) e extended Select (default p): p Partition number (1-4, default 2): Using default value 2 First sector (999424-52428799, default 999424): Using default value 999424 Last sector, +sectors or +size{K,M,G} (999424-52428799, default 52428799): Using default value 52428799 Command (m for help): p Disk /dev/xvda: 26.8 GB, 26843545600 bytes 255 heads, 63 sectors/track, 3263 cylinders, total 52428800 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00088b81 Device Boot Start End Blocks Id System /dev/xvda1 2048 999423 498688 82 Linux swap / Solaris /dev/xvda2 999424 52428799 25714688 83 Linux # Don't forget to toggle bootable flag ON: (Which after the change has been lost) Command (m for help): a Partition number (1-4): 2 Command (m for help): wq The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. # Reboot, cross your fingers... wait... log again and resize filesystem root@nairobi:~# resize2fs /dev/xvda2 resize2fs 1.42 (29-Nov-2011) Filesystem at /dev/xvda2 is mounted on /; on-line resizing required old_desc_blocks = 1, new_desc_blocks = 2 Performing an on-line resize of /dev/xvda2 to 6428672 (4k) blocks. The filesystem on /dev/xvda2 is now 6428672 blocks long. # Voilà!! root@nairobi:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda2 25G 5.7G 18G 25% / udev 238M 4.0K 238M 1% /dev tmpfs 49M 176K 49M 1% /run none 5.0M 0 5.0M 0% /run/lock none 245M 0 245M 0% /run/shm |