Resizing Existing Hard Drive Storage
You can upgrade the storage on your Server at any time by using the "Resize" function in My Account. When upgrading a disk there are a few important considerations. Sometimes customers are unable to view their new storage because the operating system does not automatically recognise the new space. There are different commands for each operation system Windows, Ubuntu, Redhat/Fedora and CentOS.
Unallocated Space
Please note that any unallocated space that is added to the primary partition can not be removed. All partitions (other than the primary) can be deleted and the unallocated space can be re-allocated. To get your new space allocated to your Cloud Server please see the following quick help notes.
Windows
Please use the Microsoft Windows Disk Manager to scan and engage the changed drive space.
Ubuntu
For a New Disk:
echo "- - -" > /sys/class/scsi_host/host0/scan fdisk /dev/sdb press "n" then "p" then "1", then "1", then press enter, then press "t", then type in "8e" and press return, then press "w" pvcreate /dev/sdb1 type "vgdisplay", note down the "VG Name" vgextend /dev/sdb1 lvdisplay, note down the logical volume you want to extend lvextend /dev/sdb1 resize2fs
For an Extended Disk:
blockdev --rereadpt /dev/sda fdisk pvcreate /dev/sdaX type "vgdisplay", note down the "VG Name" vgextend /dev/sdb1 lvdisplay, note down the logical volume you want to extend lvextend /dev/sdb1 resize2fs
Fedora/Red Hat Linux
fdisk /dev/sdb Enter "n" Enter "p" 1 Enter "w" mkfs -t ext3 /dev/sdb mkdir /DIRECTORY e2label /dev/sdb /DIRECTORY echo "LABEL=/DIRECTORY /DIRECTORY ext3 defaults 1 2" >> /etc/fstab mount LABEL=/DIRECTORY /DIRECTORY ;
Replace /DIRECTORY with whatever directory you want to mount /dev/sdb to.
For Centos
In this example, a Centos6 partition using LVM will be expanded from 20GB to 30GB. Note, a reboot of the VM may be required in order for the additional disk space to be made available to the operating system.
Check existing partitions
[root@centos6 ~]# fdisk -l Disk /dev/sda: 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: 0x0003468a
Run fdisk on the existing disk to create a new partition. Select option ?n? to create a new partition, followed by option p for a primary partition, select a partition number (3 in this example). Use default first and last cylinder values.
[root@centos6 ~]# fdisk /dev/sda WARNING: DOS-compatible mode is deprecated. It"s strongly recommended to switch off the mode (command "c") and change display units to sectors (command "u"). Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 3 First cylinder (2611-3916, default 2611): Using default value 2611 Last cylinder, +cylinders or +size{K,M,G} (2611-3916, default 3916): Using default value 3916
Print partition table using ?p? to see the new partition.
Command (m for help): p Disk /dev/sda: 32.2 GB, 32212254720 bytes 255 heads, 63 sectors/track, 3916 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: 0x0003468a Device Boot Start End Blocks Id System /dev/sda1 * 1 64 512000 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 64 2611 20458496 8e Linux LVM /dev/sda3 2611 3916 10483750 83 Linux
Change partition type to LVM.
Command (m for help): t Partition number (1-4): 3 Hex code (type L to list codes): 8e Changed system type of partition 3 to 8e (Linux LVM)
Save changes using ?w?.
Command (m for help): w 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 the host.
[root@centos6 ~]# shutdown -r now Broadcast message from root@centos6 (/dev/pts/0) at 12:48 ... The system is going down for reboot NOW!
Scan the volume
[root@centos6 ~]# pvscan PV /dev/sda2 VG vg_centos6 lvm2 [19.51 GiB / 0 free] Total: 1 [19.51 GiB] / in use: 1 [19.51 GiB] / in no VG: 0 [0 ]
Extend volume group to include new partition,
[root@centos6 ~]# vgextend vg_centos6 /dev/sda3 No physical volume label read from /dev/sda3 Writing physical volume data to disk "/dev/sda3" Physical volume "/dev/sda3" successfully created Volume group "vg_centos6" successfully extended
Run pvscan again to see the new partition included as part of the volume group.
[root@centos6 ~]# pvscan PV /dev/sda2 VG vg_centos6 lvm2 [19.51 GiB / 0 free] PV /dev/sda3 VG vg_centos6 lvm2 [10.00 GiB / 10.00 GiB free] Total: 2 [29.50 GiB] / in use: 2 [29.50 GiB] / in no VG: 0 [0 ]
Extend the logical volume to include the new disk space using lvextend command.
root@centos6 ~]# lvextend -L +9.99G /dev/vg_centos6/lv_root Rounding size to boundary between physical extents: 9.99 GiB Extending logical volume lv_root to 25.56 GiB Logical volume lv_root successfully resized
Finally, extend the ext4 file system so it can use the extra space.
[root@centos6 ~]# resize2fs /dev/vg_centos6/lv_root resize2fs 1.41.12 (17-May-2010) Filesystem at /dev/vg_centos6/lv_root is mounted on /; on-line resizing required old desc_blocks = 1, new_desc_blocks = 2 Performing an on-line resize of /dev/vg_centos6/lv_root to 6701056 (4k) blocks. The filesystem on /dev/vg_centos6/lv_root is now 6701056 blocks long.
Verify the new space is available.
[root@centos6 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_centos6-lv_root 26G 1.1G 23G 5% / tmpfs 939M 0 939M 0% /dev/shm /dev/sda1 485M 52M 408M 12% /boot
Original credit Increasing CentOS LVM under VMware by Red Branch