At some point my RHEL7 development virtual machine run out of space.
Resizing the image is really made easy by RedHat:
STEP 1: Resize the virtual machine disk
[root@localhost VMs]# qemu-img resize RHEL7-clone.qcow2 50G Image resized. [root@localhost VMs]#
STEP 2: Start the VM and check the disks from inside the VM
Check the virtual disk:
[root@test1 ~]# fdisk /dev/sda Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Command (m for help): p Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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 label type: dos Disk identifier: 0x0005ea5f Device Boot Start End Blocks Id System /dev/sda1 * 2048 1026047 512000 83 Linux /dev/sda2 1026048 41943039 20458496 8e Linux LVM
We can see here that the virtual disk size was updated to 53.7 GB. This is good it means that the qemu-img was successful.
Check the physical volume:
[root@test1 ~]# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name rhel PV Size 19.51 GiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 4994 Free PE 10 Allocated PE 4984 PV UUID mJKfU1-q4yd-XAUM-2nbd-SUeD-5Ogn-PVno7Z
We see here that we will need to extend this pv /dev/sda2.
Check the volume group
[root@test1 ~]# vgdisplay --- Volume group --- VG Name rhel System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 19.51 GiB PE Size 4.00 MiB Total PE 4994 Alloc PE / Size 4984 / 19.47 GiB Free PE / Size 10 / 40.00 MiB VG UUID NUJi9T-6QZd-vXsA-7VI4-sfP8-cjLt-np8Iiu
Check the logical volumes
[root@test1 ~]# lvdisplay --- Logical volume --- LV Path /dev/rhel/swap LV Name swap VG Name rhel LV UUID TDLETn-ngo9-L8aD-vF0g-K5W3-THs8-N2Yzlf LV Write Access read/write LV Creation host, time test1.voina.org, 2016-04-13 12:39:24 +0300 LV Status available # open 2 LV Size 2.00 GiB Current LE 512 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:1 --- Logical volume --- LV Path /dev/rhel/root LV Name root VG Name rhel LV UUID vwgcMf-EjDs-c3te-lDkl-VKSQ-491C-SPyzPe LV Write Access read/write LV Creation host, time test1.voina.org, 2016-04-13 12:39:25 +0300 LV Status available # open 1 LV Size 17.47 GiB Current LE 4472 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0
We see here that we want to extend the root logical volume /dev/rhel/root.
STEP 3: Allocate the extra space
First we have to resize the primary partition /dev/sda2. This can be done with parted resize.
The issue here is RHEL7 does not support parted resize see https://access.redhat.com/articles/1190213
There two alternatives. One is to delete and remake /dev/sda2, that is not an option here. The other is to simply create a new partition, create anew physical volume, add it to the volume group and extend the logical volume over it.
Create primary partition /dev/sda3, allocate all the space and make it of type LVM
[root@test1 ~]# fdisk /dev/sda
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p
Partition number (3,4, default 3):
First sector (41943040-104857599, default 41943040):
Using default value 41943040
Last sector, +sectors or +size{K,M,G} (41943040-104857599, default 104857599):
Using default value 104857599
Partition 3 of type Linux and of size 30 GiB is set
Command (m for help): p
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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 label type: dos
Disk identifier: 0x0005ea5f
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
/dev/sda3 41943040 104857599 31457280 83 Linux
Command (m for help): t
Partition number (1-3, default 3): 3
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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 label type: dos
Disk identifier: 0x0005ea5f
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
/dev/sda3 41943040 104857599 31457280 8e Linux LVM
STEP 5: Create a new physical disk on the newly created primary partition
First refresh the partition table. Otherwise pvcreate will complain that /dev/sda3 does not exist.
[root@test1 ~]# pvcreate /dev/sda3 Device /dev/sda3 not found (or ignored by filtering).
So call partprobe then try again.
[root@test1 ~]# partprobe
Create the new physical volume
[root@test1 ~]# pvcreate /dev/sda3 Physical volume "/dev/sda3" successfully created
STEP 6: Extend the volume group rhel over the new physical volume.
[root@test1 ~]# vgextend rhel /dev/sda3 Volume group "rhel" successfully extended [root@test1 ~]# vgs VG #PV #LV #SN Attr VSize VFree rhel 2 2 0 wz--n- 49.50g 30.04g [root@test1 ~]# pvs -o+pv_used PV VG Fmt Attr PSize PFree Used /dev/sda2 rhel lvm2 a-- 19.51g 40.00m 19.47g /dev/sda3 rhel lvm2 a-- 30.00g 30.00g 0
We see here we have now 30g free in this rhel volume group.
STEP 7: Resize the root logical volume to fill all the available space
[root@test1 ~]# lvresize -l +100%FREE /dev/mapper/rhel-root Size of logical volume rhel/root changed from 17.47 GiB (4472 extents) to 47.50 GiB (12161 extents). Logical volume root successfully resized. [root@test1 ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root rhel -wi-ao---- 47.50g swap rhel -wi-ao---- 2.00g
STEP 8: Extend the file system to fill the entire logical volume.
Note that by default RHEL7 uses xfs so we have to use xfs_growfs. For other partition types you can use resizefs
[root@test1 ~]# xfs_growfs /dev/mapper/rhel-root
meta-data=/dev/mapper/rhel-root isize=256 agcount=4, agsize=1144832 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=4579328, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 4579328 to 12452864
[root@test1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rhel-root 48G 4.0G 44G 9% /
devtmpfs 3.9G 0 3.9G 0% /dev
tmpfs 3.9G 152K 3.9G 1% /dev/shm
tmpfs 3.9G 8.8M 3.9G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda1 497M 212M 286M 43% /boot
tmpfs 783M 16K 783M 1% /run/user/1001