[SOLVED] Confused about VM Disk resize feature

Discuss
1

Hi Devs,

Sorry for asking this question, but I’m a bit confused as to the features with the beta version of OpenNebula 5.4. In the following document, it is stated that for vCenter VM disk resizing is possible:

http://docs.opennebula.org/5.4/intro_release_notes/release_notes/whats_new.html

But when you click on the link here:

http://docs.opennebula.org/5.4/operation/vm_management/vm_instances.html#vm-guide2-resize-disk

It states that “This is only available for Linux guests in KVM.”

So I’m confused, is this a typo or is the feature not available for vCenter and VMs in vSphere clusters?

Please elaborate.
Jesus

2

Don’t be sorry Jesus,
community’s comments are more than welcomed.

In 5.4, vCenter VM disks can be resized (increased) at boot time or when the VM is in poweroff and you resume the VM. The VM will see that its hard disks are bigger however it will be the responsability of the Guest OS to expand its filesystem to get the new space. So the documentation is still not updated ( I’d like to confirm if current vCenter contextualization packages support resize for both Linux and Windows).

Cheers!

3

Hi Miguel,

Thanks for the reply. Now that RC1 is out and I have upgraded to it, I see the following change in the docs:

http://docs.opennebula.org/5.4/operation/vm_management/vm_instances.html#vm-guide2-resize-disk

*Increase the size of the disk container prior to launching the VM.
*Using the contextualization packages, at boot time the VM will grow the filesystem to adjust to the new size. This is only available for Linux guests in KVM and vCenter.

I have built a brand new VM with minimal requirements in vcenter, configured it to all the necessary specs for a template, installed the latest contextualization rpm as well as the dracut-modules-growroot package (it’s a CentOS 6.9 template) and if I instantiate a machine with a bigger disk, the disk is grown, but the filesystem is not adjusted accordingly so I’m wondering what am I missing from the instructions to make this work in vCenter?

As an added note, I thought the issue was that I was using LVM as the partition manager, so I recreated a template with just an ext4 partition as the root partition and the partition and filesystem is not resized accordingly, only the physical disk is and fdisk sees the new size.

4

Can you check that the root partition is the latest one? growroot is only able to grow the last partition.

5

Hi Javi,

Thanks for the response. Yes the root partition is the last partition in the list. Below I have included all the relavent information for both types of systems which I have been able to instantiate, but fail to expand the disk according to the documentation.

LVM System (CentOS 6.8 x86_64)

Template Data

User template
DESCRIPTION = "expanddisklvm server"
HYPERVISOR = "vcenter"
LOGO = "images/logos/centos.png"
SIZE = "102400"
VCENTER_CCR_REF = "domain-c7"
VCENTER_INSTANCE_ID = "29b2c991-32bb-40b4-be9a-ab287a230cfc"
VCENTER_TEMPLATE_REF = "vm-610"

Template

AUTOMATIC_DS_REQUIREMENTS = "\"CLUSTERS/ID\" @> 100"
AUTOMATIC_REQUIREMENTS = "(CLUSTER_ID = 100) & !(PUBLIC_CLOUD = YES)"
CONTEXT = [
  DISK_ID = "1",
  DNS_HOSTNAME = "YES",
  ETH0_CONTEXT_FORCE_IPV4 = "",
  ETH0_DNS = "172.26.1.235 172.26.1.236",
  ETH0_GATEWAY = "172.20.64.1",
  ETH0_GATEWAY6 = "",
  ETH0_IP = "172.20.64.145",
  ETH0_IP6 = "",
  ETH0_IP6_PREFIX_LENGTH = "",
  ETH0_IP6_ULA = "",
  ETH0_MAC = "02:00:ac:14:40:91",
  ETH0_MASK = "255.255.254.0",
  ETH0_MTU = "",
  ETH0_NETWORK = "",
  ETH0_SEARCH_DOMAIN = "",
  ETH0_VLAN_ID = "",
  ETH0_VROUTER_IP = "",
  ETH0_VROUTER_IP6 = "",
  ETH0_VROUTER_MANAGEMENT = "",
  NETWORK = "YES",
  SET_HOSTNAME = "expanddisklvm01",
  SSH_PUBLIC_KEY = "ssh-rsa blah",
  TARGET = "hda" ]
CPU = "2"
DISK = [
  CLONE = "YES",
  CLONE_TARGET = "NONE",
  CLUSTER_ID = "100",
  DATASTORE = "[vcenter65 - -01] pure01_vm_datastore_1 - CLUSTER01 (IMG)",
  DATASTORE_ID = "100",
  DEV_PREFIX = "sd",
  DISK_ID = "0",
  DISK_SNAPSHOT_TOTAL_SIZE = "0",
  DISK_TYPE = "FILE",
  IMAGE = "centos68min_mergedisk_1 - pure01_vm_datastore_1",
  IMAGE_ID = "2",
  IMAGE_STATE = "2",
  IMAGE_UNAME = "oneadmin",
  LN_TARGET = "NONE",
  OPENNEBULA_MANAGED = "NO",
  ORIGINAL_SIZE = "40960",
  READONLY = "NO",
  SAVE = "NO",
  SIZE = "102400",
  SOURCE = "centos68min_mergedisk/centos68min_mergedisk_1.vmdk",
  TARGET = "sda",
  TM_MAD = "vcenter",
  TYPE = "FILE",
  VCENTER_DS_REF = "datastore-32",
  VCENTER_INSTANCE_ID = "29b2c991-32bb-40b4-be9a-ab287a230cfc" ]
GRAPHICS = [
  LISTEN = "0.0.0.0",
  PORT = "5918",
  TYPE = "vnc" ]
MEMORY = "4096"
NIC = [
  AR_ID = "0",
  BRIDGE = "VLAN_2064_172_20_64_0-23_SHAREB",
  CLUSTER_ID = "100",
  DNS = "172.26.1.235 172.26.1.236",
  GATEWAY = "172.20.64.1",
  IP = "172.20.64.145",
  MAC = "02:00:ac:14:40:91", 
  MODEL = "virtualvmxnet3",
  NETWORK = "[sjcvcenter65 - -01] VLAN_2064_172_20_64_0-23_SHAREB - CLUSTER01",
  NETWORK_ID = "1",
  NETWORK_MASK = "255.255.254.0",
  NETWORK_UNAME = "oneadmin",
  NIC_ID = "0",
  SEARCH_DOMAIN = "",
  SECURITY_GROUPS = "0",
  TARGET = "one-18-0",
  VCENTER_CCR_REF = "domain-c7",
  VCENTER_INSTANCE_ID = "29b2c991-32bb-40b4-be9a-ab287a230cfc",
  VCENTER_NET_REF = "dvportgroup-69",
  VCENTER_PORTGROUP_TYPE = "Distributed Port Group",
  VN_MAD = "dummy" ]
SECURITY_GROUP_RULE = [
  PROTOCOL = "ALL",
  RULE_TYPE = "OUTBOUND",
  SECURITY_GROUP_ID = "0",
  SECURITY_GROUP_NAME = "default" ]
SECURITY_GROUP_RULE = [
   PROTOCOL = "ALL",
   RULE_TYPE = "INBOUND",
  SECURITY_GROUP_ID = "0",
  SECURITY_GROUP_NAME = "default" ]
VCPU = "2" 
VMID = "18"

Login into system providess the following data:

[root@expanddisklvm01 ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       39G  1.1G   36G   3% /
tmpfs                 1.9G     0  1.9G   0% /dev/shm
/dev/sda1             477M   54M  398M  12% /boot

[root@expanddisklvm01 ~]# fdisk -luc

Disk /dev/sda: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders, total 209715200 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: 0x00088a3d

Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   209712509   104343231   8e  Linux LVM

Disk /dev/mapper/VolGroup-lv_root: 42.4 GB, 42421190656 bytes
255 heads, 63 sectors/track, 5157 cylinders, total 82853888 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: 0x00000000

[root@expanddisklvm01 ~]# yum install dracut-modules-growroot
Loaded plugins: fastestmirror
Setting up Install Process
Determining fastest mirrors
epel/metalink                                                                                                                                                                                                                       |  13 kB     00:00     
 * base: mirror.keystealth.org
 * epel: mirror.sjc02.svwh.net
 * extras: centos.host-engine.com
 * updates: mirrors.sonic.net
base                                                                                                                                                                                                                                | 3.7 kB     00:00     
epel                                                                                                                                                                                                                                | 4.3 kB     00:00     
epel/primary_db                                                                                                                                                                                                                     | 5.9 MB     00:00     
extras                                                                                                                                                                                                                              | 3.4 kB     00:00     
updates                                                                                                                                                                                                                             | 3.4 kB     00:00     
updates/primary_db                                                                                                                                                                                                                  | 2.5 MB     00:00     
Package dracut-modules-growroot-0.20-2.el6.noarch already installed and latest version
Nothing to do
[root@expanddisklvm01 one-context]# rpm -qa | grep context
one-context-5.3.80-1.el6.noarch
[root@expanddisklvm01 one-context]#

Regular Partition System (CentOS 6.9 x86_64)

Template Data

User template

DESCRIPTION = "expanddisk server"
HYPERVISOR = "vcenter"
LOGO = "images/logos/centos.png"
VCENTER_CCR_REF = "domain-c7"
VCENTER_TEMPLATE_REF = "vm-1041"
VM_TEMPLATE = "29b2c991-32bb-40b4-be9a-ab287a230cfc"

Template

AUTOMATIC_DS_REQUIREMENTS = "\"CLUSTERS/ID\" @> 100"
AUTOMATIC_REQUIREMENTS = "(CLUSTER_ID = 100) & !(PUBLIC_CLOUD = YES)"
CONTEXT = [
  DISK_ID = "1",
  DNS_HOSTNAME = "YES",
  ETH0_CONTEXT_FORCE_IPV4 = "",
  ETH0_DNS = "172.26.1.235 172.26.1.236",
  ETH0_GATEWAY = "172.20.64.1",
  ETH0_GATEWAY6 = "",
  ETH0_IP = "172.20.64.144",
  ETH0_IP6 = "",
  ETH0_IP6_PREFIX_LENGTH = "",
  ETH0_IP6_ULA = "",
  ETH0_MAC = "02:00:ac:14:40:90",
  ETH0_MASK = "255.255.254.0",
  ETH0_MTU = "",
  ETH0_NETWORK = "",
  ETH0_SEARCH_DOMAIN = "",
  ETH0_VLAN_ID = "",
  ETH0_VROUTER_IP = "",
  ETH0_VROUTER_IP6 = "",
  ETH0_VROUTER_MANAGEMENT = "",
  NETWORK = "YES",
  SET_HOSTNAME = "expanddisk01.",
  SSH_PUBLIC_KEY = "ssh-rsa blah",
  TARGET = "hda" ]
CPU = "2"
DISK = [
  ALLOW_ORPHANS = "NO",
  CLONE = "YES",
  CLONE_TARGET = "SYSTEM",
  CLUSTER_ID = "100",
  DATASTORE = "pure01_vm_datastore_3 [vcenter65. - -01] (IMG)",
  DATASTORE_ID = "106",
  DEV_PREFIX = "sd",
  DISK_ID = "0",
  DISK_SNAPSHOT_TOTAL_SIZE = "0",
  DISK_TYPE = "FILE",
  IMAGE = "centos69min_oneext4 - pure01_vm_datastore_3 [Template 7]",
  IMAGE_ID = "4",
  IMAGE_STATE = "2",
  LN_TARGET = "NONE",
  OPENNEBULA_MANAGED = "NO",
  ORIGINAL_SIZE = "16384",
  READONLY = "NO",
  SAVE = "NO",
  SIZE = "102400",
  SOURCE = "centos69min_oneext4/centos69min_oneext4.vmdk",
  TARGET = "sda",
  TM_MAD = "vcenter",
  TYPE = "FILE",
  VCENTER_DS_REF = "datastore-517",
  VCENTER_INSTANCE_ID = "29b2c991-32bb-40b4-be9a-ab287a230cfc" ]
GRAPHICS = [
  LISTEN = "0.0.0.0",
  PORT = "5916",
  TYPE = "vnc" ]
MEMORY = "4096"
NIC = [
  AR_ID = "0",
  BRIDGE = "VLAN_2064_172_20_64_0-23_SHAREB",
  CLUSTER_ID = "100",
  DNS = "172.26.1.235 172.26.1.236",
  GATEWAY = "172.20.64.1",
  IP = "172.20.64.144",
  MAC = "02:00:ac:14:40:90",
  MODEL = "virtualvmxnet3",
  NETWORK = "[vcenter65. - -01] VLAN_2064_172_20_64_0-23_SHAREB - CLUSTER01",
  NETWORK_ID = "1",
  NETWORK_MASK = "255.255.254.0",
  NETWORK_UNAME = "oneadmin",
  NIC_ID = "0",
  SEARCH_DOMAIN = "",
  SECURITY_GROUPS = "0",
  TARGET = "one-16-0",
  VCENTER_CCR_REF = "domain-c7",
  VCENTER_INSTANCE_ID = "29b2c991-32bb-40b4-be9a-ab287a230cfc",
  VCENTER_NET_REF = "dvportgroup-69",
  VCENTER_PORTGROUP_TYPE = "Distributed Port Group",
  VN_MAD = "dummy" ]
SECURITY_GROUP_RULE = [
  PROTOCOL = "ALL",
  RULE_TYPE = "OUTBOUND",
  SECURITY_GROUP_ID = "0",
  SECURITY_GROUP_NAME = "default" ]
SECURITY_GROUP_RULE = [
  PROTOCOL = "ALL",
  RULE_TYPE = "INBOUND",
  SECURITY_GROUP_ID = "0",
  SECURITY_GROUP_NAME = "default" ]
VCPU = "2"
VMID = "16"

Login into system provides the following data:

[root@expanddisk01 ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda2        16G  1.1G   14G   8% /
tmpfs           1.9G     0  1.9G   0% /dev/shm
/dev/sda1       477M   52M  400M  12% /boot
[root@expanddisk01 ~]# fdisk -luc

Disk /dev/sda: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders, total 209715200 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: 0x000918ed

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   209712509   104343231   83  Linux
[root@expanddisk01 ~]# yum install dracut-modules-growroot
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
epel/metalink                                                                                                                                                                                                                       |  13 kB     00:00     
 * base: mirror.linuxfix.com
 * epel: mirror.sfo12.us.leaseweb.net
 * extras: centos-distro.cavecreek.net
 * updates: mirrors.kernel.org
base                                                                                                                                                                                                                                | 3.7 kB     00:00     
epel                                                                                                                                                                                                                                | 4.3 kB     00:00     
epel/primary_db                                                                                                                                                                                                                     | 5.9 MB     00:00     
extras                                                                                                                                                                                                                              | 3.4 kB     00:00     
updates                                                                                                                                                                                                                             | 3.4 kB     00:00     
Package dracut-modules-growroot-0.20-2.el6.noarch already installed and latest version
Nothing to do
[root@expanddisk01 ~]# rpm -qa | grep context
one-context-5.3.80-1.el6.noarch
[root@expanddisk01 ~]#

Hopefully this provides sufficient information about this problem. If not let me know what additional information you wouild like me to provide.

Thanks,
Jesus

6

It seems the new contextualization packages have solved the expanding partition issue I was running into. Just wanted to point that out in case someone else runs into the same issue in the future.

1 Like
7

An additional caveat for those wondering in case you see that your filesystem has not expanded.

  1. If you are not using LVM, just straight partitioning, your disk will expand on first boot.
  2. If you are using LVM, your disk will expand on the next reboot.

I have not tried other partitioning types.

Hope this helps.

1 Like
8

Thanks!

I have noticed that the disk of my VM (using LVM) on resize does change immediately, but not the partition itself…
I’m still running some tests (maybe contextualization package issue?), and will share if I get anything.