ESXi Notes

Having previously worked with Oracle VirtualBox I thought this this would be an easy transition – but no way.

ESXi feel much more like a enterprise ready product, with complexities at that level as well.

Most of the things in here will be related to the CLI interface of ESXi version 6.5.

It is work in progress so there will be errors and things I have misunderstood below as it is for my own use.

Storage

Storage is provisioned in 3 layers starting from lowest level:

  1. Physical Disks (or raid/nas/san drives)
  2. Datastores: collection of physical disks making a logical disk
  3. Virtual Disks: VM storage placed in datastores as vmdk files

Simplified diagram:

image

Physical Disks (devices)

Physical disks are located in directory:

/vmfs/devices/disks

Physical hard disks maps to files in /vmfs/devices/disks like this:

t10.SanDisk00Ultra_Fit000000000000004C531001491102119083

Partitions maps to the above filename but ending with “:” and number like this:

t10.SanDisk00Ultra_Fit000000000000004C531001491102119083:1

Listing disks only:

ls -lh /vmfs/devices/disks | grep -v ":[0-9]$" | grep -v "vml\." | grep -v "total"

Datastores

Datastores are located in directory:

/vmfs/volumes

Datastores are having names like this:

587949b5-46baef34-fb63-1866da2041ef

When a datastore is created and names then it gets a link from the name to the file above like:

SSD -> 587949b5-46baef34-fb63-1866da2041ef

Within the datastore you will find the virtual disks.

Virtual Disks

Virtual disks are located in directory:

/vmfs/volumes/{datastorename}/{vmname}

Together with other VM related files.

Main virtual disk names:

  • {diskname}.vmdk: disk configuration file
  • {diskname}-flat.vmdk: thin provisioned file (full file)
  • {diskname}-rdmp.vmdk: raw provisioned file (link only)

Raw Device Mapping (RDM)

A physical disk can be mapped directly to a VM by creating a link.

Use this command:

vmkfstools -z /vmfs/devices/disks/{physical disk} /vmfs/volumes/SSD/{vmname}/{vmdkname}.vmdk

For example:

vmkfstools -z /vmfs/devices/disks/t10.SanDisk00Ultra_Fit000000000000004C531001491102119083 /vmfs/volumes/SSD/windows/hdd1.vmdk

Creates the following files:

  • {diskname}.vmdk: disk configuration file
  • {diskname}-rdmp.vmdk: raw provisioned file (link only)

Equally to remove the links to a VM do the following:

rm /vmfs/volumes/SSD/windows/hdd1.vmdk
rm /vmfs/volumes/SSD/windows/hdd1-rdmp.vmdk

Virtual Disk Backup

It is easy to do a “cold” backup when the VM is shut down.

Using the command to clone the original disk:

vmkfstools –i /vmfs/volumes/{datastorename}/{vmname}/{vmdkname}.vmdk {backupdest}/{vmdkname}.vmdk -d thin

This command should only be used with thin provisioned disks.

VM Upgrade

When importing a VM from other sources you will find the VM version is older.

I had this problem where I got a warning about the Linux version was not correct.

I could only pick Debian 6 where I was using Debian 8.

This is caused by the VM version is older.

To upgrade the VM version run the following command:

vim-cmd vmsvc/upgrade {vmid} vmx-13

The {vmid} can be obtained by running this command:

vim-cmd vmsvc/getallvms

Extending Virtual Disk

Well you don’t really extend but add another one instead.

Click on the VM details:

image

Click Add hard disk – New hard disk:

image

Adjust disk size:

image

Reboot the VM

List the disk:

# lsblk

NAME               MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                  8:0    0  100G  0 disk
|-sda1               8:1    0  428M  0 part /boot
|-sda2               8:2    0 18.2G  0 part
| |-turnkey-root   254:0    0   99G  0 lvm  /
| `-turnkey-swap_1 254:1    0  512M  0 lvm  [SWAP]
`-sda3               8:3    0 81.4G  0 part
  `-turnkey-root   254:0    0   99G  0 lvm  /
sdb                  8:16   0  100G  0 disk

So new hard disk is: sdb

Initialise the physical volume:

# pvcreate /dev/sdb
  Physical volume "/dev/sdb" successfully created

Extend volume group in LVM:

# vgextend turnkey /dev/sdb
  Volume group "turnkey" successfully extended

Extend size of logical volume – first try failed as slightly less than 100GB available so just use extents option instead:

# lvextend -L+100G /dev/turnkey/root
  Insufficient free space: 25600 extents needed, but only 25599 available
# lvextend -l 25599 /dev/turnkey/root
  Size of logical volume turnkey/root changed from 99.02 GiB (25348 extents) to 100.00 GiB (25599 extents).
  Logical volume root successfully resized

Resize the file system:

# resize2fs /dev/turnkey/root
resize2fs 1.42.12 (29-Aug-2014)
Filesystem at /dev/turnkey/root is mounted on /; on-line resizing required
old_desc_blocks = 7, new_desc_blocks = 7
The filesystem on /dev/turnkey/root is now 26213376 (4k) blocks long.

All done:

# lsblk
NAME               MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                  8:0    0  100G  0 disk
|-sda1               8:1    0  428M  0 part /boot
|-sda2               8:2    0 18.2G  0 part
| |-turnkey-root   254:0    0  100G  0 lvm  /
| `-turnkey-swap_1 254:1    0  512M  0 lvm  [SWAP]
`-sda3               8:3    0 81.4G  0 part
  `-turnkey-root   254:0    0  100G  0 lvm  /
sdb                  8:16   0  100G  0 disk
`-turnkey-root     254:0    0  100G  0 lvm  /

This entry was written by Kent Willumsen , posted on Wednesday April 05 2017at 06:04 pm , filed under Server, Technical Knowledge and tagged . Bookmark the permalink . Post a comment below or leave a trackback: Trackback URL.

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