The following slides were part of a company meeting where I was giving a VMware 101 lesson for our engineers who work outside of data center technologies. It's a high level overview.

1. VSPHERE 101
PAUL WOODWARD – SYSTEMS ENGINEER

2. INTRODUCTION • Paul Woodward Jr
• Twitter @ExploreVM
• Blog: ExploreVM.com
• ExploreVM Podcast – iTunes, Google Play, I
Heart Radio, etc..
• Virtual Design Master Season 4 – 3rd
Place
• Tech Field Day 15 Delegate (Sept. 2017)
• Spoken at 8 VMUG meetings across 3
states
• Speaking at Nutanix .Next 2017

3. OVERVIEW
• Introduction to VMware vSphere
• Snapshots
• Basic vSphere Troubleshooting
• Q&A

4. VMWARE PRODUCT SUITE
• ESXi - Hypervisor
• vSphere Client – Web (Flash & HTML5) Based or Windows #C “fat” client
• vCenter Server – Centralized management of the ESXi environment
• Workstation & Fusion – Virtualized offering for PC & MAC
• Site Recovery Manager – Automated site to site replication
• NSX – VMware virtualized networking offering
• vSAN – VMware virtualized storage offering
• AirWatch – Mobile device management
• Horizon – Virtual Desktop Infrastructure (VDI) platform
• vRealize Suite:
• Log Insight
• Operations Manager
• Automation
• Network Insight
• Orchestrator

5. WHAT IS ESXI & HOW DOES IT WORK?

6. TRIVIA:
WHAT DOES ESX STAND FOR?
ELASTIC SKY X

7. WHAT IS ESXI?
• Type-1 Hypervisor (bare
metal)
• Not an operating system
• VMkernel is the core of ESXi
• Microkernel offering the
minimum software
connectivity between the
hardware and the guest OS
• CPU & Memory is handled
directly by the VMkernel
• Other hardware is handled by
the vmklinux module

8. COMMON TASKS IN VMWARE
• vMotion – Live migration
• svMotion – Storage vMotion
• Clone
• Full Clone – separate from
parent VM
• Linked Clone – shares virtual
disks
• Snapshots
*Most advanced tasks require vCenter
Server
• Create New VM
• Edit VM Settings
• Can be done as a hot add
• Start/Stop VM
• Browse Datastore
• Configure Virtual Networking

9. WHAT IS A VIRTUAL MACHINE?
• A virtual machine is a collection of files that create the server
emulation
• These files include:
• VMX file – Configuration
• VMXF file – Supplementational Configuration
• VMDK Files – Disk related files, includes .VMDK, -delta.vmdk, -
rdm.vmds
• VSWP File – Memory overflow (SWAP) file
• VMSD File – Snapshot details
• VMSS File – Memory contents of suspended VM
• VMSN File – Snapshot Files
• NVRAM File – BIOS file
• Log files

10. SNAPSHOTS: THE SILENT KILLER

11. SNAPSHOTS – THE MORE YOU KNOW
WHAT ARE SNAPSHOTS?
• Point in Time preservation of
a VM’s Data and State
• All of the files that make up
the VM:
• Disks
• Memory
• Devices
WHAT SNAPSHOT ARE NOT
• Snapshots are NOT Backups
• Snapshots are NOT Backups
• Snapshots are NOT Backups

12. HOW SNAPSHOTS WORK
1. A request to create, remove, or revert a snapshot for a virtual machine is sent from
the client to the server using the VMware API.
2. The request is forwarded to the VMware ESX host that is currently hosting the virtual
machine that has issue.
3. If the snapshot includes the memory option, the ESX host writes the memory of the
virtual machine to disk
4. If the snapshot includes the quiesce option, the ESX host requests the guest
operating system to quiesce the disks via VMware Tool
5. The ESX host makes the appropriate changes to the virtual machine's snapshot
database (.vmsd file) and the changes are reflected in the Snapshot Manager of the
virtual machine.
6. The ESX host calls a function similar to the Virtual Disk API functions to make
changes to the child disks (-delta.vmdk and .vmdk files) and the disk chain.

13. THE CHILD DISK
• Child Disk is a Sparse Disk
• Copy on Write
• If a VM is running off a snapshot, it is running off the child disk
• Child Disks can fill a datastore
• I/O is impacted by the existence of a Child Disk

14. THE DISK CHAIN

15. DELETE, GO TO, OR CONSOLIDATE
SNAPSHOTS

16. DELETE, GO TO, OR CONSOLIDATE
SNAPSHOTS
• Delete - Use the Delete option to remove a single parent or child snapshot from the
snapshot tree. Delete writes disk changes between the snapshot and the previous
delta disk state to the parent snapshot.
• You can also use the Delete option to remove a corrupt snapshot and its files
from an abandoned branch of the snapshot tree without merging them with the
parent snapshot.
• Delete All - Use the Delete All option to delete all snapshots from the Snapshot
Manager. Delete all consolidates and writes changes between snapshots and
previous delta disk states to the base parent disk and merges them with the base
virtual machine disk.

17. THE TROUBLE WITH “DELETE ALL”
Scenario: 3 snapshots on the VM (graphic from the disk chain slide)
Snapshot 1 – 20GB
Snapshot 2 – 10GB
Snapshot 3 – 30GB
• When you choose “delete all” the following will happen:
• Snapshot 2 will grow to 40GB at most
• Snapshot 1 will grow to 60GB at most
• Snapshot 1 will be committed to the original VMDK
• All snapshot files are deleted
• In other words: Snapshot 3 is merged into Snapshot 2, Snapshot 2 is
merged into Snapshot 1, Snapshot 1 is merged into the original
flat.vmdk and afterwards all snapshot files are deleted.

18. REVERT & GO TO
Revert to Current Snapshot
• Restores the parent snapshot, one level up in the hierarchy from the You
are Here position. Revert to Current Snapshot activates the parent
snapshot of the current state of the virtual machine.
Go To
• Lets you restore any snapshot in the snapshot tree and makes that
snapshot the parent snapshot of the current state of the virtual machine.
Subsequent snapshots from this point create a new branch of the
snapshot tree.
Restoring snapshots has the following effects:
• The current disk and memory states are discarded, and the virtual
machine reverts to the disk and memory states of the parent snapshot.
• Existing snapshots are not removed. You can restore those snapshots at
any time
• If the snapshot includes the memory state, the virtual machine will be in

19. PHANTOM OF THE
SNAPSHOTS
Phantom Snapshots
• Snapshots that do not appear in
snapshot manager
• Can degrade performance
• Can be identified by rogue .VMDK or
.delta.VMDK files
• Quick resolution – Create a new snapshot
and delete all snapshots
• If issue persists, escalate to VMware SME

20. SNAPSHOT BEST PRACTICES
• Do Not Use Snapshots as Backups
• Delete Snapshots ASAP – No longer than 3 days
• Only chain 2-3 snapshots together
• Clear snapshots before:
• Increasing virtual machine disk size

21. SNAPSHOT TRIVIA!
• Q: What is the maximum recommended time before deleting a
snapshot?
• A: 3 Days (72 hours)

22. BASIC TROUBLESHOOTING TECHNIQUES

23. STEP 1 – BLAME THE NETWORK AND WALK
AWAY

24. VCENTER/HOST ALARMS
• Triggered alarms are viewed on the summary page of the Datacenter, Host, VM, or
under the Alarms tab.
• Alarms are found under Monitor -> Issues -> Triggered Alarms in the web client
• Excellent place to start for troubleshooting issues; many KBs and blogs out there on
resolutions

25. HOST HARDWARE STATUS
• Moved to web client with 6.0
• Select the host -> click Monitor -> Hardware Status
• Not always accurate, check within host’s out of band management as well if
hardware issue is suspected

26. VIRTUAL MACHINE & HOST PERFORMANCE
ISSUES
If the VM performs poorly or won’t
boot:
• Verify the host is not overloaded
• Verify storage is still available to
the host
• Verify the Datastore is not full
• Adequate resources allocated to the
VM?
• Verify networking
• Host performance issues are
usually tied to being overpopulated,
or a single VM consuming
significant amounts of resources
• Free up space on the host through
vMotion or, if necessary, shut down
excess VMs to regain control
• If unable to connect to the host, or
if vCenter Server loses connection
to host: Restart Management
Agents

27. ESXI DCUI

28. ESXI SSH
Enable ESXi SSH
• Select host -> Manage -> Settings ->Security Profile ->
Highlight SSH ->Edit Restart Management Agents
• /etc/init.d/hostd restart
• /etc/init.d/vpxa restart
Export System Logs
ssh root@ESXHostnameOrIPAddress 'vm-
support -s >
/vmfs/volumes/datastorexxx/vm-
support-Hostname.tgz‘

29. OPENING A TICKET WITH VMWARE
• U.S. / Headquarters
• 877 486 9273 - Support
• 650 475 5345 – Local
• Target Response Times
• Critical (Severity 1) - 30 minutes or less: 24x7
• Major (Severity 2) - 4 business hours
• Minor (Severity 3) - 8 business hours
• Cosmetic (Severity 4) - 8 business hours
• Pull logs and submit with ticket
• Detail all troubleshooting performed in detail to save time
• Typically GSS will work on the issue for 1 hour then escalate

30. TROUBLESHOOTING TRIVIA!
• Q: How do you regain access to a host if it’s lost contact to
vCenter or the vSphere client?
• A: Restart Management Services

31. RECOMMENDATIONS FOR CLIENTS
vRealize Log Insight
• Centralized log management
• Included with vCenter license
• 25 OSI licenses included with
vCenter
vCheck Reports
• PowerShell HTML framework
script
• Community driven and open
source
• 160+ reporting metrics
• Can be scheduled & output to
email

32. ANY QUESTIONS
All links & slide deck will be on www.ExploreVM.com