What’s new in vSphere 6.5 and a lot of things vSphere I wasn’t aware

I had the chance to attend vSphere 6.5 ICM training at VMware office in Bangalore recently. My last ICM was 5 or 5.1 some years ago. The world does not need another “what’s new in vSphere 6.5” post. I took some notes during the training and I thought I would dump it here anyway.

1.VCSA 6.5 is based on Photon OS and not SLES as before. Photon OS began its life as VMware’s customized for container Linux distro that does not depend directly on any other distro.

2.vSphere Update Manager (VUM) is now apart of VCSA 6.5. Before 6.5, you have to run it on Windows.

3.Dump Collector is also apart of VCSA (not sure from which version).

4.VCSA 6.5 has a management portal which can be accessed at VCSA_IP:5480. You can create a backup from here and restore from it using the installer.

5.You can still use service-control to manage vCenter services from the command. From 6.5, you can also manage vCenter Services from the Web client.

6.Speaking of Web Client, there are two web clients. The old vSphere Web Client (Flash/Flex client) and the new vSphere Client (HTML 5).

7.The legacy C# client is not available for 6.5

8.During the training, I used the HTML 5 client as much as possible. It has limited functionality right now. I found the following not working:

You cannot increase datastore
It is hard coded to create VMFS5 type data store only
You cannot create NFS datastore
You can do host migration only

The full set of features available in the HTML 5 client:

9.There is a new version of VMFS, VMFS 6. ESXi 6.5 can create VMFS 5 and 6. VMFS6 supports 1 MB and 512 MB block sizes.

10.In addition to LSI Logic SAS, BusLogic, PVSCSI and AHCI SATA, ESXi 6.5 has virtual NVMe storage controller for virtual machine.

11.Support for 32 Gbps HBA in ESXi 6.5

12.VCSA 6.5 has native HA – Enabling it deploys in passive mode and quorom appliance

13.DRS evenly distributes VMs

I was not aware of the following:

1.vpxa is baked into ESXi

2.SRM can use vSphere Replication.

3.VIB = vSphere Infrastructure Bundle.

4.Enhenced Linked mode since vSphere 6.0

5.e1000e virtual NIC since vSphere 5.0 with HW version 8.

6.Enhenced Linked mode since 6.0

7.iSCSI HBA- The configuration is done from the HBA BIOS.

8.ToE NIC- The configuration is done from vSphere client.

9.Starting with vSphere 6.0, there are two Lockdown Modes – Normal and Strict. (KB 1008077)


vmkvsitools in ESXi

There is very little I can find about vmkvsitools on the internet. VMware document says “vmkvsitools is intended for use with VMware Technical Support. Do not use vmkvsitools to manage your system.”. But we normally don’t care as long as we know what we are doing, do we?

The following commands are available under vmkvsitools in ESXi 6.0 U1.

    usage: vmkvsitools [options] [function] [arguments]
           or [function] [arguments]

       --cache, -c    Perform the operation on a given VSI cache file


You can run them using “vmkvsitools function”. For example-

vmkvsitools hwclock
04:26:29   07/17/2017   UTC 

You can also run them directly by typing just the command as they are symblinked from /bin.

    ls -l /bin |  grep vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 amldump -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 bootOption -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 hwclock -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 irqinfo -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 lsof -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 lspci -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 pgrep -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 pidof -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 pkill -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 ps -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 uptime -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 vdf -> /bin/vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 vdu -> /bin/vmkvsitools
    -r-xr-xr-x    1 root     root         75868 Sep 16  2015 vmkvsitools
    lrwxrwxrwx    1 root     root            16 Sep 16  2015 vmware -> /bin/vmkvsitools

VMFS does not stripe across LUNs or extents

Note that the VMFS does not stripe across LUNs when more
than one LUN is allocated to a given VMFS volume.

VMFS Best Practices Guide

The hosts try to put distance between themselves on the datastore to reduce any contention for resources, but they still try to keep the objects that they manage close together.

VMFS Extents – Are they bad, or simply misunderstood?

ESXi partition layout

The following partitions are created on the boot disk of ESXi.

Size Purpose
4.2 MB Boot
250 MB Boot Bank
250 MB Alternate Boot Bank
110 MB Coredump. Not used since ESXi 5.5. It exists for backward compatibility
2.5 GB Coredump. Introduced in ESXi 5.5, required for hosts with huge RAM
286 MB Store. Used for storing VMware tools etc..
4 GB Scratch. Persistent storage for log files, not created on USB and SD card installation
Remaining Space VMFS, local datastore. Not created on USB and SD card installation

Get partition table of the disk where ESXi is installed:

esxcli storage core device partition list
partedUtil getptbl /vmfs/devices/disks/ESXi_install_disk

The size of a partition is (End Sector – Start Secore) * 512 bytes.

Check active coredump partition:

esxcli system coredump partition list

Get a list of mounted filesystems. The boot partition and coredump partitions will not be mounted.