ESXi – Page 114

Home Labs made easier with VSAN 6.0 + USB Disks

03.04.2015 by William Lam // 23 Comments

VSAN 6.0 includes a large number of new enhancements and capabilities that I am sure many of you are excited to try out in your lab. One of the challenges with running VSAN in a home lab environment (non-Nested ESXi) is trying to find a platform that is both functional and cost effective. Some of the most popular platforms that I have seen customers use for running VSAN in their home labs are the Intel NUC and the Apple Mac Mini. Putting aside the memory constraints in these platforms, the number of internal disk slots for a disk drive is usually limited to two. This would give you just enough to meet the minimal requirement for VSAN by having at least a single SSD and MD.

If you wanted to scale up and add additional drives for either capacity purposes or testing out a new configurations, you are pretty much out of luck, right? Well, not necessary. During the development of VSAN 6.0, I came across a cool little nugget from one of the VSAN Engineers where USB-based disks could be claimed by VSAN which could be quite helpful for testing in a lab environment, especially using the hardware platforms that I mentioned earlier.

For a VSAN home lab, using cheap consumer USB-based disks which you can purchase several TB's for less than a hundred dollars or so and along with USB 3.0 connectivity is a pretty cost effective way to enhance hardware platforms like the Apple Mac Mini and Intel NUCs.

Disclaimer: This is not officially supported by VMware and should not be used in Production or evaluation of VSAN, especially when it comes to performance or expected behavior as this is now how the product works. Please use supported hardware found on the VMware VSAN HCL for official testing or evaluations.

Below are the instructions on how to enable USB-based disks to be claimable by VSAN.

Step 1 - Disable the USB Arbitrator service so that USB devices can been seen by the ESXi host by running the following two commands in the ESXi Shell:

/etc/init.d/usbarbitrator stop
chkconfig usbarbitrator off

Step 2 - Enable the following ESXi Advanced Setting (/VSAN/AllowUsbDisks) to allow USB disks to be claimed by VSAN by running the following command in the ESXi Shell:

esxcli system settings advanced set -o /VSAN/AllowUsbDisks -i 1

Step 3 - Connect your USB-based disks to your ESXi host (this can actually be done prior) and you can verify that they are seen by running the following command in the ESXi Shell:

vdq -q

Step 4 - If you are bootstrapping vCenter Server onto the VSAN Datastore, then you can create a VSAN Cluster by running "esxcli vsan cluster new" and then contribute the storage by adding the SSD device and the respective USB-based disks using the information from the previous step in the ESXi Shell:

esxcli vsan storage add -s t10.ATA_____Corsair_Force_GT________________________12136500000013420576 -d mpx.vmhba32:C0:T0:L0 -d mpx.vmhba33:C0:T0:L0 -d mpx.vmhba34:C0:T0:L0 -d mpx.vmhba40:C0:T0:L0

If we take a look a the VSAN configurations in the vSphere Web Client, we can see that we now have 4 USB-based disks contributing storage to the VSAN Disk Group. In this particular configuration, I was using my Mac Mini which has 4 x USB 3.0 devices that are connected and providing the "MD" disks and one of the internal drives that has an SSD. Ideally, you would probably want to boot ESXi from a USB device and then claim one of the internal drives along with 3 other USB devices for the most optimal configuration.

As a bonus, there is one other nugget that I discovered while testing out the USB-based disks for VSAN 6.0 which is another hidden option to support iSCSI based disks with VSAN. You will need to enable the option called /VSAN/AllowISCSIDisks using the same method as enabling USB-based disk option. This is not something I have personally tested, so YMMV but I suspect it will allow VSAN to claim an iSCSI device that has been connected to an ESXi host and allow it to contribute to a VSAN Disk Group as another way of providing additional capacity to VSAN with platforms that have restricted number of disk slots. Remember, neither of these solutions should be used beyond home labs and they are not officially supported by VMware, so do not bother trying to do anything fancy or running performance tests, you are just going to let your self down and not see the full potential of VSAN 🙂

New VOBs for creating vCenter Server alarms in vSphere 6.0

03.02.2015 by William Lam // Leave a Comment

Here are some new VOBs in vSphere 6.0 that I recently came across which can be useful on getting notified on specific events such failed login attempts in ESXi or detecting a device has gone offline in VSAN as some examples. These VOBs can be used to create vCenter Server alarms to take various actions such as a simple UI notification in the vSphere Web/C# Client to sending an email or SNMP trap regarding the event. For more information on how create vCenter Server alarms using VOBs, please take a look at these two articles here and here which also includes a comprehensive list of past vSphere VOBs in vSphere 5.5 which are still applicable in vSphere 6.0.

General vSphere 6.0 VOBs

VOB ID	VOB Description
esx.audit.account.locked	Remote access for an ESXi local user account has been locked temporarilly due to multiple failed login attempts.
esx.audit.account.loginfailures	Multiple remote login failures detected for an ESXi local user account.
esx.audit.esxcli.host.restart	Rebooting host through esxcli
esx.audit.lockdownmode.exceptions.changed	List of lockdown exception users has been changed.
esx.problem.coredump.copyspace	The free space available in default coredump copy location is insufficient to copy new coredumps.
esx.problem.coredump.extraction.failed.nospace	The given partition has insufficient amount of free space to extract the coredump.
esx.problem.dhclient.lease.offered.error	No expiry time on offered DHCP lease.
esx.problem.pageretire.selectedbutnotretired.high	Number of host physical memory pages that have been selected for retirement but could not yet be retired is high.
esx.problem.swap.systemSwap.isPDL.cannot.remove	System swap at path {1} was affected by the PDL of its datastore and was removed. System swap has been reconfigured.
esx.problem.swap.systemSwap.isPDL.removed.reconfig.failure	System swap at path {1} was affected by the PDL of its datastore. It was removed but the subsequent reconfiguration failed.
esx.problem.vmfs.ats.incompatibility.detected	Multi-extent ATS-only VMFS Volume unable to use ATS
esx.problem.vmfs.lockmode.inconsistency.detected	Inconsistent VMFS lockmode detected.
esx.problem.vmfs.spanned.lockmode.inconsistency.detected	Inconsistent VMFS lockmode detected on spanned volume.
esx.problem.vmfs.spanstate.incompatibility.detected	Incompatible VMFS span state detected.
esx.vFlash.VFlashResourceCapacityExtendedEvent	vFlash resource capacity is extended
vprob.vmfs.heartbeat.corruptondisk	VMFS Heartbeat Corruption Detected

VSAN 6.0 VOBs

VOB ID	VOB Description
esx.audit.vsan.net.vnic.added	Virtual SAN virtual NIC has been added.
esx.audit.vsan.net.vnic.deleted	Virtual SAN network configuration has been removed.
esx.problem.vob.vsan.dom.lsefixed	Virtual SAN detected and fixed a medium error on disk.
esx.problem.vob.vsan.dom.nospaceduringresync	Resync encountered no space error
esx.problem.vob.vsan.lsom.disklimit2	Failed to add disk to disk group.
esx.problem.vsan.dom.init.failed.status	Virtual SAN Distributed Object Manager failed to initialize
vprob.vob.vsan.pdl.offline	Virtual SAN device has gone offline.

Easily manage ESXi & VCSA SSH login banner & MOTD in vSphere 6.0

02.27.2015 by William Lam // 3 Comments

For customers who have a requirement to configure an SSH login banner and/or message of the day (MOTD) for ESXi or vCenter Server, this usually meant manually editing the /etc/issues (login banner) and /etc/motd (MOTD) configuration files. In vSphere 6.0, this has now been simplified by providing vSphere APIs to allow administrators to easily view and configure SSH login banner and MOTD for both ESXi and VCSA (this does not apply to vCenter Server for Windows).

For ESXi, there are two new ESXi Advanced properties called Config.Etc.issue and Config.Etc.motd and this can also be viewed and edited using the vSphere Web/C# Client as seen in the screenshot below:

For vCenter Server, there are also two new Advanced Options called etc.issue and etc.motd which can also be viewed and edited using the vSphere Web/C# Client as seen in the screenshot below:

What's Displayed

The /etc/issues displays a banner during an SSH login session, this means that you will see the message during the login as highlighted in the screenshot below:

The /etc/motd displays a banner after a successful SSH login as highlighted in the screenshot below:

How to Automate

You can use both the vSphere API/CLI to modify the issues and motd configurations. In the examples below, I will be using PowerCLI to demonstrate retrieving and setting the two properties.

Retrieve /etc/issues for VCSA

Get-AdvancedSetting -Entity $vc -Name "etc.issue" | Format-List

Set /etc/issues for VCSA

$msg = "
beware
you
are
entering
the
house
of
Cormac
the
grey
"
Get-AdvancedSetting -Entity $vc -Name "etc.issue" | Set-AdvancedSetting -Value $msg

Retrieve /etc/motd for VCSA

Get-AdvancedSetting -Entity $vc -Name "etc.motd" | Format-List

Set /etc/motd for VCSA

Get-AdvancedSetting -Entity $vc -Name "etc.motd" | Set-AdvancedSetting -Value $msg

Retrieve /etc/issues for ESXi

Get-VmHostAdvancedConfiguration -Name "Config.Etc.issue"

Set /etc/issues for ESXi

$msg = "
beware
you
are
entering
the
house
of
Cormac
the
grey
"
Set-VMHostAdvancedConfiguration -Name "Config.Etc.issue" -Value $msg

Retrieve /etc/motd for ESXi

Get-VmHostAdvancedConfiguration -Name "Config.Etc.issue"

Set /etc/motd for ESXi

Set-VMHostAdvancedConfiguration -Name "Config.Etc.motd" -Value $msg