Transparent Page Sharing (TPS) is disabled by default in latest ESXi 5.5 patch

I just heared Transparent Page Sharing (TPS) is disabled by default in latest ESXi 5.5 patch. You may concern about that if your IT budget is tight since it means you need more memory for heavy virtual machines.

听说ESXi 5.5最新的patch里把TPS禁用了,专门研究了一下。觉得这对IT预算紧张的企业可能是个坏消息,因为这意味着你需要更多的内存应付大型虚拟机。

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Incompatible device backing specified for device ‘x’

It’s easy to find a solution for this particular problem. VMware has a KB for this error. Somehow it’s not my case. I don’t know what’s the exactly root cause but you can try vMotion the virtual machine to other host and give a try.

Chinese Version
这个问题的解决方案很容易找到,VMware有一个知识库。但不知道为什么,我遇到的问题没法用此知识库解决。我通过vMotion虚拟机到其他ESXi 主机解决此问题,也不知道具体原因是什么。

The CPU has been disabled by the guest operating system

Few weeks ago, our database virtual machines got randomly failed. There was error message “The CPU has been disabled by the guest operating system. Power off or reset the virtual machine.” on VM events. I didn’t find any abnormal on vmkernel, hostd and vm logs. Finally our Linux team identified it’s a Linux kernel bug. Please refer to BUG at block/blk-core.c:NNNN! in blk_requeue_request or blk finish_request.

The bug only present on RedHat 6 on ESXi 5.5 with VMware Paravirtual SCSI drivers.

 

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Nodes in the ESXi cluster may report corruption after reboot host or attach device

VCE just released a new KB vce2563 to description the issue.

If your ESXi 5.x hosts is connected on VMAX running Enginuity 5876.159.102 and later, you may see this particular issue after reboot ESXi host or attach storage if you enabled block delete feature of VAAI.

To check the option status you can run following command on PowerCLI:

 Get-VMHost -Location cluster name | Get-VMHostAdvancedConfiguration -Name VMFS3.EnableBlockDelete

How to setup NTP services by PowerCLI

NTP service is very important for troubleshooting, vmkernel log timestamp is incorrect if your NTP service is not running and ESXi system time is wrong. It can also impact to VM system time even you disable time synchronization on VMware Tools since VM still need to sync time with ESXi after awake from suspended status, finish vMotion, or revert from snapshot.

I know it’s simple to configure NTP services on single how, what if you want to configure NTP service on massed hosts?

Basically we have 3 steps to make sure NTP service working properly:

  • Configure NTP server IP address.
  • Bring up NTP service.
  • Set services startup along with ESXi system.

Let’s try PowerCLI:

Get-VMHOST -Location Cluster Name | Add-VMHostNtpServer -NtpServer “NTP server address

Get-VMHOST -Location Cluster Name | Get-VMHostService| Where-Object {$_.key -eq “ntpd”} | Start-VMHostService

Get-VMHOST -Location Cluster Name | Get-VMHostService| Where-Object {$_.key -eq “ntpd”} | Set-VMHostService –Policy On