vSphere 6.5 Update 1 – What’s in it for Service Providers

Late last week VMware released vSphere 6.5 Update 1 which included updated builds of both vCenter and ESXi and as per usual I will go through some of the key features and fixes that are included in the latest versions of vCenter and ESXi. When looking through the release notes I generally keep an eye out for improvements that relate back to Service Providers who use vSphere as the foundation of their Managed or Infrastructure as a Service offerings. This update also contains an update to vSAN which is now at 6.6.1 so I’ll spend some time looking at what’s been added there.

 

New Features and Enhancements:

Without question this is a significant patch release for vCenter and ESXi and the length of the release notes is testament to that point. In terms of new features there isn’t anything groundbreaking but there are a few nice additions like being able to run the VCSA GUI and CLI installers on Windows 2012 and 2012 R2 as well as 2016 and macOS Sierra and Ubuntu 17.04 OS is supported for Guest OS Customization. vCenter now supports Microsoft SQL Server 2014 SP2 2016 and SP1 as well as some increased configuration maximums supporting Linked Mode with 15 vCenter Instances, 5000 ESXi hosts and 50,000 powered on virtual machines.

Ability to Upgrade or Migrate from vCenter 6.0 Update 3:

This release addresses the previous limitation in the upgrade and migration path for those running vSphere 6.0 U3 in going to vSphere 6.5. I know this will make a lot of providers happy as I know a lot that had to go to 6.0 Update 3 to address existing bug in the platform but where not yet ready or able to go to 6.5 at the time.

HTML5 Client Update:

The HTML5 Web Client has gotten it’s own update that brings it up to speed with the 3.15 Fligng version however it’s still partially functional which remains somewhat frustrating…The online documentation for supported functionality has been updated to vSphere 6.5U1 and is available here.

The list below is of the main updates in this release.

  • DRS/HA VM overrides
  • SDRS rules
  • Content Library – further actions
  • Roles and Global Permissions
  • Download multiple files as zip
  • Distributed Switch – further actions
  • Fault Tolerance
  • SPBM
  • VM Hardware – further items
  • Apply Customize Guest OS during Clone
  • VM Migration – further actions (compute+storage, Cross VC, batch)
vSAN Features:

For service providers, vSAN 6.6 was another major release that sured up vSANs status as a serious storage platform for service provider platforms.

vSAN 6.6.1 introduces three key new features:

  • VMware vSphere Update Manager (VUM) integration
  • Performance Diagnostics in vSAN Cloud Analytics
  • Storage Device Serviceability enhancement

The ability to upgrade with VUM is a nice touch and continues to improve on the usability and manageability of vSAN. For a full look at what’s new in this release for vSAN 6.6.1 head to this blog post.

Resolved Issues:

There are a bunch of resolved issues in this release and I’ve gone through the rather extensive list to pull out the biggest fixes that relate to my experience in service provider operations and have also extended this to include fixes that relate to backup operations. The majority of what I pick out related to storage, networking hosts and VM operations…the core of any platform, but even more important in the service provider world. The ones in red are specific fixes that relate to issues that iv’e come across…good to see them addressed!

vCenter:
  • First-boot failure occurs when upgrading from vSphere 5.5 or 6.0 to vSphere 6.5 on Windows If an older version of the OpеnSSL DLLs are installed, upgrading to vSphere 6.5 fails to run because the older DLL versions are loaded
  • Affinity rules configured on vCenter Server 5.5 can cause crashes after upgrading to vCenter Server 6.5 Migrating a VM with affinity rules configured while on vCenter Server 5.5 to a cluster that has affinity rules configured on vCenter Server 6.0 or 6.5 can cause vCenter Server to crash.
  • VM Snapshot Size (GB) alarm is not triggered after the VM is powered on. VM Snapshot Size (GB) alarm is reset if the virtual machine is shut down. Alarm fails to trigger after the VM is powered on. This issue occurs in alarms based on VM Snapshot (GB) and Vm Total Size on Disk because their status is altered when the power state of the VM is changed. This issue occurs because disk usage of a VM is the same regardless of the VM power state.
  • When you add ports to a vSphere Distributed Switch you get an error Because of a race condition, when you add ports to a vSphere Distributed Switch you get the error message: Cannot create a new port because number of ports exceeds 2147483647, maximum number of ports allowed on vDS.
  • A runtime exception “Unable to retrieve data about the distributed switch” might occur while upgrading vSphere Distributed Switch (vDS) from 5.0 to 6.5 version When you try to upgrade an existing distributed switch after the vCenter upgrade is completed, the runtime exception Unable to retrieve data about the distributed switch might occur in the wizard and the distributed switch cannot be upgraded. The exception is a result of unexpected value NULL for a LACP property of the distributed switch, instead of TRUE or FALSE, as LACP is not supported for the current version of vSphere Distributed Switch.
  • Host configuration might not be available after vCenter Server restarts After a vCenter Server restart, the host configuration might not be available if vCenter Server cannot communicate with the host. After connectivity is restored, the configuration becomes available.
  • OVF tool fails to upload OVF or OVA files larger than 10 GB If you use OVF tool fails to upload OVF or OVA files larger than 10 GB, the upload might fail.

ESXi:

  • Virtual machine crashes on ESXi 6.5 when multiple users log on to Windows Terminal Server VM Windows 2012 terminal server running VMware tools 10.1.0 on ESXi 6.5 stops responding when many users are logged in.vmware.log will show similar messages to2017-03-02T02:03:24.921Z| vmx| I125: GuestRpc: Too many RPCI vsocket channels opened.
    2017-03-02T02:03:24.921Z| vmx| E105: PANIC: ASSERT bora/lib/asyncsocket/asyncsocket.c:5217
    2017-03-02T02:03:28.920Z| vmx| W115: A core file is available in "/vmfs/volumes/515c94fa-d9ff4c34-ecd3-001b210c52a3/h8-
    ubuntu12.04x64/vmx-debug-zdump.001"
    2017-03-02T02:03:28.921Z| mks| W115: Panic in progress... ungrabbing 
  • An ESXi host might fail with purple diagnostic screen when collecting performance snapshots
    An ESXi host might fail with purple diagnostic screen when collecting performance snapshots with vm-support due to calls for memory access after the data structure has already been freed.An error message similar to the following is displayed:
  • Full duplex configured on physical switch may cause duplex mismatch issue with igb native Linux driver supporting only auto-negotiate mode for nic speed/duplex setting
    If you are using the igb native driver on an ESXi host, it always works in auto-negotiate speed and duplex mode. No matter what configuration you set up on this end of the connection, it is not applied on the ESXi side. The auto-negotiate support causes a duplex mismatch issue if a physical switch is set manually to a full-duplex mode.
  • An ESXi host might fail with a purple screen and a Spin count exceeded (refCount) – possible deadlock with PCPU error An ESXi host might fail with a purple screen and a Spin count exceeded (refCount) - possible deadlock with PCPU error, when you reboot the ESXi host under the following conditions:
    • You use the vSphere Network Appliance (DVFilter) in an NSX environment
    • You migrate a virtual machine with vMotion under DVFilter control
  • A Virtual Machine (VM) with e1000/e1000e vNIC might have network connectivity issues For a VM with e1000/e1000e vNIC, when the e1000/e1000e driver tells the e1000/e1000e vmkernel emulation to skip a descriptor (the transmit descriptor address and length are 0), a loss of network connectivity might occur.
  • An ESXi host might stop responding when you migrate a virtual machine with Storage vMotion between ESXi 6.0 and ESXi 6.5 hosts The vmxnet3 device tries to access the memory of the guest OS while the guest memory preallocation is in progress during the migration of virtual machine with Storage vMotion. This results in an invalid memory access and the ESXi 6.5 host failure.
  • Modification of IOPS limit of virtual disks with enabled Changed Block Tracking (CBT) fails with errors in the log files To define the storage I/O scheduling policy for a virtual machine, you can configure the I/O throughput for each virtual machine disk by modifying the IOPS limit. When you edit the IOPS limit and CBT is enabled for the virtual machine, the operation fails with an error The scheduling parameter change failed. Due to this problem, the scheduling policies of the virtual machine cannot be altered. The error message appears in the vSphere Recent Tasks pane.You can see the following errors in the /var/log/vmkernel.log file:2016-11-30T21:01:56.788Z cpu0:136101)VSCSI: 273: handle 8194(vscsi0:0):Input values: res=0 limit=-2 bw=-1 Shares=1000
    2016-11-30T21:01:56.788Z cpu0:136101)ScsiSched: 2760: Invalid Bandwidth Cap Configuration
    2016-11-30T21:01:56.788Z cpu0:136101)WARNING: VSCSI: 337: handle 8194(vscsi0:0):Failed to invert policy
  • When you hot-add an existing or new virtual disk to a CBT (Changed Block Tracking) enabled virtual machine (VM) residing on VVOL datastore, the guest operation system might stop responding When you hot-add an existing or new virtual disk to a CBT enabled VM residing on VVOL datastore, the guest operation system might stop responding until the hot-add process completes. The VM unresponsiveness depends on the size of the virtual disk being added. The VM automatically recovers once hot-add completes.
  • When you use vSphere Storage vMotion, the UUID of a virtual disk might change When you use vSphere Storage vMotion on vSphere Virtual Volumes storage, the UUID of a virtual disk might change. The UUID identifies the virtual disk and a changed UUID makes the virtual disk appear as a new and different disk. The UUID is also visible to the guest OS and might cause drives to be misidentified.
  • An ESXi host might become unresponsive if the VMFS-6 volume has no space for the journal When opening a VMFS-6 volume, it allocates a journal block. Upon successful allocation, a background thread is started. If there is no space on the volume for the journal, it is opened in read-only mode and no background thread is initiated. Any intent to close the volume, results in attempts to wake up a nonexistent thread. This results in the ESXi host failure.
  • SSD congestion might cause multiple virtual machines to become unresponsiv Depending on the workload and the number of virtual machines, diskgroups on the host might go into permanent device loss (PDL) state. This causes the diskgroups to not admit further IOs, rendering them unusable until manual intervention is performed.
  • Unable to collect vm-support bundle from an ESXi 6.5 host Unable to collect vm-support bundle from an ESXi 6.5 host because when generating logs in ESXi 6.5 by using the vSphere Web Client, the select specific logs to export text box is blank. The options: network, storage, fault tolerance, hardware etc. are blank as well. This issue occurs because the rhttpproxy port for /cgi-bin has a value different from 8303.This issue is resolved in this release.
  • vSphere Storage vMotion might fail with an error message if it takes more than 5 minutes The destination virtual machine of the vSphere Storage vMotion is incorrectly stopped by a periodic configuration validation for the virtual machine. vSphere Storage vMotion that takes more than 5 minutes fails with the The source detected that the destination failed to resume message.
    The VMkernel log from the ESXi host contains the message D: Migration cleanup initiated, the VMX has exited unexpectedly. Check the VMX log for more details.

vSAN:

  • Hosts in a vSAN cluster have high congestion which leads to host disconnects When vSAN components with invalid metadata are encountered while an ESXi host is booting, a leak of reference counts to SSD blocks can occur. If these components are removed by policy change, disk decommission, or other method, the leaked reference counts cause the next I/O to the SSD block to get stuck. The log files can build up, which causes high congestion and host disconnects.
  • vSAN cluster becomes partitioned after the member hosts and vCenter Server reboot If the hosts in a unicast vSAN cluster and the vCenter Server are rebooted at the same time, the cluster might become partitioned. The vCenter Server does not properly handle unstable vpxd property updates during a simultaneous reboot of hosts and vCenter Server.
  • Large File System overhead reported by the vSAN capacity monitor When deduplication and compression are enabled on a vSAN cluster, the Used Capacity Breakdown (Monitor > vSAN > Capacity) incorrectly displays the percentage of storage capacity used for file system overhead. This number does not reflect the actual capacity being used for file system activities. The display needs to correctly reflect the File System overhead for a vSAN cluster with deduplication and compression enabled.

It’s also worth reading through the Known Issues section as there is a fair bit to be aware of in Update 1 and that remain from the GA.

Happy upgrading!

References:

https://docs.vmware.com/en/VMware-vSphere/6.5/rn/vsphere-esxi-651-release-notes.html

https://docs.vmware.com/en/VMware-vSphere/6.5/rn/vsphere-vcenter-server-651-release-notes.html

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