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Breakthrough Visibility

VMware Skyline™ is radically transforming customer support

By: Dale Ferrario

Customers like you that run business-critical operations on VMware environments need an infrastructure that’s always-on and optimized for peak performance. You expect fast, environment-specific remediation recommendations, and proactive analytics that identify problems before they occur.

We’re addressing these needs with VMware Skyline™: an innovative support technology, developed entirely by VMware Engineering, that provides VMware technical support engineers with extreme visibility into your environment.

Imagine if we knew your environment as well as you do. We could tell you – in advance – of a problem you’d have in the future. And then we gave you proactive, prescriptive, and predictive recommendations to fix the issue. And if you do need to call us with a problem, we have the visibility into your environment that lets us quickly diagnose your situation without a lot of effort and hours on your part.

Here’s how it works. Customers with active support subscriptions install the VMware Skyline Collector, a standalone appliance that automatically and securely collects product usage data such as configuration, feature, and performance data.

It then listens for changes, events and patterns and analyzes the information using a robust rules and machine learning engine. The rules engine is where an ever-growing library of support intelligence, product knowledge, and logic is stored to analyze inbound streams of product information.

It will alert when a customer has deviated from a VMware Validated Design or needs to align to a best practice configurations or patch level. Issues identified are fed into the analytics library – consisting of hundreds of detection rules – to allow us to solve the issue for multiple customers.

And you can rest assured knowing that we take privacy and security seriously – VMware Skyline has a robust privacy program. Customer data is transferred to VMware over an encrypted channel and is stored in a secure VMware repository in the US, operated by VMware.

Then the VMware Technical Support Engineer takes the analyzed, environment-specific data to provide prescriptive recommendations back to you to improve your environment’s reliability and stability.

Aligned to Global Services offerings, VMware Skyline is initially available for Premier Support customers with Production Support customer availability coming next year. Today VMware Skyline provides increased visibility for VMware vSphere and VMware NSX environments. Additional products will be added over time.

With minimal administration, a rigorous privacy and security policy, and transformational value, VMware Skyline is a game changer for your support experience with VMware.

Sign up today to join our Managed Access program at https://www.vmware.com/support/services/skyline.html

A look at All Paths Down in vSphere

Today we have a guest post from Karthick Sivaramakrishnan, who is a 3 year veteran at VMware. His primary field of expertise is vSphere Storage and Site Recovery Manager.

This blog post is centered around how ESXi handles unscheduled storage disconnects on vSphere 5.x and 6.x. An unscheduled storage disconnect means some issue in the vSphere environment has led to All-Paths-Down (APD) for a datastore. An APD situation will be seen when ESXi host does not have any path to communicate with a lun on the storage array.

ESXi host can encounter an APD under several conditions. As a result, we may end up having VMs running on a given datastore go down, the host could get disconnected from vCenter, and in worst cases ESXi could become unresponsive.

From vSphere version 5.x and onwards, we are able to discern whether a disconnect is permanent or transient. Ideally a transient disconnect leads to All Paths Down state and ESXi expects the device to have a temporary disconnect. When we see permanent device loss or PDL the device is expected to have a non-recoverable issue like a hardware error or the lun is unmapped.

In the below example we see all iSCSI datastores are in inactive state.

To determine what caused this issue we see ESXi logs, particularly vmkernel and vobd. This issue will be evident in the vmkernel logs.

vmkernel log

2017-01-10T13:04:26.803Z cpu1:32896)StorageApdHandlerEv: 110: Device or filesystem with identifier [naa.6000eb31dffdc33a0000000000000028] has entered the All Paths Down state.

2017-01-10T13:04:26.818Z cpu0:32896)StorageApdHandlerEv: 110: Device or filesystem with identifier [naa.6000eb31dffdc33a000000000000002a] has entered the All Paths Down state.

vobd log

2017-01-10T13:04:26.905Z: [scsiCorrelator] 475204262us: [esx.problem.storage.connectivity.lost] Lost connectivity to storage device naa.6000eb31dffdc33a0000000000000028. Path vmhba33:C0:T1:L0 is down. Affected datastores: “Green”.

2017-01-10T13:04:26.905Z: [scsiCorrelator] 475204695us: [esx.problem.storage.connectivity.lost] Lost connectivity to storage device naa.6000eb31dffdc33a000000000000002a. Path vmhba33:C0:T0:L0 is down. Affected datastores: “Grey”.

From these logs we understand that ESXi host has lost connectivity to the datastore. Any virtual machines using the affected datastore may become unresponsive. In this example while the datastores was mounted on ESXi, we lost the network uplink on the nic that was used for iSCSI connection. This was a transient issue and the datastore came up once the network uplink was restored.

In the below example we see Datastore Black is in inactive state.

If we look into the logs to determine whats going on we see these events.

Vmkernel.log

2017-01-09T12:42:09.365Z cpu0:32888)ScsiDevice: 6878: Device naa.6000eb31dffdc33a0000000000000063 APD Notify PERM LOSS; token num:1

2017-01-09T12:42:09.366Z cpu1:32916)StorageApdHandler: 1066: Freeing APD handle 0x430180b88880 [naa.6000eb31dffdc33a0000000000000063]

2017-01-09T12:49:01.260Z cpu1:32786)WARNING: NMP: nmp_PathDetermineFailure:2973: Cmd (0xc1) PDL error (0x5/0x25/0x0) – path vmhba33:C0:T3:L0 device naa.6000eb31dffdc33a0000000000000063 – triggering path evaluation

2017-01-09T12:49:01.260Z cpu1:32786)ScsiDeviceIO: 2651: Cmd(0x439d802ec580) 0xfe, CmdSN 0x4b7 from world 32776 to dev “naa.6000eb31dffdc33a0000000000000063” failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x25 0x0.

2017-01-09T12:49:01.300Z cpu0:40210)WARNING: NMP: vmk_NmpSatpIssueTUR:1043: Device naa.6000eb31dffdc33a0000000000000063 path vmhba33:C0:T3:L0 has been unmapped from the array

After some time passes you will see this message:

2017-01-09T13:13:11.942Z cpu0:32872)ScsiDevice: 1718: Permanently inaccessible device :naa.6000eb31dffdc33a0000000000000063 has no more open connections. It is now safe to unmount datastores (if any) and delete the device.

In this case the lun was unmapped from the array for this host and that is not a transient issue. Sens data 0x5 0x25 0x0 corresponds to “LOGICAL UNIT NOT SUPPORTED” which indicates the device is in Permanent Device Loss (PDL) state. Once ESXi knows the device is in PDL state it does not wait for the device to return back.

ESXi only checks ASC/ASCQ and if it happens to be 0x25/0x0 or 0x68/0x0, it marks device as PDL.

VMware KB 2004684 has in-depth information around APD and PDL situations. It also talks about planned and unplanned PDL. You can read it here: Permanent Device Loss (PDL) and All-Paths-Down (APD) in vSphere 5.x and 6.x (2004684)

Further on in the hostd logs you will see some additional events that will correlate to storage connection. Look for the below event id’s.

Event ID : esx.problem.storage.connectivity.lost

“esx.problem.storage.connectivity.lost” event indicates a loss in connectivity to the specified storage device. Any virtual machines using the affected datastore may become unresponsive.

Event ID : esx.problem.scsi.device.state.permanentloss

“esx.problem.scsi.device.state.permanentloss” event indicates a permanent device loss.

Purging old data from the vCenter Server database

This video demonstrates how to purge old data from the SQL Server database used by vCenter Server. You would need to perform task if your vCenter database is full.

When the vCenter Server database if full:

You cannot log in to vCenter Server
VMware VirtualCenter Server service may start and stop immediately.

To resolve this issue, we need to manually purge or truncate the vCenter Server database. Details of how to do this and the script to truncate the database is documented in KB article: Purging old data from the database used by vCenter Server (1025914)

vSphere 6.5 is here! What you need to know

vSphere 6.5 has been released for all to download. We’re sure you vSphere users are all eager to install a copy and start kicking the tires, and we’re just as eager to see that you get started on the right foot. With this in mind, we have created the following list of Knowledge Base articles that are brand new, or have been updated for vSphere 6.5

First of all: Download VMware vSphere and Get Your vSphere License Key

KB articles recommended by VMware Support before you start your journey:

For more details on the release please refer to the vSphere 6.5 announcement.

If you are interested in learning more about vSphere 6.5, there are several options:

Read more about vSphere 6.5 at the product pages
Experience vSphere 6.5 with our free 60-day evaluation
Take one of the new online or instructor-led vSphere 6.5 courses

Path failover may not be successful when using Cisco MDS Switches on NX-OS 7.3 and FCoE based HBAs

So I wanted to get this blog post out sooner rather than later as it might effect a significant number of customers. In a nutshell, if you perform array maintenance that requires you to reboot a storage controller, the probability of successful path failover is low. This is effectively due to stale entries in the fiber channel name server on Cisco MDS switches running NX-OS 7.3, which is a rather new code release. As the title suggests, this only affects FCoE HBAs, specifically ones that rely on our libfc/libfcoe stack for FCoE connectivity. Such HBAs would be Cisco fnic HBAs as well as a handful of Emulex FCoE HBAs and a couple others.

Here is an example of a successful path failover after receiving an RSCN (Register State Change Notification) from the array controller after performing a reboot:

2016-07-07T17:36:34.230Z cpu17:33461)<6>host4: disc: Received an RSCN event
 2016-07-07T17:36:34.230Z cpu17:33461)<6>host4: disc: Port address format for port (e50800)
 2016-07-07T17:36:34.230Z cpu17:33461)<6>host4: disc: RSCN received: not rediscovering. redisc 0 state 9 in_prog 0
 2016-07-07T17:36:34.231Z cpu14:33474)<6>host4: disc: GPN_ID rejected reason 9 exp 1
 2016-07-07T17:36:34.231Z cpu14:33474)<6>host4: rport e50800: Remove port
 2016-07-07T17:36:34.231Z cpu14:33474)<6>host4: rport e50800: Port entered LOGO state from Ready state
 2016-07-07T17:36:34.231Z cpu14:33474)<6>host4: rport e50800: Delete port
 2016-07-07T17:36:34.231Z cpu54:33448)<6>host4: rport e50800: work event 3
 2016-07-07T17:36:34.231Z cpu54:33448)<7>fnic : 4 :: fnic_rport_exch_reset called portid 0xe50800
 2016-07-07T17:36:34.231Z cpu54:33448)<7>fnic : 4 :: fnic_rport_reset_exch: Issuing abts
 2016-07-07T17:36:34.231Z cpu54:33448)<6>host4: rport e50800: Received a LOGO response closed
 2016-07-07T17:36:34.231Z cpu54:33448)<6>host4: rport e50800: Received a LOGO response, but in state Delete
 2016-07-07T17:36:34.231Z cpu54:33448)<6>host4: rport e50800: work delete

Here is a breakdown of what you just read:

RSCN is received from the array controller
Operation is now is state = 9
GPN_ID (Get Port Name ID) is issued to the switches but is rejected because the state is 9 (See http://lists.open-fcoe.org/pipermail/fcoe-devel/2009-June/002828.html)
LibFC begins to remove the port information on the host
Port enters LOGO (Logout) state from previous state, which was Ready
LibFC Deletes the port information

After this the ESX host will failover to other available ports, which would be on the peer SP:

2016-07-07T17:36:44.233Z cpu33:33459)<3> rport-4:0-1: blocked FC remote port time out: saving binding
 2016-07-07T17:36:44.233Z cpu55:33473)<7>fnic : 4 :: fnic_terminate_rport_io called wwpn 0x524a937aeb740513, wwnn0xffffffffffffffff, rport 0x0x4309b72f3c50, portid 0xffffffff
 2016-07-07T17:36:44.257Z cpu52:33320)NMP: nmp_ThrottleLogForDevice:3298: Cmd 0x2a (0x43a659d15bc0, 36277) to dev "naa.624a93704d1296f5972642ea0001101c" on path "vmhba3:C0:T0:L1" Failed: H:0x1 D:0x0 P:0x0 Possible sense data: 0x0 0x0 0x0. Act:FAILOVER

A Host status of H:0x1 means NO_CONNECT, hence the failover.

Now here is an example of the same operation on a Cisco MDS switch running NX-OS 7.3 when a storage controller on the array is rebooted:

2016-07-14T19:02:03.551Z cpu47:33448)<6>host2: disc: Received an RSCN event
 2016-07-14T19:02:03.551Z cpu47:33448)<6>host2: disc: Port address format for port (e50900)
 2016-07-14T19:02:03.551Z cpu47:33448)<6>host2: disc: RSCN received: not rediscovering. redisc 0 state 9 in_prog 0
 2016-07-14T19:02:03.557Z cpu47:33444)<6>host2: rport e50900: ADISC port
 2016-07-14T19:02:03.557Z cpu47:33444)<6>host2: rport e50900: sending ADISC from Ready state
 2016-07-14T19:02:23.558Z cpu47:33448)<6>host2: rport e50900: Received a ADISC response
 2016-07-14T19:02:23.558Z cpu47:33448)<6>host2: rport e50900: Error 1 in state ADISC, retries 0
 2016-07-14T19:02:23.558Z cpu47:33448)<6>host2: rport e50900: Port entered LOGO state from ADISC state
 2016-07-14T19:02:43.560Z cpu2:33442)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:02:43.560Z cpu2:33442)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:02:43.560Z cpu58:33446)<6>host2: rport e50900: Port entered LOGO state from LOGO state
 2016-07-14T19:03:03.563Z cpu54:33449)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:03:03.563Z cpu54:33449)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:03:03.563Z cpu2:33442)<6>host2: rport e50900: Port entered LOGO state from LOGO state
 2016-07-14T19:03:23.565Z cpu32:33447)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:03:23.565Z cpu32:33447)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:03:23.565Z cpu54:33449)<6>host2: rport e50900: Port entered LOGO state from LOGO state
 2016-07-14T19:03:43.567Z cpu50:33445)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:03:43.567Z cpu50:33445)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:03:43.567Z cpu32:33447)<6>host2: rport e50900: Port entered LOGO state from LOGO state
 2016-07-14T19:04:03.568Z cpu54:33443)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:04:03.568Z cpu54:33443)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:04:03.569Z cpu32:33472)<6>host2: rport e50900: Port entered LOGO state from LOGO state
 2016-07-14T19:04:43.573Z cpu20:33473)<6>host2: rport e50900: Received a LOGO response timeout
 2016-07-14T19:04:43.573Z cpu20:33473)<6>host2: rport e50900: Error -1 in state LOGO, retrying
 2016-07-14T19:04:43.573Z cpu54:33443)<6>host2: rport e50900: Port entered LOGO state from LOGO state

Notice the difference? Here is a breakdown of what happened this time:

RSCN is received from the array controller
Operation is now is state = 9
GPN_ID (Get Port Name ID) is issued to the switches but is NOT rejected
Since GPN_ID is valid, LibFC issues an Address Discovery (ADISC)
20 seconds later the ADISC sent times out and this continues to occur every 20 seconds

The problem is that the ADISC will continue this behavior until the array controller completes the reboot and is back online:

2016-07-14T19:04:47.276Z cpu56:33451)<6>host2: disc: Received an RSCN event
 2016-07-14T19:04:47.276Z cpu56:33451)<6>host2: disc: Port address format for port (e50900)
 2016-07-14T19:04:47.276Z cpu56:33451)<6>host2: disc: RSCN received: not rediscovering. redisc 0 state 9 in_prog 0
 2016-07-14T19:04:47.277Z cpu20:33454)<6>host2: rport e50900: Login to port
 2016-07-14T19:04:47.277Z cpu20:33454)<6>host2: rport e50900: Port entered PLOGI state from LOGO state
 2016-07-14T19:04:47.278Z cpu57:33456)<6>host2: rport e50900: Received a PLOGI accept
 2016-07-14T19:04:47.278Z cpu57:33456)<6>host2: rport e50900: Port entered PRLI state from PLOGI state
 2016-07-14T19:04:47.278Z cpu52:33458)<6>host2: rport e50900: Received a PRLI accept
 2016-07-14T19:04:47.278Z cpu52:33458)<6>host2: rport e50900: PRLI spp_flags = 0x21
 2016-07-14T19:04:47.278Z cpu52:33458)<6>host2: rport e50900: Port entered RTV state from PRLI state
 2016-07-14T19:04:47.278Z cpu57:33452)<6>host2: rport e50900: Received a RTV reject
 2016-07-14T19:04:47.278Z cpu57:33452)<6>host2: rport e50900: Port is Ready

What is actually happening here is that the Cisco MDS switches are quick to receive the RSCN from the array controller and pass it along to the host HBAs however due to a timing issue the entries for that array controller in the FCNS (Fiber Channel Name Server) database are still present when the host HBAs issue the GPN_ID so the switches respond to that request instead of rejecting it. If you review the entry in http://lists.open-fcoe.org/pipermail/fcoe-devel/2009-June/002828.html you see that code was added to validate that the target is actually off the fabric instead of assuming it would be by the RSCN alone. There are various reasons to do this but suffice it to say that it is better to be safe than sorry in this instance.

Unfortunately there is no fix for this at this time, which is why this is potentially so impactful to our customers since it means they effectively are unable to perform array maintenance without the risk of VMs crashing or even corruption. Cisco is fixing this in 7.3(1), which due out in a few weeks.

Here are a couple of references regarding this issue:

Cheers,
Nathan Small
Technical Director
Global Support Services
VMware

Windows 2008+ incremental backups become full backups in ESXi 6.0 b3825889

vmware_tools_icon VMware is actively working to address a recently discovered issue wherein an incremental backup becomes a full backup when backing up Windows 2008 (or higher) virtual machines with VSS-based application quiesced snapshot.

This recent CBT (Changed Block Tracking) issue does not cause any data loss or data corruption.

This issue is well understood and VMware engineering is actively working on a fix.

For more details on this issue and latest status on resolution, please refer to KB article: After upgrading to ESXi 6.0 Build 3825889, incremental virtual machine backups effectively run as full backups when application consistent quiescing is enabled (2145895)

Subscribe to the rss feed for the KB article to ensure you do not miss any update by using this link.