By accident, I found a heartbeat/ VLAN issue on a NetScaler cluster at one of my customers. The NetScaler ADC appliances have three interfaces connected to a switch stack. Two of the three interfaces were configured as a channel (LAG). This is a snippet from the config:
set channel LA/1 -tagall ON -throughput 0 -lrMinThroughput 0 -bandwidthHigh 0 -bandwidthNormal 0 ... bind vlan 10 -ifnum 1/3 bind vlan 10 -ifnum LA/1 -tagged bind vlan 54 -ifnum LA/1 -tagged bind vlan 55 -ifnum LA/1 -tagged On the switch stack, the port to which interface 1/3 is connected, is configured as an access port.
A customer of mine got an appliance from a software vendor. The appliance was delivered as ZIP file with a VMDK, a MF, and an OVF file. Unfortunately, the appliance was created with VMware Workstation 6.0 with virtual machine hardware version 6, which is incompatible with VMware ESXi (Virtual machine hardware versions). During deployment, my customer got this error:
unsupported hardware family 'vmx-06' The OVF file includes a line with the VM hardware version.
Yesterday, a customer called me and told me about a scary observation on one of his Exchange 2016 DAG (Database Availability Groups) nodes.
In preparation of a security check, my customer created a snapshot of a Exchange 2016 DAG node. This node is part of a two node Windows Server 2012 R2/ Exchange 2016 CU7 cluster.
That something went wrong was instantly clear, after the first alarm messages were received. My customer opened a console windows and saw, that the VM was booting.
As part of a bigger Microsoft Exchange migration, one of my customers moved the in- and outbound mailflow to a newly installed mail relay cluster. We modified MX records to move the mailflow to the new mail relay, because the customer also switched the ISP. While changing the MX records for ~40 domains, and therefore more and more mails received through the new mail relay cluster, we noticed events from MSExchangeTransport (event id 1021):
One of my customers has started a project to create a Windows 10 Enterprise (LTSB 2016) master for their VMware Horizon View environment. Beside the fact (okay, it is more a personal feeling), that Windows 10 is a real PITA for VDI, I noticed an interesting issue during tests.
The issue For convenience, I adopted some settings of the current Persona Management GPO for Windows 7 for the new Windows 10 environment.
Two 3PAR StoreServs running in a Peer Persistence setup lost the connection to the Quorum Witness appliance. The appliance is an important part of a 3PAR Peer Persistence setup, because it acts as a tie-breaker in a split-brain scenario.
While analyzing this issue, I saw this message in the 3PAR Management Console:
Patrick Terlisten/ vcloudnine.de/ Creative Commons CC0
In addition to that, the customer got e-mails that the 3PAR StoreServ arrays lost the connection to the Quorum Witness appliance.
What is a problem? A problem is an obstacle, that has to be surmounted. Solving a problem is connected with obstacles. Or more general: Problem solving is a process to get from an unsatisfactory to a satisfactory situation.
Most of us get paid for solving problems. It’s irrelevant if you are paid for solving technical problem (e.g. My computer doesn’t work), or if you are paid to create solutions for customers (e.
Last week, I was surprisingly booked by a customer who observed a problem in his network. Unfortunately, colleagues worked on this network some day before (moving servers, routers etc. to a new pair of HP 7509 new core switches).
It was quickly clear, that some of the clients have received the wrong DNS servers from the DHCP server. The environment is a bit unusual. The customer is running two Active Directory domains (root and sub domain) in a single layer 2 broadcast domain.
After updating my lab to VMware vSphere 6.0 U2, one of my hosts continuously thrown an error during an update scan.
Host returns ESX error code 99, unhandled exception has occurred
The first thing I’ve checked was the esxupdate.log on the affected ESXi host. This is the output, that was logged during a scan operation.
2016-04-04T13:42:13Z esxupdate: vmware.runcommand: INFO: runcommand called with: args = '['/sbin/esxcfg-advcfg', '-q', '-g', '/UserVars/EsximageNetTimeout']', outfile = 'None', returnoutput = 'True', timeout = '0.
Today I had a customer call, where a Exchange 2010 backup repeatedly failed. HPE Data Protector was unable to create a differential or incremental backup. For each database, the following error was logged:
[Minor] From: OB2BAR_E2010_BAR@exchangeserver.domain.tld "MS Exchange 2010+ Server" Time: 21.03.2016 20:00:27 [170:313] One or more copies of database DATABASE are already being backed up in a different session. Interestingly, there was no other backup session running. But the night before, the backup jobs failed because of a network failure.
