Complexity, in general usage, tends to be used to characterize something with many parts in intricate arrangement.
Wikipedia
Following this disambiguation, and assuming that “many” means N > 2, all systems with at least two or more components are complex. But that would be an exaggeration, right?
Why is information technology complex? Most systems in information technology (IT) are complex. Almost everything we are working with, consists of two or more components, regardless if it is hardware or software.
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.
A customer notified me, that he observed an issue with the space reclamation on two automated desktop pools with linked clones. His environment is based on Horizon View 6.2.1 and vSphere 5.5U3. The error was logged in the View Administrator and the vSphere (Web) Client. In the View Administrator, the following error was visible:
"Failed to perform space reclamation on machine COMPUTER NAME in Pool POOL NAME" Patrick Terlisten/ vcloudnine.de/ Creative Commons CC0
VMware vSphere 6 is now an year old and it was time to update my lab to vSphere 6. The update went smooth, and everything has worked as expected. Some days later, I updated the master VM of a small automated desktop pool. I’m using VMware Horizon 6.2.1 in my lab to deploy a small number of Windows 8.1 VMs for tests, administration etc. The recompose of the pool failed during the guest customization.
Today I saw an interesting behaviour of two Alcatel-Lucent Enterprise OmniSwitch 6450. Both switches has been configured as a stack, but one of the switches showed a flashing ID after the startup, and the stack was not formed. While I checked the logs and the status of the stack, I noticed that the slot number was incorrect. Furthermore the status showed “INC-LIC”.
-> show stack topology Link A Link A Link B Link B NI Role State Saved Link A Remote Remote Link B Remote Remote Slot State NI Port State NI Port ----+-----------+--------+------+-------+-------+-------+-------+-------+------- 1 PRIMARY RUNNING 1 UP 1001 StackB DOWN 0 0 1001 PASS-THRU INC-LIC 2 DOWN 0 0 UP 1 StackA -> show log swlog <snip> THU MAR 03 13:07:29 2016 STACK-MANAGER info == SM == Stack Port A Status Changed: DOWN THU MAR 03 13:07:29 2016 STACK-MANAGER info == SM == NI 0 down notification sent to LAG THU MAR 03 13:08:41 2016 STACK-MANAGER info == SM == Stack Port A Status Changed: UP THU MAR 03 13:08:41 2016 STACK-MANAGER info == SM == Stack Port A MAC Frames TX/RX Enabled THU MAR 03 13:08:42 2016 STACK-MANAGER info Retaining Module Id for slot 2 unit 0 as 1 THU MAR 03 13:08:46 2016 STACK-MANAGER info == SM == An element enters passthru mode (incompatible license) <snip> According to the stack status and the switch logs, there seems to be a problem with the licenses.
Yesterday I did an upgrade of my vCenter Server Appliance 5.5 U3 to 6.0 U1. This was the first step to update my lab infrastructure to vSphere 6.0. A bit late, but better late than never. The update of the VCSA itself went smooth. No problems with certificates, hosts, VMs or PernixData FVP. But then, I discovered two errors on the old vSphere C# client (I know that I should use the Web Client…)
HPE Data Protector stores multiple backup objects on a single Catalyst store item. A backup object can be a volume, a mount point, a database or a virtual machine. You can have multiple backup objects per backup client. If your filesystem backup job has four backup clients, and each client has two volumes, the backup job will contain 8 backup objects. Another example is a single database of a Microsoft SQL or Oracle database server (instance).
Today, I was at a customer to prepare a two node vSphere cluster for some MS SQL server tests. Nothing fancy, just two HP ProLiant BL460c Gen9 blades and two virtual volumes from a HP 3PAR. Each blade had two 400 GB SSDs, two 64 GB M.2 SSDs and a 1 GB MicroSD card. Usually, I install ESXi to a SD card. In this case, a MicroSD card. The SSDs were dedicated for PernixData FVP.
Late last year, I applied a third time for the VMware vExpert program. This title is given from VMware to individuals who have significantly contributed to the community and have spread the message of VMware to customers and partners worldwide. This is nothing you get by passing an exam. It’s given to you by VMware in respect of your work. The vExpert title is something which differates you inside the commnity.
A load balancer is an integral component of (nearly) every VMware Horizon View design. Not only to distribute the connections among a number of connection or security servers, but also to provide high availability in case of a connection or security server failure. Without a load balancer, connection attempts will fail, if a connection or security server isn’t available. Craig Kilborn wrote an excellent article about the different possible designs of load balancing.
