vSAN architecture includes critical services and mechanisms and it’s good to know and understand the key components that operates in the background. vSAN versions have changed over the years and there are newer and newer features but the architecture and core components are the same. So what happens at the lower level when we create […]
Let’s quick remind ourselves I/O flow and how do checksum calculation and disk encryption work in conjunction with deduplication and compression on vSAN All-Flash cluster while creating/modifying new vmdk. 1. Checksum – functionality to avoid data integrity issues – is calculated before writing data (the block) to the caching tier. vSAN created 5-byte checksum for […]
When you add new vSphere cluster to the management or VI workload domain and provide expired or invalid vSAN license key, the subtask ‘Apply vSAN License in vCenter Server’ will fail: In /var/log/vmware/vcf/domainmanager/domainmanager.log you can find more details: 2021-04-21T11:53:22.184+0000 WARN [vcf_dm,9f492adb1719ed65,0ae2] [c.v.e.s.c.c.v.vsphere.VcManagerBase,dm-exec-8] VSAN license verification failed – assuming vSAN license not applied 2021-04-21T11:53:22.184+0000 DEBUG [vcf_dm,9f492adb1719ed65,0ae2] […]
One of the many steps performed when you try to unstretch vSAN cluster is disabling stretch cluster mode in all ESXi hosts. It’s done automatically so you don’t need to worry about that but in my case I needed to do that manually. When you run into an below error during ova deployment, definitely it’s […]
First run this command to dump the instance names for all instances in the system: and now just execute the command (replace ‘lsi_mr3-544a842043a54a00/LSI Incorporation’ with the Key Value Instance you received as the output of previous command) : That’s it š Any questions, comments? Just ping me.
In this blog post i will describe what is going on in the background when ‘./sos –stretch-vsan’ command is initiated. It’s not a rocket science because all these steps are done when you stretch cluster manually but i thought it can be helpful for someone who never did that. Some tasks are described as ‘all […]
This time very short and quick post:) If you see such error message (as below) in vCenter when adding or replacing VMware vSAN 6.7 Witness Appliance, just remember: CHECK YOUR vSAN Witness Appliance VERSION AND BUILD. The witness host must be capable of running the same version of ESXi as vSAN data nodes. 2019-11-08T18:24:31.613Z info […]
I’ve just received an email with congratulations on winning a copy of VMware vSAN 6.7 U1 Deep Dive by Cormac Hogan and Duncan Epping! Thanks VMware vSAN team
vSAN Health Check plug-in is not available and displays an error: “The vCenter server is not responding, please check your setup (status code 503)” Starting vsan-health service manually ended with general error: “An error occured while starting service” Group permission on /etc/vmware-vpx/ssl is correct. This issue is not related with Dell OMI in this version of […]
Next book to the virtualization’s required reading list added: VMware vSphere 6.5 Host Resources Deep Dive