Planet v12n not updating
Updates such as this one typically include a number of system improvements and also all of the patches available in-between it and the previous update available.After updating from v Center 4.1 to 5.0 quite some time ago, I noticed how my custom scripts collecting historical VM-level performance statistics suddenly logged zero-values for the IOPS counters datastore.number Read Averaged.average and datastore.number Write Averaged.average of all VMs.Querying for these metrics in any rollup interval yields nothing, the values are only available in realtime mode: Unfortunately it seemed like I was out of luck, I thought about opening a Support Request or rather “Feature Request” but did end up procrastinating and forgetting, not really expecting much out of a mere Feature Request case anyways.But while engaging support for some other problem, I asked about this as a sidenote and the supporter immediately recalled two KB articles: Change the collection level for Storage DRS and SIOC data counters in v Sphere 5.0 by using the Level Mapping Utility Change the collection level for Storage DRS and SIOC data counters in v Sphere 5.0 Update 1 by using the Level Mapping Utility These articles provide a small Powershell script, the “Level Mapping Utility” which allows you to manipulate the statistics level affiliation of any performance counter, or at least it seems so. First we can confirm the current statistics level of all counters and we’ll see how the “Per Device Level” (per VM in my case) of the IOPS counters I’m interested in is at 3.Not so good: The Set-Function to actually change statistics levels can read from a CSV-File about the counters and how they are supposed to be manipulated.The by default provided CSV-File will change the statistics level for a lot of other counters too: As I’m only interested in two distinct counters for now and don’t want to blow up my database too much, I simply removed all other lines and ran it with that.
We’ve done extensive testing and most of the time it runs quite well, but we’ve found a few cases, where some tuning can make all the difference.
I was recently involved with a scenario where a Linux application on Hyper-V (Windows Server 2016) was showing benchmarks of between 30-35% slower than other hypervisors.
We instinctively felt something was wrong, so we rolled up our sleeves and got to work.
In each of these sections you can find detail on which Hyper-V features are supported in which Linux versions.
Bottom line again, is that in this case, simply upgrading LIS to the current version of 4.1.3 delivered a 10% performance improvement.