Today we had an interesting discussion on the VCDX mailing list. One thing I noticed a while back when I was randomly looking around in “esxtop” was a new field. The field is called ” RESVSTATS and can be enabled in all disk related displays(d, u,v). This will make troubleshooting storage related performance issues a bit easier as the SCSI [...]

After attending Irfan Ahmad’s session on Storage IO Control at VMworld I had the pleasure to sit down with Irfan and discuss SIOC. Irfan was so kind to review my SIOC articles(1, 2) and we discussed a couple of other things as well. The discussion and the Storage IO Control session contained some real gems and before my brain resets [...]

After my initial post about Storage IO Control I received a whole bunch of questions. Instead of replying via the commenting system I decided to add them to a blog post as it would be useful for everyone to read this. Now I figured this stuff out be reading the PARDA whitepaper 6 times and by going through the log [...]

I was preparing a post on Storage I/O Control (SIOC) when I noticed this article by Alex Bakman. Alex managed to capture the essence of SIOC in just two sentences. Without setting the shares you can simply enable Storage I/O controls on each datastore. This will prevent any one VM from monopolizing the datatore by leveling out all requests for I/O that [...]

I was reading about Storage Filters last week and wanted to do a short write up. I totally forgot about it until I noticed this new KB article. The KB article only discusses the LUN filters though and not the other filters that are available today. Currently 4 filters have been made public: config.vpxd.filter.hostRescanFilter config.vpxd.filter.vmfsFilter config.vpxd.filter.rdmFilter config.vpxd.filter.SameHostAndTransportsFilter The first filter [...]

On an internal mailing list we had a very useful discussion around storage migrations when a SAN is replaced or a migration needs to take place to a different set of disks. Many customers face this at some point. The question usually is what is the best approach? SAN Replication or Storage vMotion… Both have its pros and cons I [...]

Don’t know if anyone noticed it or not but with the latest set of patches VMware changed the “Delete All” mechanism that is part of the Snapshot feature. I wrote multiple articles about the “Delete All” functionality as it often led to completely filled up VMFS volumes when someone used without knowing the inner workings. Source When using the Delete [...]