Whenever things goes haywire on an OS or application there are two areas that are looked at first: In a fair few cases the issue is founded to be external from the host systems but when it comes to performance related problems from a storage perspective the entire IO-stack is at play.
HBA Firmware and Drivers – The Storage Grey Area Read More »
I\’ve been focusing on the implications of physical issues a lot in my posts over the last ~2 years. What I haven\’t touched on is logical performance boundaries which also cause extreme grief in many storage infrastructures which lead to performance problems, IO errors, data-corruption and other nasty stuff you do not want to see
Speed mismatch is the death-trap for shared storage Read More »
Very often I get involved in cases whereby a massive amount of host logs, array dumps, FC and IP traces are taken which could easily add up to many gigabytes of data. This is then accompanied by a very synoptic problem description such as \”I have a problem with my host, can you check?\”. I\’m
5-minute initial troubleshooting on Brocade equipment Read More »
After a very busy couple of weeks I\’ve spent some time to dissect the release notes of Brocade FOS 7.1 and I must say there are some really nice features in there but also some that I REALLY think should be removed right away. It may come to no surprise that I always look very critical to whatever come
Brocade FOS 7.1 and the cool features Read More »
In the previous 2 blog-posts we looked at some areas why a fibre-channel fabric still might have problems even with all redundancy options available and MPIO checking for link failures etc etc. The challenge is to identify any problematic port and act upon indications that certain problems might be apparent on a link. So how
One rotten apple spoils the bunch – 3 Read More »
Last week I had another one. A rotten apple that spoiled the bunch or, in storage terms, a slow drain device causing havoc in a fabric. This time it was a blade-center server with a dubious HBA connection to the blade-center switch which caused link errors and thus corrupt frames, encoding errors and credit depletion.
One rotten apple spoils the bunch – 1 Read More »
Why do I keep wondering why companies don\’t maintain their infrastructure. It looks to be more of an exception than a rule to come along software and firmware which is newer than 6 months old. True, I admit, it\’s a beefy task to keep this all lined up but then again you know this in
