As some of you may recall about a decade ago I made a proposal to incorporate more intelligence into the end-devices to be able to better react to changing conditions in fabrics. I called it the \”Error Reporting with Integrated Notification\” framework (mind the acronym here. :-)) Basically the intention was to have end-devices check […]
FPIN – The Holy Grail of SAN Stability Read More »
Ever since the dawn of time the storage administrators have been indoctrinated with redundancy. You have to have everything at least twice in order to maintain uptime and be able to achieve this to a level of around 99,999%. This is true in many occasions however there are exceptions when even dual fabrics (ie physically
Cross-fabric collateral damage 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 »
So this week I had an interesting case. As you know the Hitachi arrays have a replication functionality called HUR (Hitachi Universal Replicator) which is an advanced a-synchronous replication solution offered for Mainframe and OpenSystems environments. HUR does not use a primary to secondary push method but rather the target system is issuing reads to
Performance expectations with ISL compression Read More »
Pretty often you get into some sort of mode whereby I forget that there are many youngsters getting their feet wet in the storage arena and some things are hard to grasp on. Traffic flow is one of them so here we go.
Buffer Credits for Newbies Read More »
Sigh….. yet another post to debunk some FCoE marketing and explain in some more details why FCoE is not good for Business Continuity (or business in general).
Why FCoE is bad for Business (Continuity) 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 »
Since a couple of FOS versions ago Brocade wanted to fix the problem Fibre-Channel has by definition called credit back-pressure. The word \”problem\” overstated since in 99.99999% of all fabrics you\’ll never see this anyway. As you know Fibre-Channel is a deterministic architected type of network which requires devices to behave properly. The chaos theory
The Emergency Health Threat (EHT) on Brocade FC fabrics Read More »
