Recently I ran into an environment with a couple of VNX5700 systems that were attached to the front-end SAN switches with only two ports per storage processor. The customer was complaining: performance was OK most of the time but at some times during the day the performance was noticeably lower. Analysis revealed that the back-end was coping well with the workload (30-50% load on the disks and storage processors). The front-end ports were a bit (over)loaded and spewing QFULL errors. Time to cable in some extra ports and to rebalance the existing hosts over the new storage paths!
Continue reading “Rebalance VNX storage paths without downtime”
Yesterday I received a call about a drive failure in a CLARiiON CX3-80 storage array. Since every system has at least a couple of hot spares configured, usually this does not pose a problem. But this drive failure happened on drive position 0_0_0: a vault drive failure.
The vault drives host (amongst others) the operating system and configuration of the storage array. They are also used to destage the write cache in case of an event that might threaten data integrity.
Continue reading “CLARiiON CX3 vault drive failure”