MSA 1000, HA kit and SQL

[Debra H]

We recently purchased a MSA 1000 San Kit with the HA kit. We have it configured to connect to 2 servers. One server manages the array and also manages a MySql database that takes hits all night long. The other server has several MS SQL databases. Whenever we initiate a backup through the MS SQL Enterprise Manager, we are writing to the same drive space on the array. Once the backup starts, we start to receive several errors from both the SAN array and the MS SQL server. The redundant controller beccomes active. 2 minutes later it swaps again. This continues until the MS SQL backup job is finished. What could be wrong?

[BR894765]

I have seen such situation with improper cabling, when fibre switches was connected to each other.

Also without special clusterware servers must write only to drive space that they "own".

[Debra H]

I was told the cabling did not matter as long as each card was plugged into a switch and each controller was plugged into switch. Are there settings for which is primary?

[BR894765]

What errors you got from array? What firmware version do you use?

[Debra H]

Firmware version on controller is 4.48.B342. We frequently receive the message below. It continuously goes from active to standby, active to standby. Eventually connections to drives fail. We can't backup our SQL db unless we reboot everything.

Description:
A 'Redundant Controller Active' trap signifies that the Storage Agent has detected that a backup array controller in a duplexed pair has switched over to the active role.

Details:
Controller Role 'Active'
Chassis Name 'SGM053801D'
Slot # 2
MEMORY 512
Model 3
Serial Number 'P56350HX3S90IQ

[Uwe Zessin]

> I was told the cabling did not matter as long as each card was plugged into a switch and each controller was plugged into switch.

That is simply wrong. The 'ping-pong' strongly suggests a setup error.

The 'first' Fibre Channel adapter in the server as detected by the OS must connect to the first MSA controller and it must not have access to the second controller.

[Debra H]

We do have it setup this way. Each server has 2 HBA cards. HBA card A connects to Switch A, HBA card B connects to Switch B and the Switch connects to the controller. Same thing for second server. I am thinking of removing the multipath and redundancy.

[BR894765]

HBA A from both servers must be connected to Switch A and this switch must be connected to one MSA controller, HBA B from both servers -- to switch B, switch B -- to another MSA controller. And do not put any link between switches.

[Debra H]

What determines which HBA is A or B? Also, did 4.48 firmware address this issue?

[BR894765]

You can find cabling examples in Modular SAN Array 1000 User Guide.
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&locale=en_US&docIndexId=179911&taskId=101&prodTypeId=12169&prodSeriesId=377751