NOTE
Configuring your Environment for Software RAID
Configuring Multiple Paths to Storage
Configuring Multiple Paths to Storage
HP requires that you configure multiple paths to the storage device using the QLogic HBA driver as it has inbuilt multipath capabilities. Use the install script with the
For more information on installing the QLogic HBA driver, see the HP StorageWorks Using the QLogic HBA driver for
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c001
69487/c00169487.pdf
You need to register with
Setting the Value of the Link Down Timeout Parameter
After you install the QLogic HBA driver, you must set the Link Down Timeout parameter of the QLogic cards to a duration equal to the cluster reformation time. When using the default values of heartbeat interval and node timeout intervals of Serviceguard for Linux with a Quorum server, this parameter must be set to 40 seconds. Setting this parameter to 40 seconds, which is the recommended value, prevents further writes to the active half of the mirror disk set when the other fails. If this failure were to also bring down the node a few moments later, then the chance of losing these writes are eliminated.
This parameter prevents any data being written to a disk when a failure occurs. The value of this parameter must be set such that the disks are inaccessible for a time period which is greater than the cluster reformation time. This parameter is important in scenarios where an entire site is in the process of going down. By blocking further writes to the MD device, the two disks of the MD device remain current and synchronized. As a result, when the package fails over, it starts with a disk that has current data. You must set a value for this parameter for all QLogic cards.
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