HP StorageWorks 8000 Storing Microsoft SQL Server Databases on the NAS 8000 - Page 5

fast and efficient data access, and utilizes RAID 0/1 or HP AutoRAIDtm technology to protect the data on the storage subsystem's hard drives. AutoRAIDtm combines RAID levels 0/1 and 5DP, controlled and configured in "real time" by the VA 7xxx firmware, to provide total protection/recoverability in the event of single hard disk failures and almost all two (2) simultaneous hard disk failures (per redundancy group). The VA 7xxx also can reserve up to the two largest hard drives worth of space (across all hard drives in a redundancy group) for use as "hot spares" to allow automatic recovery of failed drive(s). Please note that utilizing RAID levels will reduce the total amount of storage available. The specific settings for controlling the VA 7xxx RAID level, hot spares and other configuration parameters are accessible from the Command View NAS / Command View VA GUIs. Use of the NAS 8000 also means that server CPU cycles once needed to manage/maintain a complex storage environment can be utilized for better database performance, while the NAS 8000 provides data protection, availability and reliability. storage management and definition guide defining NAS 8000 storage for Microsoft SQL Server databases The reader is directed to the HP NAS 8000 User's Guide for specific instructions/details on each of the steps listed below, and to the glossary for term definitions. Before defining the storage, it is imperative to plan out the storage use model, including such things as security mode, snapshot space for backups, use of redundancy groups for increasing fault tolerance, active/"hot" spares if needed, RAID settings, etc. Failure to plan may lead to the need for redefining/changing storage definitions later on, which could require a service outage for a short time. If the NAS 8000 is in a direct-attach configuration, the first step in defining storage is the definition of LUNs. If the NAS 8000 is in a SAN-attach configuration, the SAN Management station defines LUNs, so the first step would be to define volume groups. LUNs combine the physical storage from a redundancy group in the VA 7xxx array into a pool of logical storage. Each redundancy group is assigned a different controller as its "primary" controller. The other controller provides a redundant data pathway. The general guidelines for defining LUNs are to make as few LUNs as possible and make the LUNs as large as possible. There is currently a 1 Terabyte limit on LUN size. A NAS 8000 equipped with the VA 7100 array will have only one redundancy group. In this case, unless the NAS 8000 is to be upgraded to a cluster system, or unless there are administrative reasons to do so, no benefit will be realized by creating multiple LUNs. LUNs cannot span redundancy groups, so for a NAS 8000 with a VA 7400, a minimum of two LUNs must be created. The storage pools of both LUNs can be combined into one volume group without a performance penalty. The optimized operating system of the NAS 8000 will always use the most efficient data pathway when accessing the VA 7xxx array - even when all of the storage is combined in a single volume group. There is a slight fault tolerance benefit to implementing the storage of a NAS 8000 with a VA 7400 such that storage is defined along redundancy group boundaries. By not allowing any volume group to include LUNs from both redundancy groups, the number of hard drive failures that can occur before the entire VA 7400 array goes down is essentially doubled. The use of "Hot Spares" and AutoRAIDtm is functionally independent to each redundancy group. This means that if three drives in the same redundancy group were to crash (causing the entire redundancy group to be unavailable), the other redundancy group would still be active with its data available. However, if any volume group contains LUNs from both redundancy groups and one redundancy group goes down, of necessity, the entire array is down. For more information about fault tolerance and other VA 7xxx topics, please refer to the HP Virtual Array User and Service Guide (located off of either the VA 7100 or VA 7400 home page). The next step in defining storage (or first step if in SAN-attach configuration) is to create the volume group(s). A volume group is comprised of one or more LUNs. A LUN is always fully contained inside a single volume group. For example, it is possible to create two LUNs, one on each redundancy group and then create one volume group using both LUNs. If a hard drive was added to the array enclosure after storage had been defined, the space of the hard drive could be made available by creating a new LUN, and then adding that LUN to an existing volume group. Volume groups combine the storage of the LUNs. One possible reason for multiple LUNs/volume groups would be to utilize the NAS 8000 in a heterogeneous environment in which CIFS/SMB shares are being protected with HP Virus Guard Real Time Protection while there are also nfs clients accessing the NAS 8000 storage. See the constraints section below for more details. For the NAS 8000 system that has a VA 7400, multiple volume groups on separate redundancy groups can be used to increase the fault tolerance level. The operating system of the NAS 8000 will always use the most efficient data pathway to access the VA 7xxx array. If the backup or 5