hp storage april 2002 technical white paper NAS 8000 Unix® - Oracle® Users Guide 1
executive summary Hewlett-Packard, in cooperation with Oracle Corporation, has successfully completed the Oracle Storage Compatibility Program testing for the HP NAS 8000 and Oracle 8i on UNIX Servers. The Storage Compatibility Program is designed to verify a NAS device’s ability to safely store the data files for an active Oracle database. Completing the OSCP program indicates that the NAS 8000 will maintain data integrity in the unlikely event of a variety of system and network failures.
executive summary ....................................................................................................................2 for more information ..................................................................................................................2 hp solution overview ..................................................................................................................4 storage management and definition guide...............................................................
hp solution overview Data integrity, reliability, scalability and high performance are top priorities in any database implementation. The use of Network Attached Storage (NAS) devices to store database data files has traditionally been discouraged because it was thought that network instability and perceived vulnerabilities of non-local storage posed too great of a potential risk to data integrity and would greatly reduce system performance.
database. Until recently, conventional wisdom had the database administrator placing different tablespaces/data files on different disk controllers/RAID arrays in an attempt to improve performance through the concurrency allowed by multiple disk interfaces. Multiple hard drives/controllers allowed multiple data pathways for ‘simultaneous’ access to data, as well as allowing multiple copies of critical files to be stored on separate hard drives to protect against some media failures.
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.
nfs: Server NASName OK While these errors are not catastrophic, they may signal the need to ‘tune’ the number of nfsd daemons. Changing the number of nfsd daemons will cause an nfs restart; however, this should not cause an interruption in nfs service.
desirable in certain situations when the data is easily reproducible and/or connect-time charges are a limiting factor. useful mounting options (client) exec – allows execution of binaries from the mount intr – applies to hard mounts only. Allows the nfs client to interrupt an nfs request that is waiting. suid – allows set-user-id bit to function as expected on files in the mounted tree sync – force all access on mount to be performed synchronously.
address of the Oracle server. This will allow that Oracle server to correctly store and access files as the user ‘root’ on the Oracle server. This step must be done prior to installing/storing the Oracle executables on the NAS 8000. location of alert logs and trace files Log and trace files can be an excellent source of information for analyzing problems with a database.
choose the placement of the alert logs and trace files (see above), although the default location will place these files on the Oracle server. moving data files from already existing databases the link method to move data files It may be necessary/desirable to move existing Oracle database data files off of an Oracle server and onto the NAS 8000. There are two ways to accomplish this.
creating new database(s) A new database can be created either through the use of the Oracle Database Administration Assistant GUI (dbassist), or through the use of SQL scripts. The control files, redo logs, archived redo logs and data files can reside solely on the NAS 8000, or can reside on both the NAS 8000 and on the Oracle server.
be implemented to increase data throughput, such as increasing the speed/bandwidth of the network by adding multiple/faster NIC cards, directly attaching the NAS 8000 to the Oracle server through one or more NIC cards with cross over cables, adding additional RAM or additional CPUs to the NAS 8000,etc. increasing available storage in the NAS 8000 Increasing the amount of storage available to a file volume can usually be accomplished without interrupting service.
adding a hard drive to a VA 7400 array If there are empty drive bays in either the VA 74000 disk enclosure or within a previously attached DS2400 enclosure, then storage can be added simply by inserting another hard drive. If the VA 7400 controller is configured to allow “Automatic inclusion” (the default), then the array will automatically detect the new drive and prepare it for use.
hot backups using NAS 8000 snapshots A hot backup (also known as an inconsistent backup) is usually performed by issuing an “alter tablespace” command and placing the tablespaces (all, or whatever the backup plan calls for) into “backup mode”. In this mode, changes to the tablespace are “logged” by the Oracle engine, but not actually written to the tablespace until it is returned to “active mode”. Performing a hot backup leaves the database in an active state, available for user access.
disks. Before the data is flushed from the write cache of the NAS 8000, there is a catastrophic failure that destroys all NVRAM in the NAS 8000. When the NAS 8000 is recovered and the database is restarted, the data will be in an inconsistent state because data located on the server from the transaction was modified, but data located on the NAS 8000 was not.
This Paper applies to the following NAS 8000 configurations: Date Date NAS 8000 Configuration | OSCP Testing Completed | Certified Oracle compatible NAS 8000 w/VA 7100 | May 21, 2002 | NAS 8000 w/VA 7400 | May 21, 2002 | storage diagram for VA 7100 This diagram depicts physical storage as a single redundancy group – because this is a VA 7100.
storage diagram for VA 7400 (single volume group) Hard Drives in Redundancy Group 1 Hard Drives in Redundancy Group 2 Volume Group: VG1 LUN 1 File Vol: Gen Nfs Exports: /ExportPaths File Vol: DB Nfs Exports: /Ora_Archs /Ora_Data /Ora_Sys /Ora_Index /Ora_Rollbk /Ora_Redo LUN 2 This diagram depicts physical storage divided into two redundancy groups. Hard drives in the odd numbered drive bays are in redundancy group 1. Hard drives in the even numbered drive bays are in redundancy group 2.
storage diagram for VA 7400 (extra fault tolerance) Hard Drives in Redundancy Group 1 Volume Group: VG1 Hard Drives in Redundancy Group 2 Volume Group: VG2 LUN 1 LUN 2 File Vol: Gen_1 File Vol: Gen_2 Exports: /ExportPaths Exports: /ExportPaths File Vol: OraData File Vol: OraLogs Exports: /Ora_Arc_Logs /Ora_Data /Ora_Sys Exports: /Ora_Index /Ora_RollBack /Ora_Redo This diagram depicts physical storage divided into two redundancy groups.
glossary AutoRAIDtm – Combination of RAID Levels 0, 1 and 5DP implemented by the firmware of the VA 7xxx controller to provide automatic data protection on VA 7xxx hard drives. CIFS/SMB – (Common Internet File System / Server Message Block). Protocols used to access non-local storage over a network. Primarily used by Windows based systems. Consistent Backup –A backup taken after the database has been shutdown and no changes are taking place to any database files.
