Problems, Challenges, And Constraints - HP StorageWorks 8000 - NAS User Manual

seconds. The "Restricted" setting is the same as "Normal", but allows the "immediate report" feature of
write cache to be disabled as well as flushing the write cache for the associated LUN before completing the
write request. The "Secure" Data Resiliency setting forces write cache to be flushed to the hard drives at a
maximum of every one second, as well as allowing the "immediate report" feature of write cache to be
disabled (like the restricted setting). In order for a write command to disable the "immediate report"
feature, the Data Resiliency setting of the array must be 'Restricted' or 'Secure' and the FUA (Force Unit
Access) bit in the write command must be set. It is recommended that the DBA and the NAS 8000
administrator discuss the merits of each Data Resiliency setting based on the environment and the
applications using the NAS 8000. If database data files are stored on both the SQL Server Windows server
and on the NAS 8000 it is recommended that Data Resiliency be set to 'Secure' as this will further reduce
the vulnerability to multiple NVRAM failure. In order to totally remove the possibility for the data
corruption, place all of the data/log files that can change on the NAS 8000 or all of the data/log files that
can change on the SQL Server.

problems, challenges, and constraints

Without AutoPathing implemented in the NAS 8000, it will be necessary to reboot the NAS 8000 in order
for the secondary controller to provide access to a failed controllers data.
Clustered configurations of the NAS 8000 are currently being tested and are not yet supported.
The use of HP Virus Guard Real Time Protection on a file volume that contains a SQL Server database is not
supported. The use of the Real Time Agent on an active database may cause data corruption to occur. It is
possible to perform a scheduled virus scan on file volumes containing an active database. Performing a
scheduled virus scan during periods of heavy database traffic can cause excessive system performance
degradation. Additionally, if a file volume that is being protected by the Real Time Protection agent of Virus
Guard is located in the same volume group as file volumes containing nfs exports, there may be significant
performance degradation. It is always best, when possible, to ensure that any file volumes with SMB/CIFS
not
shares being protected by VirusPro Real Time Protection are located in volume groups containing any
file volumes with nfs exports.
Currently, when new Windows (CIFS/SMB) shares are defined, or when a snapshot is shared through
CIFS/SMB all CIFS sessions will be lost. In the case of a SQL Server database that is accessing its storage
via CIFS, the database engine will report an unexpected network error. It is always best to shutdown the
database before adding new Windows shares!!
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