Issue: Backup and/or Restore operations in ASM may fail if there is more than one File Volume (partition)
configured on an iSCSI-Based LUN (disk)
Workaround: Do not perform backup or restore operations in ASM on storage where more than one File
Volume is hosted on a single iSCSI LUN. ASM never provisions more than one volume on iSCSI LUNs, and
this situation will not be encountered for storage provisioned by ASM.
Issue: Migrating storage using ASM may cause an error during volume creation
When migrating storage using the ASM, the
Create Volume
task may fail.
Workaround: This is due to an error in Microsoft Virtual Disk Service (VDS). Restart the specific wizard to
launch the task again.
In some cases, the
Create Volume
task will fail after storage has already been provisioned and an iSCSI LUN
has been created on the storage system. If this occurs, running the wizard again will result in another iSCSI
LUN (vhd file) being created on the storage system and the initial iSCSI LUN will take up extra space without
being utilized. For information about how to properly delete the unused iSCSI LUN, see the white paper
Reclaiming storage on the HP StorageWorks Automated Storage System
at
http://h71028.www7.hp.com/
ERC/downloads/4AA1-1026ENW.pdf
.
Issue: Data protection settings are not modified for storage areas that are promoted by ASM
If data protection settings (replication, snapshots, and backup) are applied to a remote user-defined storage
area, and then a SQL Server database or Exchange database is manually migrated to this storage area, ASM
automatically promotes the application to a SQL or Exchange Storage area during the discovery process.
ASM does not, however, adjust the data protection settings that were originally applied to the area. This may
lead to failures when taking snapshots, running backups, or running replication.
Workaround: When SQL Server or Exchange databases that are part of user-defined storage areas are
promoted to SQL or Exchange storage areas in ASM, disable and delete all data protection settings for those
areas (replication, snapshots, and backup) and reset them using ASM.
Issue: Replicating a storage component whose application data exists in a single iSCSI LUN results in extra
space utilization on the replication target
When a single iSCSI LUN is presented to a SQL or Exchange server, the database file and database transaction
log file are both created on the volume contained in the iSCSI LUN. If the iSCSI LUN was created on the
storage system as a user-defined application, ASM will discover that the database files are now in the volume
and it will promote the user-defined application to a SQL Server or Exchange application instance. If the SQL
Server or Exchange application instance is replicated to another system, the iSCSI LUN is replicated to the
target system twice: once for the database file and again for the log file.
In general, the amount of space used on the replication target is equal to the size of each iSCSI LUN that
contains multiple components multiplied by the number of components in that iSCSI LUN. If multiple components
exist in multiple iSCSCI LUNs, the sum of the product of the sizes is the total consumed space. Snapshot space
usage is similar.
For example, a single iSCSI LUN of 200MB that contains a volume that has both the database file and the
log file would consume 400 MB of space on the replication target (200MB x 2 = 400MB). Likewise, an
Exchange server with one storage group of three mail stores on one iSCSI LUN of 500MB and the log and
public store on a separate iSCSI LUN of 250 MB would consume 2000MB of space on the replication target
(500MB x 3 + 250MB x 2).
Workaround: As a best practice, when configuring storage for SQL Server and Exchange databases, create
the database files on one iSCSI LUN and create the associated log and system files on a separate iSCSI LUN.
This way, when storage areas are replicated, there will be one component per iSCSI LUN and space will be
utilized on the replication target more efficiently.
6
Summary of Contents for X1600 - StorageWorks Network Storage System 5.4TB SAS Model NAS Server
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