HP StorageWorks 9100 Extreme Data Storage System administration guide V1.0.2 (AN540-96018, February 2010)

In Linux, a LUN appears as a /dev/cciss device. However, these device numbers are only relevant
within a given server. Each server might assign a different /dev/cciss device number to a given
LUN.
For use within the Matrix software, a LUN is “imported” by the Matrix software and mapped to a /
dev/psd device. The psd device number is the same for all members of the Matrix cluster. The
create filesystem command automatically imports LUNs and they are mapped together with
psd devices.
Filesystems
The underlying storage for a given filesystem is located on a single storage block (array). A filesystem
cannot span two storage blocks. Unless otherwise specified, by default the factory pre-configures
storage blocks with two filesystems, each using 32 TB of disk space. When you specify the size of
filesystem, it must be a multiple of the LUN size. See Creating a filesystem for more information.
Alerts
The HP ExDS9100 Storage System can be configured to send an e-mail to designated addresses
when specific events occur. You can use this feature to warn about critical failures in the system. You
can specify what types and severity of events trigger an e-mail warning, as well as the addresses to
which the warnings are sent, by creating e-mail alert filters. A mail server on your site network is
required to relay the e-mail messages from the HP ExDS9100 to the e-mail addresses specified on
the alerts. The mail server is typically set up for you during system installation.
Utility database
The utility database contains critical configuration and status information about the HP ExDS9100
system. If the database becomes corrupt, the exdsmgr command could be unusable.
The system automatically backs up a copy of the database every night on every server. To locate the
latest database backup, run the show database_backups command on every server as shown in
the following example:
# pdsh -w glory[1-8] exdsmgr show database_backups
NOTE:
The database backup number is not unique across all servers. Also, if you delete a database backup,
the backups are renumbered.
For information on restoring a database backup, see Restoring a database backup.
Virtual hosts created by VNFS and VHTTP commands
A virtual host (vhost) is an IP address that is bound to a network interface on one of the hosts in the
HP ExDS9100 system. The Matrix software manages which server serves the IP address at any one
time. The virtual host can move to another server if the original server crashes or if specified services
terminate on the original server. This provides failover capability for network services provided by
the HP ExDS9100 system.
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