Storage Capacity; Expanding Storage Capacity - HP Surestore Disk Array 12h - And FC60 Service Manual

Storage Capacity

For configurations where maximum storage capacity at minimum cost is a requirement,
consider configuring the disk array in RAID 5 (using the maximum number of data drives
per parity drives) and only supplying one or two hot spare drives per disk array. Also,
purchase the lowest cost/Mbyte drive available (typically the largest capacity drives
available at the time of purchase). This configuration allows the maximum volume of
storage at the lowest cost. Disk arrays configured in this way will need to be carefully
monitored to make sure that failed disks are promptly replaced.

Expanding Storage Capacity

The disk array is designed to meet a range of capacity requirements. It can be configured
with up to six disk enclosures, and from 4 to 60 disk modules. The disk array can be
purchased with only enough capacity to meet your current storage requirements. But as
your storage needs grow, you can easily add more capacity to the Disk Array FC60.
There are several ways to increase the storage capacity of the disk array. It can be
increased by replacing existing smaller capacity disk modules with larger capacity disk
modules, by adding more disk modules to the disk enclosures, or by adding additional disk
enclosures.
The best method for expansion is to install all six disk enclosures at initial installation (full-
bus configuration). Then, install only the required capacity (number of disk modules),
leaving empty disk slots for future expansion. Additional disk modules can be installed as
the requirement for additional capacity grows. This method allows for greater flexibility in
volume group creation and does not require that the system be shut down for expansion.
Adding disk enclosures to the array after initial installation requires that the system be shut
down during the installation. All the remaining configuration expansion methods require
that the data to the array be suspended (the system shut down) to add additional disk
enclosure storage to the array.
For maximum performance, all six SCSI channels from the controller enclosure
Note
must be connected with a minimum of two disk modules per channel (disk
enclosure configured for full bus mode).
To expand a split-bus configuration (adding more disk enclosures) will require shutting the
host system down. If the initial installation included only one or two disk enclosures, then
Array Design Considerations
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