Sun Microsystems Sun StorEdge T3, Installation, Operation And Service Manual

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2-42 Sun StorEdge T3 Disk Tray Installation, Operation, and Service Manual • July 2000
Note – There are two commands available to determine the drive volume capacity
of the Sun StorEdge T3 disk tray. Within the disk tray, the
vol
command is used to
display the raw volume capacity. Within the Solaris environment, the
format(1M)
utility (among others) can be used to display the capacity of a newly created volume.
When comparing volume capacities between the internal Sun StorEdge T3 disk tray
vol
command and the Solaris environment
format(1M)
command, the Solaris
format(1M)
command reports a smaller volume capacity. This is due to the Solaris
environment reporting volume sizes using 1,024 bytes per Kbyte capacities.
For example, using the Sun StorEdge T3 disk tray
vol
command, a 4-drive 18-Gbyte
RAID 0 volume would report a 71.6 Gbyte capacity within the disk tray. This is
calculated as follows:
139857920 blks * 512 bytes/blk * 1 Gbyte/1000
3
= 71.6 Gbytes
The
format(1M)
command in the Solaris environment reports a 66.69 Gbyte
capacity for the same volume using 1,024 bytes per Kbyte, calculated as follows:
139857920 blks * 512 bytes/blk * 1 Gbyte/1024
3
= 66.69 Gbytes
There is no loss of actual disk capacity.
2.12.3 Creating Soft Partitions on the Data Host
The Sun StorEdge T3 disk tray’s native volume management can support a
maximum of two volumes or logical units (LUNs) per disk tray unit. This can result
in very large volumes (128 Gbytes in a configuration of single 7+1 RAID 5 LUN plus
hot spare, with 18 Gbyte drives). Some applications cannot use such large volumes
effectively. There are two solutions, which can be used separately or in combination.
■
First, use the partitioning utility available on the data host’s operating system. In
the Solaris environment, this is the
format
utility, which can create up to seven
distinct partitions per volume. Note that in the case of the configuration described
above, if each partition is equal in size, this will result in 18 Gbyte partitions,
which still may be too large to be used efficiently by legacy applications.
■
Second, you can use third-party software on the host to create as many partitions
as desired from a given volume. In the Solaris environment, VERITAS Volume
Manager can be used for this purpose.
For information on using the
format
utility, refer to the
format(1M)
man page. For
more information on third-party software such as VERITAS Volume Manager, refer
to the documentation for that product.