ClearPath Enterprise Servers Virtual Machine for ClearPath MCP ...

Appendix A
Peripherals Information
This appendix contains restriction information about peripherals used with your system.
Using Physical Disk Drives Larger Than 100 GB
The maximum disk size supported by the MCP is 131,064,000,000 bytes. There are
different calculations to convert bytes to Gigabytes (GB). The common tendency is to
assume that 1000^3 bytes equals 1 GB. However, the precise computation of 1 GB is
1024^3 bytes. Therefore, the maximum disk size for MCP disks in Gigabytes is 122 GB,
not 131 GB.
When using disk drives that are over 100 GB in capacity, always check the size in bytes.
While Windows and most commodity storage systems compute one GB to be 1024^3
bytes, some vendors might use a different calculation.
Follow the guidelines below to configure a large disk for the MCP in a MCPvm server.
In JBOD Configuration
• Disk drives that are used for MCP logical disks have no physical size restrictions. The
Console for MCP System Editor does not allow creation of a logical disk to exceed the
MCP limit. If performance is not a concern, you can create multiple MCP logical disks
to utilize all the disk space.
• Disk drives that are greater than 122 GB (122 * 10243 = 130,996,502,528 byes)
cannot be used for VSS1 disks.
• Disk drives that are greater than 173 GB (173 * 10243 = 185,757,335,552 bytes)
cannot be used for VSS2 disks.
In a RAID Configuration
In a RAID configuration, a disk unit is a logical unit number (LUN) created from a RAID
group consisting of multiple physical disks. Each physical disk can be of any size, but the
size of a LUN must follow the guidelines below:
• For VSS disks, be sure the size of the LUN created is within the MCP limit for VSS
disks: up to 122 GB (130,996,502,528 bytes) for VSS1 and 173 GB (185,757,335,552
bytes) for VSS2.
• For MCP logical disks, there is no size limit on the LUN. Multiple MCP logical disks can
be created on the same LUN in a RAID configuration without impacting performance.
3845 8188–000 A–1