VERITAS Storage Foundation 4.1 Cross-Platform Data Sharing Administrator's Guide

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Cross-Platform Transfer
A
This appendix contains notes on considerations for data transfer between operating system
platforms with different inherent characteristics.
Alignment Value and Block Size
On the AIX, Linux and Solaris operating systems, an alignment value of 1 is equivalent to a block
size of 512 bytes. On the HP-UX operating system, it is equivalent to a block size of 1024 bytes.
The block size on HP-UX is different from that on other supported platforms. Output from
commands such as vxdisk and vxprint looks different on HP-UX for the same disk group if
the -b option is not specified.
Default Activation of Shared Disk Groups
This is a local in-kernel policy that differs between platforms. This means that, regardless of the
platform on which the disk group was created, the importing platform will have platform-specific
behavior with respect to activation of shared disk groups. Specifically, with the exception of
HP-UX, importing a shared disk group will result in the volumes being active and enabled for
shared-write. In the case of HP-UX, the shared volumes will be inactive and require other actions to
activate them for shared-write operations.
Disk Group Alignment and Encapsulated Disks
On the Solaris OS, all native file systems are cylinder aligned. Encapsulating such a disk results in
subdisks that are also cylinder aligned. Such alignment will normally not be 8K aligned, but it will
be 1K aligned. For the encapsulation process, there is no flexibility as to where on the disk the
subdisks must be since the data location is predefined. If an alignment conflict occurs, user
intervention is required. If the disk group alignment is 8K this operation will probably fail because
this would require the cylinder to be an even number of 8K blocks in size.