The following I found in the Novell Docuemntation:

Nested RAIDs (also referred to as hybrid RAIDs by the Storage Networking
Industry Association) are multi-level RAIDs built from basic RAID levels.
In general, nested RAID devices for Linux are not supported because of
how the md driver stores key information. The RAID information for the
second RAID overwrites the first. If you attempt to nest the basic RAIDs,
it appears to work, but the configuration is lost upon reboot.

The mdadm management tool supports only one complex RAID level, called
RAID10. However, the RAID10 option is not formed by nesting basic RAIDs.
It is similar to a RAID 1+0 but with striping integrated into the array.
Data is not mirrored to a second disk. Instead, the algorithm uses dual-
rotating striping to disks in the array. The MD plug-in to EVMS does not
support the md drivers RAID10 option. To learn more about the RAID10
option for mdadm, see the mdadm man page.

NOTE:The Novell Storage Services (NSS) file system for Linux supports
software RAIDs 0, 1, 5, and nested RAIDs 10 and 15. NSS interfaces with
EVMS APIs to manage devices on Linux, but also adds code that allows
nesting on Linux. NSS is available in Novell Open Enterprise Server. For
information, visit the Novell Open Enterprise Server Web site.

QUESTION: Can we combine RAID'S 1 and 5 on OES Linux Server, with the
Novell Storage Services (NSS), which we use. Or is this artical
saying, "NO", because it would be considered nested. So, we should
use RAID 10 or RAID 15?

Thank You
Susan Evans
Haywood County Schools