User Guide

16 Novell Storage Services Administration Guide
Novell Storage Services Administration Guide
103-000141-001
August 30, 2001
Novell Confidential
Manual 99a38 July 17, 2001
 You can only mirror partitions. However, you might want to mirror an
entire storage pool. Because you can have only one storage pool on a
partition, the only way to mirror that storage pool is to mirror all of the
partitions the pool resides on.
 To mirror partitions, you need to select an option that makes the partitions
compatible for mirroring when you create them—you cannot change that
mirroring option after you create a partition. You can mirror to an existing
group or create a new mirror group for the partition. You cannot combine
mirror groups (existing groups with multiple mirrored partitions).
 Mirrored partitions must have compatible data area size. This means the
new partition must be at least the same size or slightly larger than the
other partitions in the group. For example, the physical size (combined
data and hot fix size) must be at least 100 KB bigger, but no more than
120 MB bigger than the data size of the existing partitions in the mirror
group.
The file system adjusts the Hot Fix size to the legal ranges in order to
make the data area identical to the other partitions in the mirror group.
 Mirrored partitions must have the same sharable for clustering status.
 The partitions you add to a group cannot be part of an existing group—
they must be individual mirrored objects.
Stripe Data Across Storage Devices (RAID)
NSS lets you create an additional storage device by striping data across
multiple disk drives on your system. This option, called RAID, is a software
configuration that emulates an actual hardware RAID 0 system. This RAID
configuration occurs at the software level instead of using a RAID machine.
You set up a RAID device by obtaining space from all your physical storage
devices then putting segments on the combined space. A RAID segment is the
amount of space you obtain from each storage device. You can have up to
eight segments on a RAID device. The file system places data on the RAID
disks sequentially. This is called disk striping. The RAID stripe size is the
amount of data the file system places on a disk before moving to the next disk.
You can use the software RAID 0 on both logical and traditional volumes.