Understanding raid 0+1 – Storix Software SBAdmin Solaris System Recovery Guide User Manual
Page 47
If you select Add New, a new device will be created with a new name. The name will always start with
“hsp”, followed by a number. When adding a new device or selecting an existing device, the following
screen will appear:
Move to the Device List field and press F4 to list and select the slice or slices to add to the meta-
device. To remove the hot spare pool, move to the Create Option field and press “D”. When doing so,
the hot spare will be automatically removed from any other meta-device records it is assigned to.
When complete, press F3 or ESC to return to the
Understanding RAID 0+1
This information is provided to help you understand the association between RAID 0
and RAID 1 devices in a meta-device, and the hot spare pools used to recover from
disk failures. We provide this information in case you choose to use the Storix
recovery process to reconfigure your storage for higher performance and
availability.
A RAID 0+1 device configuration is a set of striped disks that are mirrored onto another set of striped disks.
In other words, striped mirrors. Since mirroring usually causes I/O performance degradation, this design is
typically used to get normal disk I/O performance while still having mirrored (redundant) data. A RAID 1
(mirrored) meta-device can only be created on RAID 0 (striped) meta-devices.
If the mirror contains only one RAID 0 device, then no mirroring is actually taking place (nothing to mirror
to). If you assign more than one RAID 0 to a mirror, then the data will be replicated onto each RAID 0.
Likewise, if a RAID 0 device has only one underlying device (disk slice or soft partition), then no actual
striping is taking place. SVM still allows you to create a RAID 0 with a single device, since only then can
you mirror the data. You still end up with a mirrored configuration, but with no underlying striping.
For a RAID 0+1 configuration, you need to have at least 2 stripes, each of which contain at least 2
underlying devices. Then, you create a mirrored meta-device from the 2 stripes.
Storix System Backup Administrator
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Version 8.2 Solaris System Recovery Guide