User`s guide

Document Number: MAN-0057XX-000 Version 1.0
Any node within a cascaded configuration can be set to SAFE, but it is more efficient to use the
SAFE policy at the lowest possible level within the hierarchy.
It is also possible to create a SAFE volume using one hard disk drive connected to Port 0 of the
SteelVine Storage Reference Design, although no mirroring will occur until a second hard disk
drive is connected to Port 1. With only one hard disk drive connected, the SAFE volume will be
available, although no data protection will be provided until a second hard disk drive is
connected.
SteelVine
Drive A
120 GB
Virtual SAFE
volume
Port 0
Port 1
Capacity is the same
as one hard drive.
120 GB
SteelVine
Virtual SAFE
volume
Port 0
Port 1
Capacity is the smaller
of unequal hard drives.
120 GB
Drive B
250 GB
Equal hard drives
Unequal hard drives
Drive A
120 GB
Drive B
120 GB
Figure 5 - SAFE storage policy sample configuration
SAFE33
The SAFE33 storage policy creates two virtual volumes; one SAFE volume and one BIG
volume, and should be used when you need the high reliability for some of your data (with the
added overhead of mirroring) but you don’t need high reliability for the remainder of your data.
SAFE33 reduces the cost of additional hard drives in operations where non-critical data could be
lost without severe consequences.
SAFE33 uses a SAFE volume that is mirrored across two hard drives to protect your critical data
in the event a hard drive failure. If one drive fails the SAFE volume is retrievable although the
BIG volume is not. When you replace the failed drive, the SAFE volume is automatically rebuilt
on to the replacement drive.
For example, if you are using a video editing application that stores the primary source data and
also uses some temporary storage for editing, you need protected storage that is offered by SAFE
for the primary source data, but you do not need protected storage for the temporary data.
Therefore, the combination of SAFE and BIG would be the most efficient utilization of your
available storage capacity. If either hard drive fails the primary data stored on the SAFE volume
would still be available whereas the temporary data stored on the BIG volume would be lost.
The size of the SAFE volume of a SAFE33 policy will be one-third of the size of one hard drive
(if they are equal) or one-third of the size of the smaller (if they are not equal.
) The size of the
BIG volume will be the combination of all remaining capacities.
57XX-Series SteelVine Manager User's Guide
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