Iscsi Configuration On The Snapserver - Overland Storage SnapServer Administrator's Manual

SnapServer 7.0 Administrator's Guide
iSCSI Configuration for Mac
GuardianOS supports globalSAN 4.1 and the SmallTree abcSAN iSCSI initiator for use
with Mac OS 10.5 and later. Download the initiator software from the
and follow the installation instructions.
NOTE: If iSCSI is used on a SnapServer with more than one Ethernet port, Mac OS X iSCSI

iSCSI Configuration on the SnapServer

iSCSI disks are created on the Storage > iSCSI page of the Web Management Interface.
Before setting up iSCSI disks on your SnapServer, carefully review the following
information.
Basic Components of an iSCSI Network
iSCSI is used to facilitate data transfers over intranets and to manage storage over long
distances. A basic iSCSI network has two types of devices:
• iSCSI initiators, either software or hardware, resident on hosts (usually servers), that
start communications by issuing commands; and
• SCSI Targets, resident on storage devices, that respond to the initiators' requests for
data.
The interaction between the initiator and target mandates a server-client model where the
initiator and the target communicate with each other using the SCSI command and data
set encapsulated over TCP/IP. Overland Storage is one of the first to embed iSCSI target
support in its SnapServers.
Isolate iSCSI Disks from Other Resources for Backup Purposes
It is important to isolate iSCSI disks from other resources on the SnapServer for two
reasons:
• The filesystem of an iSCSI disk differs fundamentally from the SnapServer's native
filesystem.
• iSCSI disks are managed from client software rather than the SnapServer's Web
Management Interface.
For ease of management and particularly for data integrity and backup purposes, either
dedicate the entire SnapServer to iSCSI disks, or if the server is to be used with other
shared resources, place the iSCSI disk and the other shared resources on separate volumes.
• Back up an iSCSI Disk from the Client, not the SnapServer – An iSCSI disk is
not accessible from a share and thus cannot be backed up from the SnapServer. The
disk can, however, be backed up from the client machine from which the iSCSI disk is
managed.
NOTE: While some third-party, agent-based backup packages could technically back up an
10400317-001 10/2011
clients can encounter connectivity issues if multiple ports are connected to one or more
networks. To avoid these issues, configure the server from Network > TCP/IP to enable
and connect only one standalone interface or one bonded pair (Load Balance, Failover,
etc.) to a single network.
iSCSI disk on the SnapServer, the result would be inconsistent or corrupted backup
data if any clients are connected during the operation. Only the client can maintain the
filesystem embedded on the iSCSI disk in the consistent state that is required for data
integrity.
©2010-11 Overland Storage, Inc.
6 – Other Storage Options
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