HP StoreEver MSL6480 Tape Library - Manual (Page 16)

3 Installing advanced path failover
To successfully install advanced path failover, complete the following:
•
Prepare the SAN. See “Preparing the SAN” (page 16) .
•
Prepare the library. See “Preparing the library” (page 16) .
•
Prepare the host. See “Preparing the host” (page 17) .
Preparing the SAN
To prepare the SAN, review the following:
•
“Minimize host access” (page 16)
•
“Configure redundant connections” (page 16) .
•
“Review the SAN design guidelines” (page 16)
•
Verify that the switch prerequisites are met. See “Preparing the switches and hosts for failover”
(page 18) .
Minimize host access
Advanced path failover is supported for a maximum of 32 hosts connected to each tape drive or
tape library. Each host should have two to four ports for a total of 64 to 128 connections to each
tape drive or tape library.
Connecting more than 32 hosts may cause performance degradation if extra hosts are attempting
to access the drives or library while another host is using the device.
Use switch zoning or Secure Manager to configure the SAN or library so that only hosts that need
to access the devices are able to connect.
Configure redundant connections
Each tape drive in the library has two ports. For best results the drives should be connected to two
different SANs, with all of the first ports connected to one SAN and all of the second ports connected
to another SAN. The total number of SAN switch ports required for connecting the library is twice
the number of tape drives installed in the library.
If both ports for a tape drive are connected to the same switch, fault tolerance is reduced as a
single switch failure will cause loss of connectivity. If only one switch is available, that switch must
be zoned to create two logical SANs.
Review the SAN design guidelines
The general SAN design guidelines for tape are documented at: http://www.hp.com/go/ebs .
Preparing the library
Advanced path failover is a licensed feature with Control Path Failover and Data Path Failover
licensed separately. Licenses for all failover solutions are also available as a high-availability
bundle. Control Path Failover provides path fault tolerance for the robot controller and Data Path
Failover provides fault tolerance for the tape drive data path. Each feature is licensed once for
each tape library and then enabled separately for every partition and tape drive. The settings may
be different for different partitions and drives depending on the user requirements.
When advanced path failover is enabled for either the control path or the data path, the library
partition and/or tape drives with advanced path failover enabled can only be used by hosts with
the advanced path failover driver installed. If the tape drive or tape library detects that advanced
path failover is enabled and a request to access the media or move media is received from a host
16 Installing advanced path failover