Serveraid Considerations; Hardware Considerations; Controller Considerations; Array Or Logical Drive Considerations - IBM Netfinity ServeRAID-4H Ultra160 User Reference

ServeRAID considerations

It is important to understand the following ServeRAID considerations before you set
up your high-availability cluster solution.
Note: The following ServeRAID considerations are for the Microsoft Cluster

Hardware considerations

v The SCSI-2 Fast/Wide Enhanced Repeater Card is required for configurations
v Do not connect nondisk devices, such as CD-ROM drives, to shared channels.
v You must cable the SCSI channels in a controller pair so that the controllers
v You must connect all disks that will be shared to the shared channels. This
v All shared physical drives must be part of a logical drive or defined as a hot

Controller considerations

v Each ServeRAID controller must have a unique controller name assigned.
v Do not attempt to change the controller name on both ServeRAID controllers in a
v Each ServeRAID controller, and controller pair, must have a different SCSI
v You must set the stripe-unit size of each ServeRAID controller in a pair to the
v You cannot share hot-spare drives between controllers in a cluster pairing. If you
v Physical drives that are configured by one controller in the pair must appear as

Array or logical drive considerations

v The ServeRAID controller does not allow the failover of RAID level-5 logical
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IBM Netfinity User's Reference: ServeRAID
Solution using Windows NT and Windows 2000. For similar considerations
for the Novell IntranetWare Cluster Solution, refer to the Vinca High
Availability for NetWare manual.
using the IBM Enterprise Expansion Enclosure (Model 3518) or the IBM Model
3519 Rack Expansion Enclosure. The previous version of the SCSI-2 Fast/Wide
Repeater is not supported in these configurations. For information on the latest
version of the SCSI Fast/Wide Enhanced Repeater Card, contact your IBM
reseller or marketing representative.
These devices will be accessible to both servers, and conflicts might arise.
share the same channels.
includes hot-spare drives, as well as data drives.
spare to one or the other servers. You must remove all other physical drives from
the shared disk enclosure to ensure proper operation.
pair at the same time. Doing so can cause a problem, such as a server lock-up.
initiator ID assigned to the shared channels. For example, set one server, Server
A, to ID 6, and set the other server, Server B, to ID 7. The setup instructions
describe this in more detail.
same value (8 KB, 16 KB, 32 KB, or 64 KB).
want hot-spare protection, each ServeRAID controller must have a hot-spare
drive defined. You must connect hot-spare drives only to shared channels. This is
in case the hot-spare drive replaces a failed shared drive. Both servers must be
able to access the drive in case a failover occurs after the shared drive fails.
ready drives to the other controller in the pair. Be sure to verify this consideration
when you add drives. Restart both servers, or scan for new devices using the
ServeRAID Manager program on both servers, to make sure the added physical
drives appear as ready drives on both servers before creating logical drives.
drives that are in a critical state; that is, a drive in a RAID level-5 array that has
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-4H Ultra160 SCSI Controller