IBM p5 550, Technical Overview And Introduction

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IBM System p5 550 and 550Q Technical Overview and Introduction
2.6.3 Integrated RAID options
A number of options are available to configure RAID on a p5-550 or p5-550Q server. The
p5-550Q can configure the optional SCSI RAID daughter card (FC 1907) that plugs directly
on the system board or with a Dual Channel Ultra320 SCSI RAID adapter (FC 1913) to drive
one 4-pack disk enclosure.
These are the different internal RAID options that can be considered:
򐂰 Install the Dual Channel SCSI RAID Enablement Card (FC 1976). Install four disk drives in
the first 4-pack DASD backplane (FC 6592). This will allow RAID 0, 5, or 10 capabilities
within a single 4-pack of DASD with one RAID controller.
򐂰 Install FC 1907. Install a second FC 6592. Install four additional disk drives in the second
4-pack DASD backplane. This will allow RAID 0, 5, or 10 capabilities across two 4-packs
of DASD with one RAID controller.
򐂰
Install FC 1907. Install the Ultra320 SCSI 4-Pack Enclosure for Disk Mirroring (FC 6593).
Install the PCI-X Dual Channel Ultra320 SCSI RAID Adapter (FC 5737). Install the SCSI
Cable, which connects the PCI Adapter to the second 4-pack DASD backplane (FC 4274).
This will allow RAID 0, 5, or 10 capabilities within each 4-pack of DASD with two RAID
controllers.
RAID implementation requires a minimum of three disk drives to form a RAID set.
2.6.4 iSCSI
iSCSI is an open, standards-based approach by which SCSI information is encapsulated
using the TCP/IP protocol to allow its transport over IP networks. It allows transfer of data
between storage and servers in block I/O formats (defined by iSCSI protocol) and thus
enables the creation of IP SANs. iSCSI allows an existing network to transfer SCSI
commands and data with full location independence and defines the rules and processes to
accomplish the communication. The iSCSI protocol is defined in iSCSI IETF draft-20. For
more information about this standard, see:
http://tools.ietf.org/html/rfc3720
Although iSCSI can be, by design, supported over any physical media that supports TCP/IP
as a transport, today's implementations are only on Gigabit Ethernet. At the physical and link
level layers, iSCSI supports Gigabit Ethernet and its frames so that systems supporting iSCSI
can be directly connected to standard Gigabit Ethernet switches and IP routers. iSCSI also
enables the access to block-level storage that resides on Fibre Channel SANs over an IP
network using iSCSI-to-Fibre Channel gateways such as storage routers and switches.
The iSCSI protocol is implemented on top of the physical and data-link layers and presents to
the operating system standard SCSI Access Method command set. It supports SCSI-3
commands and reliable delivery over IP networks. The iSCSI protocol runs on the host
Note: Because the p5-550 and p5-550Q has eight disk drive slots, if you are upgrading,
you must plan appropriately to ensure the correct handling of your RAID arrays.
RAID Capacity limitation: There are limits to the amount of disk drive capacity allowed in
a single RAID array. Using the 32-bit AIX 5L kernel, there is capacity limitation of 1 TB per
RAID array. Using the 64-bit kernel, there is a capacity limitation of 2 TB per RAID array.
For RAID adapter and RAID enablement cards, this limitation is enforced by AIX 5L when
RAID arrays are created using the PCI-X SCSI Disk Array Manager.