Drive Maintenance Policy; Host Attachment Overview - IBM DS8900F Introduction And Planning Manual

• 2.5-inch Flash Tier 1 drives with FDE
– 3.84 TB
• 2.5-inch Flash Tier 2 drives with FDE
– 1.92 TB
– 7.68 TB
– 15.36 TB
Note: Intermix of high performance drives (Flash Tier 0) with high capacity drives (Flash Tier 1 or Flash
Tier 2) is not supported within an enclosure pair.

Drive maintenance policy

A minimum of two spare drives are allocated in a device adapter loop.
Internal maintenance functions continuously monitor and report (by using the call home feature) to IBM
when the number of drives in a spare pool reaches a preset threshold. This design ensures continuous
availability of devices while it protects data and minimizing any service disruptions.
It is not recommended to replace a drive unless an event is generated indicating that service is needed.

Host attachment overview

The storage system provides various host attachments so that you can consolidate storage capacity and
workloads for open-systems hosts and IBM Z .
The storage system provides extensive connectivity using Fibre Channel adapters across a broad range of
server environments.
Host adapter intermix support
A maximum of four host adapters per I/O enclosure is supported, including 4-port 16 Gbps adapters and
4-port 32 Gbps adapters.
Models 993, 994, and 996
The following table shows the host adapter plug order.
Table 13. Plug order for 4-port HA slots for two and four I/O enclosures
I/O enclosures
For two I/O enclosures (all models)
Top I/O enclosure 1
Bottom I/O
enclosure 3
Top I/O enclosure 2
Bottom I/O
enclosure 4
For four I/O enclosures (model 996)
Top I/O enclosure 1
Bottom I/O
enclosure 3
Top I/O enclosure 2
Bottom I/O
enclosure 4
28 IBM DS8900F: DS8900F Introduction and Planning Guide
C1 C2
3 7
2 8
7 15
5 13
4 12
2 10
Slot number
C3 C4
1
4
3
1
8
6
C5 C6
5
6
11
9
16
14