SAN Boot Implementation and Best Practices Guide ... - IBM Redbooks

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The XIV host attachment wizard successfully configured this host
Press [ENTER] to exit.
With the completion of the xiv_attach command, the xiv_devlist command can be executed
to review XIV volumes discovered, the multipath devices created for them, and the number of
paths configured. As seen in Example 4-16, multipath device mpatha been created and has
two paths to that XIV volume.
Example 4-16 Output of the xiv_devlist command
# xiv_devlist
XIV Devices
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Device Size Paths Vol Name Vol Id XIV Id XIV Host
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/dev/mapper/mpath0 51.5GB 2/2 RB_ST1L05R01_Qlogic_RH55 127 7803252 RB_xseries_01_qlogic
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Non-XIV Devices
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Device Size Paths
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As seen in Example 4-17, to get additional information about the multipathing configuration,
the multipath -ll command can be executed.
Example 4-17 Output of the multipath -ll command
# multipath -ll
mpath0 (2001738000cb4007f) dm-0 IBM,2810XIV
[size=48G][features=1 queue_if_no_path][hwhandler=0][rw]
\_ round-robin 0 [prio=2][active]
\_ 0:0:1:1 sda 8:0 [active][ready]
\_ 1:0:1:1 sdb 8:16 [active][ready]
In the above example, the output of the multipath command shows that a single mpath device
(mpath0) has been created and will distribute I/O requests across two paths (devices sda and
sdb).
For additional information about the information displayed by the multipath command and how
it relates to I/O optimization, See 4.10.2, “Linux Best Practices” on page 260.
4.9 Installation of AIX 6.1 for SAN Boot
This section provides instructions for doing a SAN Boot installation of the AIX 6.1 operating
system using Fibre Channel connectivity to XIV.
Prerequisites
To successfully SAN Boot a Windows host from XIV, a number of prerequisites need to be
met. Here is a generic list. However, your environment might have additional requirements:
► Review section 4.2, “SAN Configuration Planning” on page 203
Chapter 4. SAN Boot implementation with IBM XIV System Storage 253