Oracle ZFS Storage Appliance: How to avoid mis-alignment when using ZFS on LDOM clients (Doc ID 2157669.1)

Last updated on JUNE 12, 2017

Applies to:

Oracle ZFS Storage ZS4-4 - Version All Versions to All Versions [Release All Releases]
Oracle ZFS Storage ZS3-2 - Version All Versions to All Versions [Release All Releases]
Sun ZFS Storage 7320 - Version All Versions to All Versions [Release All Releases]
Sun ZFS Storage 7420 - Version All Versions to All Versions [Release All Releases]
Sun ZFS Storage 7120 - Version All Versions to All Versions [Release All Releases]
7000 Appliance OS (Fishworks)

Goal

This document provides the steps required to ensure there is no mis-alignment when LDOMs use ZFS on top of ZFSSA LUNs.

The procedure overview is as follows :

  1.  ZFSSA : Create a LUN with a volblocksize of 8KB (default)
  2.  Control domain : Make the LUN recognized
  3.  Control domain : Use format to configure a simple disk layout
  4.  Control domain : Assign the c0txd0s2 partition to an LDOM
  5.  LDOM : Login to the LDOM and list the disks via format
  6.  LDOM : Retrieve the vdc instance of the device(s) you want to use for a ZFS pool
  7.  LDOM : Edit the /platform/sun4v/kernel/drv/vdc.conf
  8.  LDOM : Reboot the LDOM
  9.  LDOM : Create the pool
  10.  LDOM : Create a ZFS filesystem and confirm correct filesystem operation

 

Misalignment can be expensive in term of extra IOs done on the ZFSSA side. For more details, see http://blogs.oracle.com/dlutz/entry/partition_alignment_guidelines_for_unified.

Since Solaris 11.1.11.4.0, it becomes a little easier to remove mis-alignment issues when LDOMs use ZFS on top of LUNS exported by a ZFSSA.

The enhancement comes from : ER 15824910 - Add support to configure vdisk physical block size in vdc.conf

Previously, the workaround was to create the zpool on the control domain with the original ssd-config-list entry for ZFSSA in ssd.conf and export zfs volume dataset to the guest domain.

 

Solution

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