Windows Knowledge Base

[AIX.DMX]How to configure AIX devices after symm(device) configuration change?

In situations below, the disk devices will require re-configuration:
1. Converting SRDF from/to Non-SRDF device
2. Due to host failure or planned maintenance, RDF1 (R1) and RDF2 (R2) are swapped
3. Symmetrix FA ports attached to the host have sc3/sc2 bit set

Before performing above change, proceed with following procedure:
1). Stop All running EMC Agents including EMC ControlCenter, Symmetrix, Storage Device Management Agents.

2). Stop all Applications use Symmetrix devices

3). Unmount the filesystems:
# umount <Filesystem>

4). Vary off the volumegroups
# varyoffvg <VGname>

5). Skipp step5 to step7 if no powerpath installed. If PowerPath is installed, you need to de-configure PowerPath:
#powermt remove hba=all dev=all

6). Deconfigure the fscsi driver and hdisks:
# rmdev -Rdl fscsi<n>

7). Switch off the Fibre Adapter:
# rmdev -dRl fcs<n>

After complete the RDF swap or changes listed above proceed with below procedure:
1). Configure the AIX hdisks by running emc_cfgmgr:
#emc_cfgmgr
2). Enable "Fast I/O Failure", Fast I/O Failure is useful in situations where multipathing software is used. Setting the fc_err_recov attribute to fast_fail can decrease the I/O fail times because of link loss between the storage device and switch. This would support faster failover to alternate paths.
In single-path configurations, especially configurations with a single path to a paging device, the delayed_fail default setting is recommended.

To enable "Fast I/O Failure"run:
#chdev -l fscsi0 -a fc_err_recov=fast_fail
3). Enable Dynamic Tracking of Fibre Channel Devices is enabled by:
#chdev -l fscsi0 -a dyntrk=yes  
After enabled the Dynamic Tracking, the FC adapter driver detects when the Fibre Channel N_Port ID of a device changes. The FC adapter driver then reroutes traffic destined for that device to the new address while the devices are still online. Events that can cause an N_Port ID to change include moving a cable between a switch and storage device from one switch port to another, connecting two separate switches using an inter-switch link (ISL), and possibly rebooting a switch.

4).Activate the change by deactivate and activate path <n>:
#rmdev -Rl fscsi<n>
#emc_cfgmgr

5).If PowerPath is installed, configure PowerPath:
# powermt config
Ensure that all paths are working correctly:
# powermt display

6). Varyon the volumegroups:
#varyonvg <VGname>

7).Mount the filesystems:
# mount <Filesystem>

8)Start the applications
9)start Agents that was previous stopped at step1 when preparing the change.