Mount a CD in AIX

# mount -v cdrfs -o ro /dev/cd0 /cd

Or we can follow the process:

# startsrc -s cdromd
# lssrc -s cdromd
# cdmount cd0
# cdcheck cd0
# cdeject cd0
# cdumount cd0

Recovery from MPIO Failure

If you have set up disks from 2 VIO servers using MPIO to an AIX LPAR, then you need to make some changes to your hdisks.

You must make sure the hcheck_interval and hcheck_mode are set correctly:

Example for default hdisk0 settings:

# lsattr -El hdisk0
PCM             PCM/friend/vscsi                 Path Control Module        False
algorithm       fail_over                        Algorithm                  True
hcheck_cmd      test_unit_rdy                    Health Check Command       True
hcheck_interval 0                                Health Check Interval      True
hcheck_mode     nonactive                        Health Check Mode          True
max_transfer    0x40000                          Maximum TRANSFER Size      True
pvid            00cd1e7cb226343b0000000000000000 Physical volume identifier False
queue_depth     3                                Queue DEPTH                True
reserve_policy  no_reserve                       Reserve Policy             True

IBM recommends a value of 60 for check_interval and hcheck_mode should be set to "nonactive".

To change these values (if necessary):

# chdev -l hdisk0 -a hcheck_interval=60 -P

# chdev -l hdisk0 -a hcheck_mode=nonactive -P

Now, you would need to reboot for automatic path recovery to take effect.

If you did not set the check_interval and hcheck_mode as described above or did not reboot, then after a failed path, you would see the following even after the path is back online:

# lspath
Enabled hdisk0 vscsi0
Failed  hdisk0 vscsi1

To fix this, you would need to execute the following commands:

# chpath -l hdisk0 -p vscsi1 -s disable

# chpath -l hdisk0 -p vscsi1 -s enable

Now, check the status again:

# lspath
Enabled hdisk0 vscsi0
Enabled hdisk0 vscsi1

Dynamically Removing an I/O Slot

To remove a dynamically allocated I/O slot (must be a desired component) from a partition on a P-series IBM server partition:

1) Find the slot you wish to remove from the partition:

# lsslot -c slot
# Slot Description Device(s)
U1.5-P2/Z2 Logical I/O Slot pci15 scsi2
U1.9-P1-I8 Logical I/O Slot pci13 ent0
U1.9-P1-I10 Logical I/O Slot pci14 scsi0 scsi1
In our case, it is pci14.

2) Delete the PCI adapter and all of its children in AIX before removal:

# rmdev -l pci14 -d -R
cd0 deleted
rmt0 deleted
scsi0 deleted
scsi1 deleted
pci14 deleted

3) Now, you can remove the PCI I/O slot device using the HMC:

a) Log in to the HMC

b) Select "Server and Partition", and then "Server Management"

c) Select the appropriate server and then the appropriate partition

d) Right click on the partition name, and then on "Dynamic Logical Partitioning"

e) In the menu, select "Adapters"

f) In the newly created popup, select the task "Remove resource from this partition"

g) Select the appropriate adapter from the list (only desired one will appear)

h) Select the "OK" button

i) You should have a popup window which tells you if it was successful.