Background
Let’s face it – doing this type of a migration for AIX would be a breeze. However, SLES on IBM POWER plays by a different set of rules. For anyone out there running a similar configuration, I thought it would be a good idea to post the procedure now that we’ve figured it out.
Environment
- Existing storage controller: IBM XIV
- New storage controller: IBM FS7200, exploring the “SVC” features
- Operating System: SLES 12 SP4
- Hardware: IBM POWER
Problem
The XIV LUNs are first moved behind the V7K. This causes the LUN uid number to change. Since the LUN uid is hard coded in the initramfs boot image, the OS will not boot. Incidently, there were no issues with the LUN uid number changing on any LUNs other than the OS LUN.
Solution
- The host must be booted into System Rescue mode from the SLES 12 SP4 install DVD.
- This provides the capability to run mkinitrd which re-creates initramfs using the new LUN uid number.
- Then the SMS boot list must be updated to use the new LUN
Procedure
1. Shutdown host
2. Storage admin maps all XIV LUNs through/behind the new storage unit
-
- Zone the XIV to the V7K and create a host object on the XIV with the V7K’s FC WWPNs.
- Zone the hosts to the V7K and create host objects on the V7K with the hosts’ FC WWPNs.
- On the XIV, unmap the LUNs from the host.
- On the XIV, map those LUNs to the V7K.
- On the V7K, detect mdisks.
- On the V7K, create image-mode volumes using those mdisks.
- On the V7K, map these image-mode volumes to the host.
- Bring up the host and do anything you need to do there to get the volumes online/tested/etc.
- When ready, migrate the data from the image-mode mdisks to the internal arrays. Host I/O can be occurring during this.
- When the data has been removed from the image-mode mdisks, unmap them from the V7K.
3. Lpar is booted into “System Rescue” mode from a virtual install DVD (iso image)
-
- mount install dvd to lpar from vio server
- boot lpar to sms – boot from dvd
- select “Rescue System”
- login as root – no password
4. Activate multipathing
multipath -v4 multipath -ll
5. Activate volume groups
vgchange -ay
6. Mount all OS filesystems from the remapped LUN
Note: The OS volume group filesystem layout must be recorded prior to start of migration
The /mnt/sysimage mount point is an arbitrary name but must match what is used by the chroot command below
mkdir /mnt/sysimage mount /dev/system_vg/root_lv /mnt/sysimage mount /dev/system_vg/home_lv /mnt/sysimage/home mount /dev/system_vg/opt_lv /mnt/sysimage/opt mount /dev/system_vg/syslogs_lv /mnt/sysimage/syslogs mount /dev/system_vg/tmp_lv /mnt/sysimage/tmp mount /dev/system_vg/usr_lv /mnt/sysimage/usr mount /dev/system_vg/var_lv /mnt/sysimage/var mount -o bind /proc /mnt/sysimage/proc mount -o bind /sys /mnt/sysimage/sys mount -o bind /dev /mnt/sysimage/dev
7. Get /boot disk identifier (part-2) and mount
ls /dev/mapper | grep part-2 mount /dev/mapper/360050764008501588000000000000007-part2 /mnt/sysimage/boot
8. Run chroot pointing to filesystems mounted from new OS LUN
chroot /mnt/sysimage
9. Run mkinitrd command which rebuilds initramfs (used during the boot process)
mkinitrd
10. Reboot and update SMS profile to point to the new LUN as default
exit reboot
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*Note: The boolist must be re-created in SMS
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Select Boot Options ------------------------------------------------------------------------------- Navigation Keys: X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:5 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Multiboot 1. Select Install/Boot Device 2. Configure Boot Device Order 3. Multiboot Startup <OFF> 4. SAN Zoning Support ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:2 .------------------. | PLEASE WAIT.... | `------------------' PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Configure Boot Device Order 1. Select 1st Boot Device 2. Select 2nd Boot Device 3. Select 3rd Boot Device 4. Select 4th Boot Device 5. Select 5th Boot Device 6. Display Current Setting 7. Restore Default Setting ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:1 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Device Type 1. Tape 2. CD/DVD 3. Hard Drive 4. Network 5. None 6. List All Devices ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:3 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Media Type 1. SCSI 2. SAN 3. SAS 4. SATA 5. USB 6. NVMe 7. None 8. List All Devices ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:2 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Media Adapter 1. U9009.22A.7824900-V145-C3-T1 /vdevice/vfc-client@30000003 2. U9009.22A.7824900-V145-C4-T1 /vdevice/vfc-client@30000004 3. None 4. List all devices ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:1 scan /vdevice/vfc-client@30000003 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Task U9009.22A.7824900-V145-C3-T1 /vdevice/vfc-client@30000003 1. Specify a boot device using WWPN and LUN 2. Scan for available boot devices ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:2 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Scan options U9009.22A.7824900-V145-C3-T1 /vdevice/vfc-client@30000003 Number of devices available for scan: 6 Specify a range for the scan 1. Start value for the scan range : 1 2. End value for the scan range : 6 3. Scan -> Number of devices selected for scan : 6 -> Approximate time for scan : 1 Min(s) 12 Sec(s) ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:3 check /vdevice/vfc-client@30000003/disk@500507680b35756f,0000000000000000 check /vdevice/vfc-client@30000003/disk@500507680b35756f,0001000000000000 check /vdevice/vfc-client@30000003/disk@500507680b35756f,0002000000000000 check /vdevice/vfc-client@30000003/disk@500507680b35756e,0000000000000000 check /vdevice/vfc-client@30000003/disk@500507680b35756e,0001000000000000 check /vdevice/vfc-client@30000003/disk@500507680b35756e,0002000000000000 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Device Device Current Device Number Position Name 1. - 128 GB FC Harddisk, part=1 () ( loc=U9009.22A.7824900-V145-C3-T1-W500507680b35756f-L0002000000000000 ) 2. - 128 GB FC Harddisk, part=1 () ( loc=U9009.22A.7824900-V145-C3-T1-W500507680b35756e-L0002000000000000 ) 3. None ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:1 PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Select Task 128 GB FC Harddisk, part=1 () ( loc=U9009.22A.7824900-V145-C3-T1-W500507680b35756f-L0002000000000000 ) 1. Information 2. Set Boot Sequence: Configure as 1st Boot Device ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:2 .------------------. | PLEASE WAIT.... | `------------------' PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Current Boot Sequence (1) 128 GB FC Harddisk, part=1 () ( loc=U9009.22A.7824900-V145-C3-T1-W500507680b35756f-L0002000000000000 ) (2) None (3) None (4) None (5) None ------------------------------------------------------------------------------- Navigation keys: M = return to Main Menu ESC key = return to previous screen X = eXit System Management Services ------------------------------------------------------------------------------- Type menu item number and press Enter or select Navigation key:X PowerPC Firmware Version FW910.11 (VL910_115) SMS (c) Copyright IBM Corp. 2000,2017 All rights reserved. ------------------------------------------------------------------------------- Are you sure you want to exit System Management Services? (1) Yes (2) No
11. Login to Lpar and verify filesystems
12. Issue shutdown/activate from OS to verify successful boot from default LUN
