Scale Up Configuration

Install the SAP HANA Scale Up system on both compute 1 and compute 2.

Use the same instance SID for both installations.
Use the same <sid>adm user password on both systems.
Ensure the data and log volumes are mounted to the same location.

Configure the data, catalog, and log streaming backup location on both SAP HANA systems.

If using backint ensure that both systems have access to the same backup set in the ISV.
If using a filesystem based backup ensure that either a shared filesystem or NFS mount point is used, ensure that any subfolders in the backup location are owned by the <sid>adm user.

Stop the SAP HANA instances on all systems by running the following command on each of them:


/usr/sap/hostctrl/exe/sapcontrol -nr <instance number> -function Stop

4. Wait until the instances have stopped on each system by using the following command:


/usr/sap/hostctrl/exe/sapcontrol -nr <instance number> -function GetProcessList

5. Unmount, Disconnect and Delete any SAP HANA Log and Data volumes from compute 2 (and/or 3). The only remaining data and log volumes should be those from Compute 1.

6. Connect the arrays using synchronous replication, optionally add a third array for asynchronous replication.

7. On Array 1, In Protection->ActiveCluster Create a new POD, add the volumes to the POD and then add in Array 2 to stretch the pod. At this point the volumes will begin initial synchronization. Once Initial synchronization is complete both Arrays should as online.

8. At this point the volumes are online on both arrays, connect the host for compute 1 and compute 2 to the volumes in the POD on array 1 and array 2.

9. Ensure that the correct configuration for ActiveCluster DM-Multipath has been done on all nodes - find the configuration in the ActiveCluster Requirements and Best Practices.

10. If required, set the preferred paths for each host in FlashArray.

11. Start the SAP HANA Instance on Compute 1 using the following command:


/usr/sap/hostctrl/exe/sapcontrol -nr <instance number> -function Stop

12. If required for third site availability add the POD to a Protection Group with Array 3 as the target.

Failover Process

In the event of losing a single array (array 1 or 2) there will be no impact on application availability as failover is transparent.

In the event of losing the compute upon which the SAP HANA instance is running at that point in time - the below process will need to be followed to bring the SAP HANA instance up on alternative compute.

Note:

If restoring service to compute 1 or compute 2 (systems attached to the synchronous replication volumes) then the volumes will already exist on the array and should be connected to the relevant host. If the SAP HANA instance is being failed over to a third site replicated to using asynchronous replication then the snapshots must first be restored to volumes and connected to the relevant host(s).

Step 1. Ensure the log and data volumes are not mounted anywhere else.

Use the "umount" command in a terminal or ssh connection to unmount any mounted volumes.


umount /hana/data
umount /hana/log

Step 2. Mount the log and data volume to the system being failed over to. This assumes the volumes were already connected previously.

To identify the volumes use the multipath -ll command:


multipath -ll

3624a93701b16eddfb96a4c3800011c31 dm-5 PURE,FlashArray 
size=1.0T features='0' hwhandler='1 alua' wp=rw
|-+- policy='queue-length 0' prio=50 status=active
| |- 6:0:5:2  sdp  8:240  active ready running
| |- 6:0:3:2  sdl  8:176  active ready running
| |- 6:0:9:2  sdx  65:112 active ready running
| |- 6:0:7:2  sdt  65:48  active ready running
`-+- policy='queue-length 0' prio=10 status=enabled
  |- 6:0:0:2  sdj  8:144  active ready running
  |- 6:0:4:2  sdn  8:208  active ready running
  |- 6:0:6:2  sdr  65:16  active ready running
  |- 6:0:8:2  sdv  65:80  active ready running
3624a93701b16eddfb96a4c3800011c30 dm-6 PURE,FlashArray
size=5.0T features='0' hwhandler='1 alua' wp=rw
|-+- policy='queue-length 0' prio=50 status=active
| |- 6:0:7:1  sds  65:32  active ready running
| |- 6:0:3:1  sdk  8:160  active ready running
| |- 6:0:5:1  sdo  8:224  active ready running
| |- 6:0:9:1  sdw  65:96  active ready running
`-+- policy='queue-length 0' prio=10 status=enabled
  |- 6:0:8:1  sdu  65:64  active ready running
  |- 6:0:0:1  sdi  8:128  active ready running
  |- 6:0:4:1  sdm  8:192  active ready running
  |- 6:0:6:1  sdq  65:0   active ready running

Using the above wwids (the text at the beginning of each device starting with 3624a9370) the data and log volume can be mounted to the standby SAP HANA system:


mount /dev/mapper/3624a93701b16eddfb96a4c3800011c30 /hana/data
mount/dev/mapper/3624a93701b16eddfb96a4c3800011c31 /hana/log

Verify the volumes are mounted correctly by using the "df" command:


df -h

Filesystem                                           Size  Used Avail Use% Mounted on
devtmpfs                                             1.5T     0  1.5T   0% /dev
tmpfs                                                2.2T   32K  2.2T   1% /dev/shm
tmpfs                                                1.5T   13M  1.5T   1% /run
tmpfs                                                1.5T     0  1.5T   0% /sys/fs/cgroup
/dev/mapper/3624a9370c49a4cb0e2944f4400038775-part2   60G   17G   44G  28% /
/dev/mapper/3624a9370c49a4cb0e2944f4400031d31        512G   43G  470G   9% /hana/shared
fileserver.puredoes.local:/mnt/nfs/HANA_Backup       1.0T  153G  872G  15% /hana/backup
tmpfs                                                290G   20K  290G   1% /run/user/469
tmpfs                                                290G     0  290G   0% /run/user/468
tmpfs                                                290G     0  290G   0% /run/user/1001
tmpfs                                                290G     0  290G   0% /run/user/0
/dev/mapper/3624a93701b16eddfb96a4c3800011c30        5.0T  625G  4.4T  13% /hana/data
/dev/mapper/3624a93701b16eddfb96a4c3800011c31        1.0T  362G  663G  36% /hana/log

Step 3. As the <sid>adm user use the hdbnsutil to change the system name.


hdbnsutil -convertTopology


 nameserver sarah:30001 not responding.
Opening persistence ...
sh1adm: no process found
hdbrsutil: no process found
run as transaction master
converting topology from cloned instance...
- keeping instance 00
- changing host hannah to sarah
done.

Step 4. Start the SAP HANA system.

Use the sapcontrol utility to start the SAP HANA system:


/usr/sap/hostctrl/exe/sapcontrol -nr <instance number> -function Start

A successful start request will respond as follows:


09.07.2020 08:46:57
Start
OK

To check on the status of the startup process for SAP HANA use the sapcontrol command with the GetProcessList function:


 /usr/sap/hostctrl/exe/sapcontrol -nr <instance number> -function GetProcessList

Once each process has been started, each should be shown as "GREEN".


09.07.2020 08:47:39
GetProcessList
OK
name, description, dispstatus, textstatus, starttime, elapsedtime, pid
hdbdaemon, HDB Daemon, GREEN, Running, 2020 07 09 08:46:58, 0:00:41, 102275
hdbcompileserver, HDB Compileserver, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102544
hdbindexserver, HDB Indexserver-SH1, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102599
hdbnameserver, HDB Nameserver, GREEN, Running, 2020 07 09 08:46:58, 0:00:41, 102293
hdbpreprocessor, HDB Preprocessor, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102547
hdbwebdispatcher, HDB Web Dispatcher, GREEN, Running, 2020 07 09 08:47:21, 0:00:18, 114411
hdbindexserver, HDB Indexserver-SH2, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102602
hdbindexserver, HDB Indexserver-SH3, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102605
hdbindexserver, HDB Indexserver-SH4, GREEN, Running, 2020 07 09 08:47:05, 0:00:34, 102608