Hello out there,
this first Blog entry in our techie Blog covers an implementation sample of TSM 6.2 with the db2 backend (introduced with TSM 6.1) on AIX 6.1 that is asynchronously replicated to a second AIX 6.1 system via IBMs Softek replication software.
In our small computer room here in Auckland (New Zeland) I used the 2 IBM p630’s running AIX 6.1 TL05 as the OS and installed TSM 6.2 on both systems in an active/standby configuration.
The specs of the systems are as follows:
|System 1 – replication source|
|CPU core/speed||2/1453 MHz|
|volume groups||rootvg, tsmvg|
|IP address TSM interface||192.168.30.191|
|IP address replication interface||172.16.55.128|
|System 2 – replication target|
|CPU core/speed||1/1200 MHz|
|volume groups||rootvg, tsmvg|
|IP address TSM interface||192.168.30.192|
|IP address replication interface||172.16.55.129|
The following File-system structure has been setup on both systems to support the TSM application
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 786432 301552 62% 13614 26% /
/dev/hd2 4718592 419256 92% 43559 41% /usr
/dev/hd9var 1048576 526152 50% 4782 8% /var
/dev/hd3 1572864 1556832 2% 119 1% /tmp
/dev/hd1 4456448 4403144 2% 8 1% /home
/dev/hd11admin 262144 261384 1% 5 1% /admin
/proc - - - - - /proc
/dev/hd10opt 262144 58320 78% 2281 24% /opt
/dev/livedump 524288 523552 1% 4 1% /var/adm/ras/livedump
/dev/lg0dtc0 10485760 9393464 11% 43 1% /tsm/akl01_db
/dev/lg0dtc1 40370176 6650584 84% 37 1% /tsm/akl01_actilog
/dev/lg0dtc2 26214400 24724768 6% 34 1% /tsm/akl01_archlog
/dev/lg0dtc4 5242880 1554776 71% 11512 7% /opt/tivoli/tsm
/dev/lg0dtc3 1310720 461288 65% 294 1% /home/tsminst1
/dev/lg0dtc5 13107200 13046688 1% 5 1% /tsm/stg_sequ01
/dev/tsmseq02_lv 13107200 9238160 30% 6 1% /tsm/stg_sequ02
As you can see on the left hand side, all replicated filesystems are located on dtc devices /dev/lgXdtcY where lgX stands for the softek replication group and dtcY for the actual replication device.
The next code sample shows how a dtc device is being configured:
REMARK: TSM db
MIRROR-DEVNO: 1 46
The replication is setup with a symetric configuration, which means that the MIRROR-DISK also is a dtc device on the secondary system. This kind of configuration enables us in a fallback scenario to turn the replication around and replicate back to the original devices on the primary system. This fact reduces the downtime in a fallback scenario, because the application on the secondary system will only be stopped after the replication is in sync. In a non – symmetric configuration the application cannot run until the changes are replicated back from the secondary system to the primary system.
During our presentation event (Certus Enterprise Infrastructure Usergroup in Auckland in August 2010) we where able to successfully demonstrate a failover of the TSM system and started the fall back synchronization.
This setup can be applied to any database application running on AIX, Solaris, HPUX, Linux, zOS or Windows.
If I have the time I will also create a screencast of a failover and publish it here.
If anyone has questions to this setup, feel free to contact us anytime.