DB2 pureScale instance creation hangs after GPFS

While creating DB2 pureScale instance, it appears that the node becomes unresponsive under RHEL 7.2. If you reboot the node and look at the /var/log/messages, you may notice these several messages: kernel:BUG: soft lockup - CPU#1 stuck for 23s! [mmfsd:3280] The mmfsd...

DB2 pureScale Health Check

More and more customers are now asking for some way to check the health of the DB2 pureScale system. Let’s just focus on few early diagnostics before we jump to the deep exploration at the SQL statement level. This is just akin going to primary health care...

How to detect log full condition

I have seen working with hundreds of customers a chronic LOG FULL condition and the shortcut people use is to increase the LOGPRIMARY and LOGSECOND. This solution works well for a single unit of work that can not fit into the total log space available. So, first...

Kernel upgrade and impact on pureScale

In Linux environment, it is a common practice to upgrade the kernel for security patches, vulnerability fixes etc. And if you are running a DB2 pureScale environment, it is likely that you are going to break the GPFS GPL as soon as you upgrade the kernel and this will...

GPFS Disk Cleanup

During pureScale instance creation, you might run into instance creation failed condition. Under some circumstances, it is possible that db2icrt does not perform a proper clean-up for GPFS and it may fail next time complaining that the disk is already a GPFS disk....

SQL fishing using WLM

The SQLs while DB2 is up and running can be captured in different ways such as: Query column STMT_TEXT from table functions such as MON_GET_ACTIVITY or WLM_GET_WORKLOAD_OCCURRENCE_ACTIVITIES, and MON_GET_ACTIVITY_DETAILS –> SQLs that have been submitted but...

Automatic Client Reroute – Templates

Here are two templates that one can use to make Automatic Client Reroute to work properly in a HADR environment. Please note that these instructions are only valid for HADR pair in which the second machine is ready to takeover. I will publish / update this article...

Rebuild TSA Resources in HADR Environment

This is about how to rebuild TSA resources in HADR environment if you have used db2haicu in past but added resources such as tie-breaker disks that are not supported by the db2haicu tool. So, in case of a difficulty – how do you get back soon. You can always...

DB2 11.1 Rebuild TSA Resources

When you get errors like this: "SQL1517N db2start failed because the cluster manager resource states are inconsistent." or something like "Cluster manager resource states for the DB2 instance are inconsistent. Refer to the db2diag.log for more information on...

DB2 pureScale Install Problem Determination

RSCT License Issue $ db2start 128 SQL1677N  DB2START or DB2STOP processing failed due to a DB2 cluster services error DATA #9 : SQLHA Remote Command Output, PD_TYPE_SQLHA_COMMAND_RESPONSE, 3508 bytes commandResponse->callRC: 0x00000000 commandResponse->output:...

DB2 purescale Install GPL Error

GPL Compile Problem When you try to install DB2 pureScale on Linux platform (RHEL or SLES), you may receive the error. ERROR: A missing Linux package is preventing the compilation of the IBM General Parallel File System (GPFS) Portability Layer (GPL) module. The...

db2start add member fails

If you try to add a member to a running cluster, you may get the following db2start error. ERROR: The "db2start add MEMBER 2 hostname node04.purescale.ibm.local netname node04.purescale.ibm.local port 0 -iupdt" command failed with the return code: "55", and following...

Install Dropline Neu! Icons in CentOS 7.2

One of my most favorite icons on GNOME has been Dropline Neu! for many years and I still have a copy of it since 2006. It is now hard to find. Download ICON-DroplineNeu.tar.bz2 And, copy to /tmp directory # cd /usr/share/icons # tar xvfj /tmp/ICON-DroplineNeu.tar.bz2...

Drop a member in DB2 pureScale by Force

If you need to drop a member in DB2 pureScale, the db2iupdt process requires that member to be available during the drop process. But, the actual world is more cruel than what db2iupdt thinks. For example: If you have a 3 member cluster and someone moved / migrated...

Enable Fast I/O Fencing Scipt for Linux

If you install DB2 pureScale in Linux, the Fast I/O Fencing does not get enabled automatically. If you refer to Knowledge Center for DB2, you will find number of steps to enable fast I/O fencing. After DB2 instance is created and databases are created, I usually run...

Find out Slot number of PCI Card

Use dmidecode -t slot to find out the slot numbers that are in USE and the Bus Address. Use that bus address in lspci -s <busaddress> to find out what is in the slot. For example: I have NIC in slot-7, Q-Logic in Slot – 2 and Mellanox in Slot – 3. I...

WWNN and WWPN of FC Card

A FC card has a World Wide Name (WWN). Card may have two ports and each port is known as by its World Wide Port Name (WWPN). I seemed to have confused myself with WWN, WWNN and WWPN and didn’t understand the difference as this is not my topic. In the example...

DB2 pureScale rebuild TSA Resources

In order to be a successful DB2 pureScale DBA, one has to learn how to diagnose and fix TSA. Though, this is not necessary but it will help to fix cluster in case you run into situation when you get messages like "SQL1517N db2start failed because the cluster manager...

TCPIP Tuning at VIOS and AIX

This is for for my own reference and does not constitute any recommendations. VIO Server Changes Verify flow_control is set to yes – This is the default setting lsattr –El ent0 | grep flow and lsattr –El ent1 | grep flow chdev -l ent0 –a flow_control=yes chdev...

Avoid Tie Breaker Disk

It is possible to avoid tie breaker disk in pureScale and HADR just by following a simple majority rule. You need a tie breaker disk in pureScale and HADR if number of hosts are even. So, in HADR you have only two nodes so your need a tie breaker disk. But, even in...