If you see the following error in the alert log of the new primary server during a switchover, that's normal. It's a transient one. ******************************************************************** Fatal NI connect error 12514, connecting to: (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(Host=OL6DB01)(Port=1521)))(CONNECT_DATA=(SERVICE_NAME=PROD1)(CID=(PROGRAM=oracle)(HOST=ol7db02)(USER=oracle)))) VERSION INFORMATION: TNS for Linux: Version 184.108.40.206.0 - Production TCP/IP NT Protocol Adapter for Linux: Version 220.127.116.11.0 - Production Time: 30-OCT-2020 15:08:40 … Continue reading Fatal NI connect error 12514 and TNS-12564
Month: October 2020
runlevel returns “unknown” on Oracle Linux 7
systemd has replaced SysVinit as the default service manager in Oracle Linux 7 (RHEL 7), but for the backward compatibility reason, the runlevel command is still available and it is a symbolic link to systemctl. Some old programs relies on the return result of runlevel to continue such as Oracle 12c installation prerequisite checks. I … Continue reading runlevel returns “unknown” on Oracle Linux 7
OPatch needs exec option on /tmp
I was installing Oracle 12c release 1 on a Oracle Linux 6 system yesterday and it failed when patching Oracle with PSU#190716. I've done this many times and haven't seen any issues. In the log, it showed following errors: Start OOP by Prereq process. Launch OOP… /opt/oracle/121020/OPatch/opatch: line 1397: /tmp/oracle-home-160383738077277/OPatch/opatch: Permission denied /opt/oracle/121020/OPatch/opatch: line 1397: … Continue reading OPatch needs exec option on /tmp
Today I was asked by a colleague how to display a human readable timestamp for the output of dmesg. Indeed on some Linux distributions or old Linux systems, dmesg's output will have something like: [57494.681117] perf: interrupt took too long (2502 > 2500), lowering kernel.perf_event_max_sample_rate to 79000[87459.446474] perf: interrupt took too long (3152 > 3127), … Continue reading dmesg timestamp
Always looking for an easy life.
Windows system GUI is straightforward for administrators if you have some light duties occasionally and know what to do -- a few clicks and it's done. However, sometimes you get tasks which needs to be repeated many times on different objects -- either you still keep clicking until you feel tired or wonder if there … Continue reading Always looking for an easy life.
Rebuilding database from scratch due to an interruption
Last week I was using DBCA to create a 19c database using the silent mode. My SSH connection lost during the process and I had to restart the creation again, but ran into two issues again: DBCA was complaining about existing GDB name (Oracle SID). [WARNING] [DBT-10328] Specified GDB Name (JOEPROD) may have a potential … Continue reading Rebuilding database from scratch due to an interruption
SSH “timed out waiting for input: auto-logout”
For a secured Linux system, normally there will be auto logout configured for SSH. It means if your SSH session has no activities for some time configured, the session will be disconnected. It's a problem if you need to run some kind of interative long-running progams because such programs need some imputs in the middle … Continue reading SSH “timed out waiting for input: auto-logout”
Wonder where SSH sessions come from?
Today I needed to connect to a customer site to check something and the last time I connected to this site was 6 month ago. At that time I installed tmux on one of their Linux servers. So I was hoping my tmux session was still there and could reuse it. However, my VPN history … Continue reading Wonder where SSH sessions come from?