Linux

Last week, got this issue reported by a DBA that he wasn’t able to su to oracle user from root on a Oracle Base Database VM in OCI. The login of opc user worked fine and he could do sudo su to root but he couldn’t su to oracle. When he did it just came back to root shell. [root@xxx ~]# su - oracle Last login: Fri Jan 12 10:20:38 UTC 2023 [root@xxx ~]# There was nothing relevant in /var/log/messages or /var/log/secure. I tried it for some other user and it worked fine. Then I suspected something with the profile of oracle user and voila ! The .bashrc looked like this ...

To put it in bit of an Indian context, database is not your daughter-in-law that you can blame it for every performance issue that occurs in the environment. But it does happen. Most of the time it is the database that is blamed for all such issues. Many times, the issues are in some other layer like OS, network or storage. Faced this issue recently at one of the customer sites where performance in one of the databases went down suddenly. It was a 2 node RAC on 12.1.0.2 running on Linux 7 using some kind of Hitachi SSD storage array. There were no changes as per DBA, application, OS and storage teams. But something must have changed somewhere. Otherwise why would performance degrade just like that. I & my colleague checked some details and found that something happened in the morning a day before. Starting from that point in time, the execution time for all the commonly run queries shot up. Generally speaking, when all the queries are doing bad and you are sure that nothing has been changed on the database side, the reasons could be outside the database. But being a DBA, it is not easy to prove that. We took AWRs from good and bad times and the wait events section looked like this: ...

A colleague faced this while running FMW installer on a Linux machine. The display appeared like this This thread gave a clue that it could have something to do with fonts. So I checked what all fonts related stuff was installed. [bash][root@someserver ~]# rpm -aq |grep -i font stix-fonts-1.1.0-5.el7.noarch xorg-x11-font-utils-7.5-20.el7.x86_64 xorg-x11-fonts-cyrillic-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-1-75dpi-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-9-100dpi-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-9-75dpi-7.5-9.el7.noarch libXfont-1.5.2-1.el7.x86_64 xorg-x11-fonts-ISO8859-14-100dpi-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-1-100dpi-7.5-9.el7.noarch xorg-x11-fonts-75dpi-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-2-100dpi-7.5-9.el7.noarch libfontenc-1.1.3-3.el7.x86_64 xorg-x11-fonts-ethiopic-7.5-9.el7.noarch xorg-x11-fonts-100dpi-7.5-9.el7.noarch xorg-x11-fonts-misc-7.5-9.el7.noarch fontpackages-filesystem-1.44-8.el7.noarch fontconfig-2.10.95-11.el7.x86_64 xorg-x11-fonts-ISO8859-2-75dpi-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-14-75dpi-7.5-9.el7.noarch xorg-x11-fonts-Type1-7.5-9.el7.noarch xorg-x11-fonts-ISO8859-15-75dpi-7.5-9.el7.noarch [root@someserver ~]#[/bash] ...

One of my friend today asked me about removing Linux partitions & GRUB (from a dual boot system) and return back to windows alone. Removing Linux involves just formatting/removing the partitions. Now to remove GRUB either do fdisk /mbr from a Windows 98 bootable CD or do fixmbr after booting into repair mode with Windows XP CD. But if you have none then to remove GRUB you will need some utility like this one and if you reboot before doing that it might make GRUB unable to boot into Windows. It will get stuck at GRUB> prompt only. So there is an option: to manually boot the OS you want (ie Windows). A quick search gave link to this thread. It involves few commands on the GRUB prompt: ...