These days we are doing some maintenance tasks on hundreds of RHEL servers and we update them using a shell script. We failed to update part of them and after I fixed the failure I would like to share...
How to display the obsoleted packages and versions of a RPM?
These days I patched some servers using a standard script and it run successfully on most nodes until last night.It failed on two nodes and the primary issue was about the python34 package.I g...
Talking about ‘recovery window of 7 days’
Sometimes we will keep the database backup for one week and set the retention policy to 'recovery window of 7 days'. So we will only keep the database backup for 7 days, right?In fact, it depends....
LifeThinkPad E485 memory compatibility issue
For a long time I used my old T420s laptop as primary device while it could only support 16G memory. So at the beginning of June, I bought a new laptop ThinkPad E485 which had 8 CPU cores and could su...
Xntpd restarted due to no time server selected
Handled a ntp issue these days and I want to share my learning here as I could not find the right and detail explanation until now.The error message was like the title and when I checked the ntp s...
PVG concept in AIX LVM
Long time ago, when I studied the Veritas LVM, I knew the PVG term which meant physical volume group and the physical volumes in the same PVG were from the same SAN or same disk. Usually there is a si...
Configure iSCSI target on latest NexentaStor Community Edition
Last night I installed the latest NexentaStor Community Edition (5.2.1) and tried to create an iSCSI target then added it to some ESXi nodes to build my home lab environment.At the beginning I tho...
ORA-27102 out of memory on a system with huge memory
Today one customer said the data sync of Oracle Dataguard had issue and our guys checked the alert log then sent below errors to me:
ORA-01034: ORACLE not available
ORA-27102: out of memory
Linux-x...
The difference between IP address and Hostname when creating SSH User Equivalency
I provided a 12c RAC step-by-step installation guide to client and he got issue during the deployment. Be specific, he failed the SSH User Equivalency:
$ ssh -o FallBackToRsh=no -o PasswordAuthentica...
Maybe a dangerous configuration of ASM diskgroup with Normal Redundancy
These days my friend Zhiguo discussed with me about the vote disk issue of Normal Redundancy ASM disk group and I found maybe I made a big mistake.Nowadays more and more customers install two SSD ...
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