DNF (Dandified YUM) DNF is the next version of  YUM (YUM is a package manager for RPMs).  dnf roughly maintains CLI compatibility with yum and existing AIX Toolbox repositories created for yum are working good with dnf too, so no changes needed in repository side. yum is based on python2 and python2 is out of support, so there was a need to move to python3, dnf  works with python3. AIX Toolbox News: https://www.ibm.com/support/pages/node/6833478 DNF install: https://community.ibm.com/community/user/power/blogs/sangamesh-mallayya1/2021/05/28/dnf-is-now-available-on-aix-toolbox ..read more

iSCSI iSCSI (Internet SCSI) provides access to storage devices by carrying SCSI commands over a TCP/IP network.  iSCSI was developed by IBM and Cisco in 1998 and submitted as a draft standard in March 2000. NetApp is one of the leader company in storage hardware industry. In the early 1990s, NetApps's storage systems offered NFS and SMB protocols (based on TCP/IP) and in 2002 NetApp added Fibre  Channel (FC) and iSCSI protocols. iSCSI protocol is configured to use TCP port number 3260. The iSCSI protocol allows clients (called initiators) to send SCSI commands to storage devi ..read more

Welcome to AIX for System Administrator! This blog is intended for anyone who is working with AIX and encountered problems and looking for fast solutions or just want to study about AIX. This is not a usual blog, it is not updated every day. I tried to organize AIX related subjects into several topics, and when I find new info/solutions/interesting stuff I will add it to its topic. You can read here about many things of the world of AIX. (NIM, Storage, Network, VIO, PowerHA, HMC, Performance Tuning...) The structure of each subject is very similar. First I try to give a general overview ..read more

fcstat The fcstat command reports statistics directly from the FC adapter firmware and the FC driver. Protocols such as TCP/IP are designed to tolerate packet loss and out-of-order packets with minimal disruption, but the FC protocol is in-tolerant of missing, damaged or out-of-order frames and is incapable of re-transmitting a single missing frame. This moves error recovery into the SCSI layer and can result in waiting for commands to timeout. In some cases an error frame is not detected by either the target or the initiator, so it just waits for completion until 30 or 60 seconds to timeou ..read more

Oracle - Tuning Resource Limits ulimits (smit chuser or edit /etc/security/limits to create a stanza for Oracle/grid user and set -1 (unlimited) for everything except core. oracle:  data = -1  stack = -1  fsize_hard = -1  cpu_hard = -1  data_hard = -1  stack_hard = -1  fsize = -1  nofiles = -1  cpu = -1  rss = -1 Soft File Descriptors  at least 1024 KB Hard File Descriptors  at least 65536 KB maxuproc:m aximum number of PROCESSES allowed per user (smit chgsys). Set this value to 16386 (16k) ncargs: 128 ..read more

Oracle ASM, RAC, Data Guard ASM (Automatic Storage Management) ASM is Oracle's recommended storage management solution. Oracle ASM uses disk groups to store data files. A disk group consists of multiple disks and for each ASM disk group, a level of redundancy is defined (normal (mirrored), high (3 mirrors), or external (no ASM mirroring)). When a file is created within ASM, it is automatically striped across all disks allocated to the disk groups. The performance is comparable to the performance of raw devices. ASM allows disk management to be done using SQL statements (such as CREATE, ALTE ..read more

Oracle Basics Oracle Server It is an Oracle instance + an Oracle database Oracle Instance It consists of memory and process structures to provide access to the database Oracle Database It consists of data-, control- and redo log files Oracle has changed the database naming convention starting with Oracle 12.2. Oracle database 18c (year 2018) is the full release of 12.2.0.2. The recommended database product to target would be 19c as it offers a greater duration of support by Oracle to March 2026. Beginning with release 12.2.0.2, new releases will be annual. The version will be the last two d ..read more

Novalink Novalink is a sort of "replacement" of the HMC. In a usual installation all Openstack services (Neutron, Cinder, Nova etc.) were running on the PowerVC host. For example the Nova service required 1 process for each Managed System: # ps -ef | grep [n]ova-compute nova       627     1 14 Jan16 ?        06:24:30 /usr/bin/python /usr/bin/nova-compute --config-file /etc/nova/nova-9117MMD_10D5555.conf --log-file /var/log/nova/nova-compute.log --log-file /var/log/nova/nova-compute-9117MMD_10D5555.log nova       649 ..read more

Git Basics The purpose of Git is to keep track of the changes, which have been made on files. In more official wording: Git is a distributed version control system. Version Control System can be any software that records changes to files over time so that you can recall specific versions later. It helps software teams to keep track of modifications to the source code. If a mistake is made, developers can turn back the clock and compare earlier versions of the code to help fix the mistake. (Git was created by Linus Torvalds in 2005 to help during the development of the Linux Kernel with other ..read more

Red Hat - Netboot and Install from NIM server A NIM server can boot up and install AIX servers from network using TFTP, BOOTP protocols. As other operating systems are using these same protocols for network boot (and install), our NIM server could be utilized for network booting and installing RHEL 6 or 7 servers as well. The process is basically the same on each environment, but the setup and configuration is different for AIX, RHEL 6 and RHEL 7. (In the Linux world there are many other methods to achieve this, like a Kickstart server, here wanted to show that NIM server is capable of doing ..read more