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Mostrando postagens de agosto, 2020

Test NIM ports on AIX to see if are opened trhought firewall

I faced a situation where I needed test if I was able to reach a NIM server ports for the NIM service, problem is that is not so easy test all the ports, the hard way for example if you need test if would be possible resotre a machine is start the mksysb restore on the NIM and on the client, boot the server on the SMS services and see if will start normally hte installation. As per the documentation below: https://www.ibm.com/support/pages/nim-communication-within-firewall-environment You can see that thare are several port/services used by the NIM, is not feasible discover only in a critical moment that you have ports blocked on the firewall. Is not possible start all the services to test from the NIM clients. So the easy way is. You identify a service that respond for telnet on the localhost. Telnet to this service, on my case I saw the port 513 up: bash-5.0# telnet localhost 513 Trying... Connected to loopback. Escape character is '^]'. Testing from the NIM clients I was abl...

Redhat 8.2 - pam tunning using authselect

Some notes about tunning pam on RedHat 8.2 # Some tunning options got wrong, so I used the command below to restore the default configruation to be able to start again: [root@server1 pam.d]# authselect select sssd --force Profile "sssd" was selected. The following nsswitch maps are overwritten by the profile: - passwd - group - netgroup - automount - services Make sure that SSSD service is configured and enabled. See SSSD documentation for more information. # Now I create a backup from the current configuration: [root@server1 pam.d]# authselect apply-changes -b --backup=sssd.backup Backup stored at /var/lib/authselect/backups/sssd.backup Changes were successfully applied. [root@server1 pam.d]# # Here the current profile that I force to install with authselect on redhat 8.2 [root@server2 etc]# authselect current Profile ID: sssd Enabled features: None [root@server2 etc]# [root@server1 pam.d]# authselect current Profile ID: sssd Enabled features: None [root@server1 pam.d]# # Cr...

Kernel Panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Got the error, after update on Ubuntu 18.04: Kernel Panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) To solve reboot the server and on the grub menu choose advanced options to choos the old kernel. Get the Linux kernel exaclty version from grub running: grep -A100 submenu  /boot/grub/grub.cfg |grep menuentry Got the entry: menuentry 'Ubuntu, with Linux 4.15.0-112-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-4.15.0-112-generic-advanced-cb314007-7e1b-4b68-bd18-ee3fc9fccf14' { So the version that failed to boot was 4.15.0-112. So I recreated the initramfs with the command reflecting the default kernel that is booting: update-initramfs -u -k 4.15.0-112-generic And update the grup configuration: update-grub After the boot system tarted fine. Got solution from here.