Enable Centrify Agent to read UID and GID from Centrify DirectManage Access Manager

We purchased Centrify Standard and setup the DirectManage Access Manager. Next we proceed to install the client agent on the compute node.

After unpacking and installing the agent, when we do a

# getent passwd  |grep kittycool
kittycool:x:1304567321211:1304567321211:kittycool:/home/kittycool:/bin/bash
kittycool:x:10001:10001:kittycool:/home/kittycool:/bin/bash

Apparently, the getent passwd |grep kittycool is pulling both the Active Directory UID and the DirectManage Access and the user UID differs

To resolve this issue, you need to specify the zone which is used by DirectManage Access Manager, so your UID of the user will pick from the DirectManage Access Manager.

# adjoin -z cluster -u OU_Administrator  staff.mycompany.com.sg -c "staff.mycompany.com.sg/HPC/Computers"

To check it is displaying the correct UID and GID,

# getent passwd  |grep kittycool
kittycool:x:10001:10001:kittycool:/home/kittycool:/bin/bash

LSF retained the original Max Locked Memory and not the updated one

The value of “max locked memory” has been modified at the operating system level, but LSF still returns the original value.

Symptoms before updating max locked memory

[user1@cluster-h00 ~]$ bsub -m compute-node1 -I ulimit -a
Job <32400> is submitted to default queue .
<>
<>
core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 1027790
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 4096
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) unlimited
cpu time               (seconds, -t) unlimited
max user processes              (-u) 1027790
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

To resolve this issue,

# badmin hshutdown
# badmin hstartup

[user1@cluster-h00 ~]$ bsub -q gpgpu -m compute-node1 -I ulimit -a
Job <32490> is submitted to queue .
<>
<>
core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 515133
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 4096
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) unlimited
cpu time               (seconds, -t) unlimited
max user processes              (-u) 515133
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

References:

1. LSF does not recognize that “max locked memory” has been updated

Algorithm negotiation failed for SSH Secure Shell Client

If you are using the dated SSH Secure Shell Client 3.2.9, you may have issue connect to the more updated OpenSSH Server.

If you cannot change the client (which is recommended), you will have to update the OpenSSH Server on Linux. Add this in

# vim /etc/ssh/sshd_config

# Ciphers
Ciphers aes128-cbc,aes192-cbc,aes256-cbc,blowfish-cbc,arcfour
KexAlgorithms diffie-hellman-group1-sha1

*If you are using Centrify-OpenSSH, you have to modify /etc/centrifydc/ssh/sshd_config and do the same

References:

1. Bug 1228013 - Server responded "Algorithm negotiation failed"  

Booting using UEFI for Lenovo Server Hardware

To boot CentOS 7.2 using UEFI. Do the following

Step 1: Choose Boot manager
Step 2 : Scroll down and look for Boot Mode
Step 3: In Boot Mode, choose System Boot mode as Uefi and Legacy Only,
Step 4: Go back to  Boot manager,
Step 5: Choose Boot from file
Step 6: Choose No volume label
Step 7: Choose EFI
Step 8: Choose Boot,
Step 9: Choose bootx64,

Virtual Box - Kernel Driver not install rc 1908 on CentOS 7

During installation of Windows 7 VM on VirtualBox-5.1, I was encountering this error during startup of the VM. Most threads will recommend you to enter into your Notebook BIOS and disable the SecureBoot and it will solve your issue. But a better solution can be found in VBox & VMware in SecureBoot Linux