When you do an SSH or SCP to a server, you may find the below error message.
“SSH returns: no macthing key type found. Their offer ssh-rsa,ssh-dss”.
You can add the -oHostKeyAlgorithms option to access the server. For example.
ssh -oHostKeyAlgorithms=+ssh-dss admin@yogindar.com
Source: SSH returns: no matching host key type found. Their offer: ssh-dss – Ask Ubuntu
Reference for Linux ERROR CODE TABLE.
Source: 131 Linux Error Codes for C Programming Language using errno
Nice tutorial on Linux kernel.
vm.min_free_kbytes setting allows kernel to compute a minimum value in the low memmory zone and reserve it for its own use.
To read the current value
[Fri Mar 24 15:18:05 root@system:~]$sysctl vm.min_free_kbytes
vm.min_free_kbytes = 1888
To set new value of 4MB. Based on your system requirement configure the value. Ideally 1.8% is good enough.
echo 4096 > /proc/sys/vm/min_free_kbytes
To configure permenantly on every reboot add the below entry to /etc/sysctl.conf
vm.min_free_kbytes=4096
Some basics on Linux Software RAID. There are good references on the same in the same wiki.
This article provides the steps to boot to single user mode and reset the root password.
A short description of how to enable root login over SSH in Linux.
Source: 5.2.2. Enable root login over SSH Red Hat Enterprise Linux 6 | Red Hat Customer Portal