Linux

Uname command with examples

Uname command in Linux

1. uname command

The uname command prints information about the system. uname is a portmanteau word made up from "unix" and "name". uname can be called from the command line in Linux as,

uname [OPTION]...

The most common way to use uname is with the -a option, which stands for "all" the information.… Read more

MCE hardware error cpu 0

1.0 Error

Error

While running Ubuntu 18.04.1 on a laptop, the following errors were observed.

mce: hardware error cpu 0 machine check 0 bank 6 ae0000000040110a
mce: hardware error tsc 0 addr ffb07540 misc 238a0000086
mce: hardware error processor 0:40651 time 1540082330 socket 0 Apic 0 microcode 24
ipmi dmi invalid offset 0

The system would stop in the single user mode.… Read more

Signals in Linux

Timeout

1.0 Signals

Signals are software interrupts that are delivered to a process by the kernel. A signal indicates that an event has occurred and the process must take note of it. A signal is delivered asynchronously to a process. Whatever the process was doing is suspended and the processing of the signal takes place immediately.… Read more

Syslog

1.0 Syslog

Syslog is a protocol for conveying event notification messages.

Syslog was first developed by Eric Allman for logging as a part of the Sendmail project in the 1980s. It soon became a de-facto standard for logging on Unix-like systems.… Read more

Dovecot: imap Error: open (/var/mail/username) failed

Error

While configuring mail on a Ubuntu Linux server running the Postfix mail server and Dovecot IMAP server, the following errors were observed in the mail log files,

dovecot: imap(user1): Error: open(/var/mail/user1) failed: Permission denied (euid=1002(user1) egid=1002(user1) missing +w perm: /var/mail, we're not in group 8(mail), dir owned by 0:8 mode=0775)
dovecot: imap(user1): Error: Failed to autocreate mailbox INBOX: Internal error occurred.
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