Recently I bought a Soekris net6501 to build a home network in my new house. Things you need before you start: – USB / mSSD drive to install OpenBSD on – USB drive to boot from – Serial cable for … Continue reading
Tag Archives: SysAdmin
OSSEC is an Open Source Host-based Intrusion Detection System that performs log analysis, file integrity checking, policy monitoring, rootkit detection, real-time alerting and active response. It runs on most operating systems, including Linux, MacOS, Solaris, HP-UX, AIX and OpenBSD. There … Continue reading
IMAP folders are really because you can have your e-mails synchronized on multiple devices, without losing e-mails across your devices when retrieving your new e-mails. IMAP folders actually also aren’t that cool because e-mails are usually never deleted or even … Continue reading
At my recent job, I was asked to create a backup procedure, which would dump a PostgreSQL schema to a compressed file and which was able to create weekly and daily backups. The backups had to be full backups each … Continue reading
Update: This article is updated thanks to Colin Keith his excellent comment. I was extremely inspired by it Maintaining a large number of servers cannot be done without proper programming skills. Each good system administrator must therefor make sure he … Continue reading
Not using indexes or huge tables without indexes, can have a very negative impact on the duration of a SQL query. The query planner will decide to make a sequence scan, which means that the query will go through the … Continue reading
Working on large database systems, with many tables and many indexes, it is easy to loose the overview on what is actually being used and what is just consuming unwanted disk space. If indexes are not closely monitored, they could … Continue reading
Since the release of OpenSSH 6.2, two new configuration parameters have been added: AuthorizedKeysCommand AuthorizedKeysCommandUser These parameters allow to create any kind of authentication method for OpenSSH, including LDAP authentication, and therefore patches like the LPK patch for OpenSSH are … Continue reading
If you have a hosting account at Hetzner with free backup space, you can not access this backup volume using rsync. One way of creating a simple backup, is by using the tar command with the incremental option. You will … Continue reading
Below is a small Perl example how to check for NFS mounted shares on a Linux host. The script does not need any specific modules, and makes use of the /etc/mtab file.
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#!/usr/bin/perl use strict; use warnings; my @mount_points = do {local @ARGV = '/etc/mtab'; <>}; foreach my $mnt (@mount_points){ next unless $mnt =~ /nfs/; my ($node, $mnt_point, $fs, $options, $dump, $fsck) = split /\s+/, $mnt; print "Found NFS share $node mounted on $mnt_point\n"; } |