While InnoDB is a rather resilient storage driver, it is still possible it can get corrupted due to a disk failure or power outage. When it does happen, it’s quite possible your database will crash during startup with the following lines in the log: 170821 9:14:58 InnoDB: Assertion failure in thread 140081658566400 in file trx0purge.c […]
Mobile apps sometimes don’t work as expected, and you need to debug what the root cause is. Can you fit the whole required set of tools on one computer? Can a single PC capture network traffic and syslog from an Android or iOS device at the same time? The answer is yes. My lab setup […]
GitLab is a very useful open source code repository for developers. If you’ve ever used github.com, you know what GitLab is. It’s essentially your own, off-line GitHub. Technically speaking it’s a git server with a nice GUI, which will work just as well for standalone developers as for small companies. First off, install a minimal […]
Moving to a new PC? Setting up a new workstation? Don’t forget your PuTTy host list. Every sysadmin who has been working for a while collects a considerable number of hosts in their PuTTy configuration. Ever wondered where PuTTY saves this list? Well, it’s not in a config file you could simply copy or move. […]
So you need to change your password through RDP connection, but don’t know how to press Ctrl+Alt+Del on the remote system? Well, there’s a simple solution: press Ctrl+Alt+End instead. Yes, I was equally surprised.
ZFS is a very versatile filesystem, which can hold up to 256 zettabytes of data. Yes, that’s 2^78 bytes. It is often used in enterprise solutions, because it’s just as flexible as linux LVM, but offers additional data integrity protection, and it does it so well, that it’s often recommended to use ZFS software capabilities, rather […]
TIMESTAMP / DATETIME to Unix Time Unix timestamp handling is a bit different in MySQL and PostgreSQL, so when you’re rewriting SQL queries to work with the other database it’s good to know how to convert Unix timestamps. PostgreSQL postgres=# SELECT EXTRACT(epoch from timestamp with time zone ‘2016-02-25 12:15:17+01’); date_part ———— 1456398917 (1 row) MySQL […]
When setting up new services on a clean Red Hat or CentOS install, many administrators face problems related to the default security settings. Red Hat is secured by default, including, but not limited to, iptables firewall and SElinux, which are both enabled after installation. I will never recomend disabling iptables without trying to add required […]
Last weekend I’ve upgraded an old laptop, originally running Windows Vista, to Windows 7, in order to prepare it for the free upgrade to Windows 10, while it’s still available free of charge. After installation, Windows 7 spent a good deal of time updating itself until reaching SP1. After SP1 installation, Windows Update seemingly stopped […]
Master-slave replication can be used to replicate database to another server – as a hot standby backup, but it won’t offer any performance increase (all writes will still happen on one server). Configuring Master Database First, we set up MySQL config file vi /etc/my.cnf Find the following line to make MySQL listen on its network […]
