SMART is a monitoring system, included in most modern hard disks, that attempts to diagnose disk health and predict impending drive failure. The smartctl/smartd utility of smartmontools is the standard for Linux/Unix and versions of it are available for Windows as well. DiskCheckup also seems to be a good utility for Windows. Many modern controller […]
Tag: Linux
Quick Setup Notes for Debian
Some quick setup notes for Debian 8 (“Lennie”). Add yourself to the sudoers group: Set up unattended security updates: (Select ‘yes’ to the ‘Automatically download’ question.) Install all tools for dev/package builds: (Alternatively, installing build-essentials will give you all standard c/c++/make/dpkg libraries, although not the kernel headers.) “Permission denied” CD-ROM error: Optical drives and network […]
SATA Disk Inspection and Troubleshooting
The purpose of this page is to list some tools for SATA disk or device troubleshooting on Unix-like operating systems. Serial ATA is specified by the SATA International Organization; the most current revision as of October 2015 is SATA 3.2, released August 2013. Intel specifies the Advanced Host Controller Interface; as of October 2015 the […]
RAID Levels
This is a summary of standard and nested RAID levels that I might implement either in a small home/office environment or from enterprise vendors. I’m avoiding the rarely-seen levels like 2, 3, and 4 as well as vendor-specific “RAID” implementations like RAID-S or X-RAID. Fortunately, many major vendors like Dell, Supermicro, and Silicon Mechanics are […]
tcpdump
tcpdump is a useful packet analyzer distributed under the BSD license. It is included with most Linux and Unix distros, and it’s available for Windows using the Winpcap library. As you might imagine, tcpdump is excellent at troubleshooting problematic connections to remote systems where the cause is otherwise unclear. This is particularly useful for getting […]
sed and awk
sed and awk are two powerful but often overlooked data processing tools, and if you know how to use them effectively you’ll be well ahead of many sysadmins and developers. sed sed is an in-place stream editor, that is, it accepts input from a file or STDIN, manipulates the data stream in some way, and […]
grep
grep is a useful utility that finds fixed strings or patterns of text in a given file or standard input. Used in conjunction with error logs or debugger output, grep can help a programmer identify errors in an application code base or filesystem; to help with this, grep understands regular expressions, what it calls “extended” […]
LOC Records
LOC records allow WGS84 location to be published via the Domain Name Service. They are defined in RFC 1876. If a host has a LOC record, it can be looked up via dig -t loc: LOC records are expressed in terms of Degrees-Minutes-Seconds, not decimal latitude and longitude. You can convert them using a tool […]
Reset the MySQL Root Password
So you don’t know your MySQL root password but you do have the root password of the server. Here’s a quick way to reset your MySQL root password on the command line: 1. Stop MySQL 2. Start MySQL in safe mode without a password 3. Log into your database server without a password, and reset […]
TrueCrypt on Fedora Linux
Update 2015: Support and development of TrueCrypt have, of course, now ended, although an independent audit of TrueCrypt revealed no severe security problems. I’d suggest the TrueCrypt fork VeraCrypt as a replacement. Note: I’m using Fedora 19 here. Results will vary on different versions. If you’re trying to run the TrueCrypt virtual disk encryption software […]