Juliet Kemp

It’s quite common to find yourself replacing machines that are still functional but just below the specs you now need — in which case it’s preferable to rehome them, rather than just throw them out. But this can have repercussions in terms of data security. Just deleting old data isn’t enough: It’s possible, if you […]

UUID (Universal Unique Identifier) notation is another way provided by Linux to access your disks. Unlike the standard /dev/hda1, /dev/sda2 notation, it is linked specifically to a particular piece of hardware (whereas /dev/ notation can shift between disks depending on how they’re plugged in). This means you don’t have the risk of a system reconfiguration […]

The SysReq key is hidden up the top right of your keyboard, and looks a bit like a relic from a former era of computing. (Which, indeed, it is.) But there’s a bunch of things you can still do with it that may come in handy. Note that this is documented only on i386 on […]

The superblock is the part of an ext2 or ext3 filesystem that contains the metadata — information about filesystem type, size, status and so on. Without the superblock, you’re in trouble in terms of data loss. Linux therefore has multiple copies of the superblock in different locations. Thus, even if you get a “bad superblock” […]

The previous column looked at using /proc to examine. There’s a lot of other information available there as well. proc is fundamentally a myth: It’s a virtual filesystem, and when you ask to read a file, it talks to other bits of the kernel, retrieves the information, and hands it back as though it were […]

The /proc directory — which provides a text-based way of interfacing with system settings and processes — looks complicated at first glance, but it can be incredibly helpful when troubleshooting. Try out these tips for looking at processes: ls /proc will show you a long list of directories. These are your processes, one directory per […]

As we are all (I hope …) painfully aware, decent backups are absolutely vital. Last week I looked at a potential option for offsite backup, and solutions like Bacula are excellent for providing a stable, reliable onsite backup, with historical data available. But these solutions don’t provide rapid access to the backed-up data in the […]

Memopal recently released a version of its software for Linux, offering an online backup service for either personal or business users. The business service allows multiuser access, so it can act as a filesharing as well as a backup service. You can get a free trial access for 7 days, but after that it’s (unsurprisingly!) […]

I’ve been using bash for years, and I still haven’t come anywhere close to mastering the full range of available command line keyboard shortcuts. I’ve found the best way to get more under my fingers is to note a few on a Post-It stuck to the monitor, and then swap it for another one at […]

LDAP allows you to have a master+slave server setup, with automatic failover in case of problems or just to spread the load. This has obvious advantages, but it can hide problems with the master server. If your master server is down but the slaves are OK, ldapsearch and other lookups will work fine. But if […]