The sys admin's daily grind: iWatch
In a Minute
Recently, sys admin Charly was faced with the task of synchronizing a directory on a server with two NFS-mounted clients. He wanted the whole thing to happen quickly and to be easily manageable, which ruled out DRBD and GlusterFS.
My sync setup looks roughly like this: An application server cyclically reads values from a database, generates HTML files and some images, and dumps everything in the /source directory. I use NFS 4 to mount the /dest1 and /dest2 directories. When any new data arrives in /source, I want it to reach the two target directories /dest1 and /dest2.
Simple and Been Here for Years
Because complex solutions are out of the question, actually the only option left is to dump the task on inotify subsystem's plate. Inotify has been part of the kernel since 2.6.13 and provides an interface to filesystem events for userspace programs.
Apart from incron [1], I've hardly found a use for it so far, but it should be ideal for quick syncing of directories – or at least, these were my ideas on the matter. What was missing was the right tool for the task. Some quick research brought to light two candidates: lsyncd [2] and iWatch [3], but I'll focus on iWatch here.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
KDE Linux Drops AUR
KDE Linux developers have dropped the Arch User Repository from the build pipeline due to security concerns; other distributions should consider doing the same.
-
California May Exempt Linux from Its Age-Verification Law
After backlash from the Linux community, California may be backing off on its promise to force all operating systems to verify age, but one platform may still have to comply.
-
Another Logic Bug Found in Linux Kernel
Qualys has discovered a vulnerability in the Linux kernel that can be used to elevate standard user privileges.
-
Ubuntu Core 26 Offers Game-Changing Enterprise Features
Ubuntu Core 26 could be a game-changer for organizations looking for increased security and reliability.
-
AI Flooding the Linux Kernel Security Mailing List
AI is giving Linus Torvalds a headache, but not in the way you might think.
-
Top Priorities for Open Source Pros Seeking a New Job
Professional fulfillment tops the list, according to LPI report.
-
Container-Based Fedora Hummingbird Designed for Agent-First Builders
Fedora Hummingbird brings the same approach to the host OS as it does to containers to level up security.
-
Linux kernel Developers Considering a Kill Switch
With the rise of Linux vulnerabilities, the kernel developers are now considering adding a component that could help temporarily mitigate against them… in the form of a kill switch.
-
Fedora 44 Now Gaming Ready
The latest version of Fedora has been released with gaming support.
-
Manjaro 26.1 Preview Unveils New Features
The latest Manjaro 26.1 preview has been released with new desktop versions, a new kernel, and more.