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I’ve just had to do yet another backup/format/restore operation on my workstation due to a BTRFS corruption problem, but as usual I didn’t lose any data. The BTRFS data integrity features work reasonably well even when the filesystem gets into a state where the kernel will only accept a read-only mount.

Given that the BTRFS [...]


For some years LVM (the Linux Logical Volume Manager) has been used in most Linux systems. LVM allows one or more storage devices (either disks, partitions, or RAID sets) to be assigned to a Volume Group (VG) some of which can then allocated to a Logical Volume (LVs) which are equivalent to any other block [...]

Swap Breaking SSD

I’ve seen many comments about swap space and SSD claiming that swap will inherently destroy SSD through using too many writes. The latest was in the comments of my post about swap space and SSD performance [1]. Note that I’m not criticising the person who commented on my blog, everyone has heard lots of reports [...]

BTRFS Status April 2014

Since my blog post about BTRFS in March [1] not much has changed for me. Until yesterday I was using 3.13 kernels on all my systems and dealing with the occasional kmail index file corruption problem.

Yesterday my main workstation ran out of disk space and went read-only. I started a BTRFS balance which didn’t [...]

Swap Space and SSD

In 2007 I wrote a blog post about swap space [1]. The main point of that article was to debunk the claim that Linux needs a swap space twice as large as main memory (in summary such advice is based on BSD Unix systems and has never applied to Linux and that most storage devices [...]

Finding Corrupt Files that cause a Kernel Error

There is a BTRFS bug in kernel 3.13 which is triggered by Kmail and causes Kmail index files to become seriously corrupt. Another bug in BTRFS causes a kernel GPF when an application tries to read such a file, that results in a SEGV being sent to the application. After that the kernel ceases to [...]

BTRFS Status March 2014

I’m currently using BTRFS on most systems that I can access easily. It’s not nearly reliable enough that I want to install it on a server in another country or an embedded device that’s only accessible via 3G, but for systems where I can access the console it’s not doing too badly.

Balancing and Space [...]

Cheap Bulk Storage

The Problem

Some of my clients need systems that store reasonable amounts of data. This is enough data that we can expect some data corruption on disk such that traditional RAID doesn’t work, that old fashioned filesystems like Ext3/4 will have unreasonable fsck fimes, and that the number of disks in a small server isn’t [...]

BTRFS and ZFS as Layering Violations

LWN has an interesting article comparing recent developments in the Linux world to the “Unix Wars” that essentially killed every proprietary Unix system [1]. The article is really interesting and I recommend reading it, it’s probably only available to subscribers at the moment but should be generally available in a week or so (I used [...]

ZFS vs BTRFS on Cheap Dell Servers

I previously wrote about my first experiences with BTRFS [1]. Since then I’ve been using BTRFS on more systems and have had good results. The main problem I want to address is with the reliability of RAID [2].

Requirements for a File Server

Now one of my clients has a need for a new fileserver. [...]