Redundant Configurations, Data Integrity Options, Compression, Snapshots, Performance Enhancements September 13, 2012,
Volume 175, Issue 2
Referring to the version of Btrfs available in Oracle Linux 6 with the Unbreakable Enterprise Kernel Release 2 (Version 2.6.39) Margaret Bierman and Lenz Grimmer discuss a number of advanced capabilities available in Btrfs such as those that can be used easily and have immediate benefit to users, such as redundant configurations, data integrity options, compression, snapshots, and performance enhancements. The authors explain that with Btrfs users no longer need to use mdadm to create mirrored volumes or complex RAID configurations, as these capabilities are built into the file system. A Btrfs file system, they write, can be created on one or more devices. Additional disk drives can be added at any time to expand capacity, which do not need to be the same size or have similar geometry. Performance can be impacted if the drives have radically different performance characteristics, however. By default, Btrfs mirrors metadata across two devices and stripes data across all devices underlying the file system. Different RAID modes are supported for data and metadata, even on the same disks, they add. The balance of the paper considers the remaining aspects of Btrfsin considerable detail.