Tag Archives: Linux File Systems

ZFS hits an important milestone, version 0.6.1 released

ZFS on Linux is one of the many important open source projects and this project has reached what Brian Behlendorf calls an important milestone with the official 0.6.1 release. ZFS is a combined file system and logical volume manager which was originally designed by Sun Microsystems.

Version 0.6.1 not only brings the usual bug fixes but also introduces a new property called ‘snapdev’.

Brian explains, “The ‘snapdev’ property was introduced to control the visibility of zvol snapshot devices and may be set to either ‘visible’ or ‘hidden’.  When set to ‘hidden’, which is the  default, zvol snapshot devices will not be created under /dev/.  To gain access to these devices the property must be set to ‘visible’  This behavior is analogous to the existing ‘snapdir’ property.

Other important changes include:

  • Added Linux 3.9 compatibility
  • Added snapdev property to control visibility of zvol snapshots.
  • Disabled old on-disk format warning for `zpool status -x`.
  • Enabled zfs_arc_memory_throttle_disable by default.
  • Improved slab object reclaim behavior.
  • Fixed disk cache flushing for 2.6.37 and newer kernels.
  • Fixed hot spare functionality.
  • Git <id>-<hash> included in release for working builds.
  • Updated dkms and kmod compliant packaging.
  • Added man pages for splat, fsck.zfs, mount.zfs, zhack, zinject, zpios, ztest, and zpool-features.

Some of the important features of ZFS include protection against data corruption, support for high storage capacities, integration of the concepts of filesystem and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z and native NFSv4 ACLs. ZFS is implemented as open-source software, licensed under the Common Development and Distribution License (CDDL).

The team has made available the tarballs from zfsonlinux.org. They have also simplified the installation and management of ZFS for different operating systems by creating repositories for Debian, Fedora, and RHEL/CentOS.

Samsung Creates New File System F2FS For Linux, Good News For Android

Samsung has created a new Linux file system called F2FS. Jaegeuk Kim of Samsung writes on the Linux Kernel Mailing List:

“F2FS is a new file system carefully designed for the NAND flash memory-based storage devices. We chose a log structure file system approach, but we trid to adapt it to the new form of storage. Also we remedy some known issues of the very old log structured file system, such as snowball effect of wandering tree and high cleaning overhead.

Greg KH, the lead Linux kernel developer applauded the file system on his Google+ page, “Sweet, a new Linux file system from Samsung that is faster than existing ones when running on flash storage devices, submitted in a clean, easy-to-apply manner.  This will be great for Android-based systems.”

The file stystem is targeted at NAND flash memory based devices as Kim explains, “NAND flash memory-based storage devices, such as SSD, eMMC, and SD cards, have been widely being used for ranging from mobile to server systems. Since they are known to have different characteristics from the conventional rotational disks, a file system, an upper layer to the storage device, should adapt to the changes from the sketch.”

The new file system is great news for Android and also brings Samsung on the ‘forefront’ as an important contributor to the development of Linux and Android.