Download of the day: Linux Kernel 2.6.28

Posted on in Categories Download of the day, kernel, Linux last updated December 27, 2008

Linux kernel version 2.6.28 has been released and available for download. The new version includes following stable and new features:

a] ext4 file system – The ext4 filesystem can support volumes with sizes up to 1 exbibyte and files with sizes up to 16 TiB. ext4 removes ext3 64-bit storage limits and adds other performance improvements.

b] Graphics Execution Manager (GEM) – It is a a modern memory manager specialized for use in device drivers for graphics chipsets. It manages graphics memory, controls the execution context and manages the Non-Uniform Memory Access (NUMA) environment on modern graphics chipsets. The “xf86-video-intel” device driver will feature GEM integration.

c] Other features – Stable USB drivers, KVM, bug fixes and other stuff.

=> Download Linux kernel 2.6.28 here. You may also find our kernel compile tutorial useful.

Security Update: Debian Linux Kernel Local / Remote Vulnerabilities

Posted on in Categories Debian Linux, kernel, Linux distribution, Security Alert last updated December 4, 2008

Debian project today released a pair of security updates to plug at least ten security holes in its core called Linux kernel. Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service or privilege escalation. This update has been rated as having important security impact.

mount forcedirectio: Disable Linux CIFS / NFS Client Caching

Posted on in Categories CentOS, File system, GNU/Open source, kernel, Linux, Linux Scalability, RedHat/Fedora Linux, Storage, UNIX last updated November 16, 2008

If your network is heavily loaded you may see some problem with Common Internet File System (CIFS) and NFS under Linux. By default Linux CIFS mount command will try to cache files open by the client. You can use mount option forcedirectio when mounting the CIFS filesystem to disable caching on the CIFS client. This is tested with NETAPP and other storage devices and Novell, CentOS, UNIX and Red Hat Linux systems. This is the only way to avoid data mis-compare and problems.

How To Use vi as Default Editor and Viewer in Midnight Commander

Posted on in Categories File system, Howto, Linux, Shell scripting, Tips, UNIX last updated November 3, 2008

Midnight Commander (mc) is an user-friendly text-based file manager UI for Unix. Using mc, you can browse the filesystem easily and manipulate the files and directories quickly. You will not miss the standard command line prompt, which is also available within the mc itself. If you are new to mc, Midnight Commander (mc) Guide: Powerful Text based File Manager for Unix article will give you a quick jumpstart. In this article, let us review how to solve couple of common annoyance about viewing a file in mc.

Download of the day: Linux Kernel 2.6.25

Posted on in Categories Download of the day, Linux last updated April 17, 2008

Linux kernel 2.6.25 has been released and available for download from the official website. After nearly three months of development and the merging of over 12,000 patches from almost 1200 developers, this kernel is now considered ready for wider use. Highlights of this release include the ath5k (Atheros wireless) driver, a bunch of realtime work including realtime group scheduling, preemptable RCU, LatencyTop support, a number of new ext4 filesystem features, support for the controller area network protocol, more network namespace work and much more. LWN has more information.

Related: How To Compile Linux kernel 2.6.xx.

Download of the day: FreeBSD 7.0 ISO / CD Image

Posted on in Categories Download of the day, FreeBSD last updated February 28, 2008

FreeBSD 7.0 stable has been released and available for download. FreeBSD is back to its incredible performance. According to some benchmarks on both Intel and AMD 64 bit systems FreeBSD 7.0 being faster than Linux 2.6 when running PostreSQL or MySQL. It has experimental support for Sun’s ZFS filesystem. gjournal can be used to set up journaled filesystems, gvirstor can be used as a virtualized storage provider. Please see complete release note including upgrade instructions here. There is also interview published with FreeBSD developers

Download FreeBSD 7.0

You can download FreeBSD 7.0 ISO file from FTP server

You can also use Bittorent to grab FreeBSD 7.0 ISO files

Comparison: Linux and UNIX ~ ZFS vs XFS vs EXT4 filesystem

Posted on in Categories File system, Linux, Sys admin, Tips, UNIX last updated August 30, 2007

This is an interesting filesystem comparison. If you are looking to build cheap storage for personal use file system decision is quite important:

This is my attempt to cut through the hype and uncertainty to find a storage subsystem that works. I compared XFS and EXT4 under Linux with ZFS under OpenSolaris. Aside from the different kernels and filesystems, I tested internal and external journal devices and software and hardware RAIDs. Software RAIDs are “raid-10 near2” with 6 disks on Linux. On Solaris the zpool is created with three mirrors of two disks each. Hardware RAIDs use the Areca’s RAID-10 for both Linux and Solaris. Drive caches are disabled throughout, but the battery-backed cache on the controller is enabled when using hardware RAID.

=> ZFS, XFS, and EXT4 filesystems compared

Why my Linux server ext3 filesystem go read-only?

Posted on in Categories Ask nixCraft, CentOS, File system, Linux, RedHat/Fedora Linux, Sys admin, Tips, Troubleshooting, Ubuntu Linux last updated August 28, 2007

From my mailbag:

We have 5 Dell server collocated running CentOS 4.x and 5.x server operating system. Sometime my file system (ext3) goes read-only. I’d like to know what could be causing such a problem?

My guess:
a) Hardware problem / hard disk problem, check harddisk for errors.

b) High disk I/O aka busy I/O retry error can mark low level disk call as failed. This will force ext3 to go into read only mode.

c) High disk I/O on SAN

d) SAN is not configured properly for the path failover.

In all sort of problems ext3 goes read-only to protect the filesystem and further damage. If you are using VMWARE, check out official webpage to download SCSI patches or workaround for vmware problems.

So what could be causing the file system on Linux go read-only?

Apart from above generic problem, any other error can trigger filesystem on Linux go read only. I hope our reader / seasoned Linux admin can help to answer this question. Please share the experiences and advice in the comments.

ZFS on Linux using FUSE

Posted on in Categories File system, GNU/Open source, Linux, Solaris, UNIX last updated June 19, 2007

Linus Torvalds called ZFS one of the very few bright spots in Solaris. ZFS released under Sun’s Common Development and Distribution License. Linux is under GPL v2 which makes ZFS incompatible with Linux. I’ve used ZFS under Solaris and it is absolutely rocking file system.

Now this hot feature from OpenSolaris is taking a weird but working path to Linux inclusion using FUSE (Filesystem in Userspace).

If you like Linux for the long list of supported hardware but Solaris for the advanced new ZFS filesystem, a new development project might have a happy surprise for you. One advantage to putting ZFS into a separate daemon is the same as something that microkernel operating system developers have been talking up for years: You can kill and restart the filesystem independently of the operating system.

Check out official ZFS on FUSE blog and LinuxWorld article for more information ZFS on Linux: It’s alive