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.
The default is to attempt to cache ie try to request oplock on files opened by the client (forcedirectio is off). Foredirectio also can indirectly alter the network read and write size, since i/o will now match what was requested by the application, as readahead and writebehind is not being performed by the page cache when forcedirectio is enabled for a mount
mount -t cifs //mystorage/data2 -o username=vivek,password=myPassword,rw,bg,vers=3,proto=tcp,hard,intr,rsize=32768,wsize=32768,forcedirectio,llock /data2
Refer mount.cifs man page, docs stored at Documentation/filesystems/cifs.txt and fs/cifs/README in the linux kernel source tree for additional options and information.
Fedora Linux 9 beta has been released and available for download. Some highlights of Fedora 9 Beta:
=> GNOME 2.22, with new features like a helpful world time clock, better file system performance, security improvements, power management at the login screen, the ability to dynamically configure displays, better Bluetooth integration, improved podcast support, and many other enhancements
=> KDE 4.0.2, which includes a brand new desktop and panel with many new concepts, integrated desktop search, a brand new visual style called Oxygen, a new multimedia API called Phonon, and a new hardware integration framework called Solid -- all integrated by Fedora's KDE SIG
=> Firefox 3 Beta 5, featuring a native look and feel, desktop integration, the new Places that replaces bookmarks, and a reworked address bar
=> Support for resizing ext2, ext3 and NTFS partitions during install
=> Support for creating and installing to encrypted filesystems
=>PackageKit, a cross-distribution package management solution with a complete yum backend, designed to unify different distributions' software management with the latest technologies
=> Kernel 2.6.25-rc5 etc
Download Fedora 9 Beta Software
To download, visit:
kfsmd is an interesting tool to keep track of changes in your filesystems. This tool based upon inotify which is a Linux kernel subsystem that provides file system event notification. Useful for file auditing. From the article:
Applications can ask the Linux kernel to report changes to selected files and directories. I created the Kernel Filesystem Monitoring Daemon (kfsmd) to make monitoring filesystem changes simple. Command-line clients for kfsmd come in two categories: monitoring and logging. The monitoring client produces output on the console whenever something happens to a filesystem you are watching. You can log to either a Berkeley DB4 file or a PostgreSQL database.