Subject: ntfs-3g-1.910-RC released
Newsgroups: gmane.comp.file-systems.ntfs-3g.devel
Date: 2007-09-10 00:25:45 GMT (1 year, 42 weeks, 4 days, 3 hours and 20 minutes ago)
Hi, There were some feedbacks about coping many files is slow. We took a look and improved the speed typically by 50-1000%. It's not a typo. The higher value we have measured was indeed one thousand percentage. Here it is what was going on. When applications wrote files and the file size were not a multiply of the block size (over 99.995% of all cases) then when ntfs-3g made a write request to the Linux kernel, the kernel sought to the relevant disk sector and read the remaining bytes to fill the end of the buffer, instead doing the job asynchronously. This has caused disk head seek storms and very inefficient write performance (it can be reproduce with other file systems as well). We don't know yet if this is a bug or feature in the Linux kernel. This release candinate aims to solved the above problem, hereby greatly improve related performances. For example unpacking the Linux kernel source tree (21,000+ files) is usually 3-6 times faster now, depending on the hardware. Please note that this fix can't decrease the CPU usage. In fact, just the opposite. Beforehand the time was spent waiting for the slow disk I/O. By eliminating most of the disk seeks now, the CPU can achieve more useful work which will result higher CPU usage. Of course that will be improved too at some point in the future. The benchmarks are done on Linux, the performance impact is not known on other OSes but it should not be worse. This speed enhancement wouldn't have happened without David Fox's continuous help from week after week. Thank you David! Concurrent write performance is improved as well, moreover the performance of writing multi-GB size files, especially after the creation of thousands of other files. This only helps if the disk space is defragmented (file level defragmention is not enough). As far as we know, there is no free utility which could do this, so we plan to release one in the near future. The release candidate is available at http://ntfs-3g.org/ If no problem will be reported then the next stable release will be made earliest on late Wednesday, UTC. Please test intensively. Here are some help how one can do it without Windows and without [using] existing NTFS partitions, http://ntfs-3g.org/quality.html#howtotest Thank you for your attention and support, Szabolcs ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/