** EXECUTIVE SOFTWARE PRODUCT NEWS ** Diskeeper and Master File Table (MFT) Fragmentation It's been said a number of times that MFT fragmentation can considerably slow performance. Let's take a closer look at why this is so, and how Diskeeper restores performance lost to MFT fragmentation. The Master File Table (MFT) is the heart of the NTFS file system. It is essentially an index to all of the files on an NFTS volume, containing the file name, a list of file attributes, and a pointer to the file. The data for each file is contained in one record in the MFT, called the "file record". If a file is fragmented, then more than one pointer is required - one for each fragment, in fact. When the file system accesses a file, it must first go through the MFT to obtain the location of that file, or the location of that file's various fragments, as well as that file's various attributes. As one might surmise, an added MFT performance barrier occurs just due to regular file fragmentation. In that the file system must access the MFT and obtain the location of every single file fragment AND THEN locate the file fragments themselves, there is a lot of "double work" involved. But how does the MFT itself get fragmented, and what can be done about it? First, it should be said that NTFS has a built-in feature which, under some conditions, prevents MFT fragmentation from occurring. The MFT is created with a pre-allocated expansion space into which it can expand without fragmenting. There are a couple of conditions, however, under which MFT fragmentation does occur, one of them being very common. Converting FAT to NTFS The most common way the MFT gets fragmented is when a FAT partition is converted to NTFS. A FAT partition is converted to NTFS when such a conversion is needed or desired, but it also occurs automatically during Windows NT installation, if the NTFS format is chosen. The partition created during installation is a FAT partition, and even if the NTFS format is chosen during installation, the partition is still created as FAT, and only converted to NTFS after the first boot. When a FAT partition is converted to NTFS, an MFT is created. If there is a large enough contiguous free space, the MFT is made contiguous, with contiguous pre-allocated expansion space. However, since the MFT itself plus the pre-allocated expansion space comprises about 12% of the partition, there is usually not enough contiguous free space and the MFT is created fragmented. Full or Heavily Fragmented Disks or Partitions We covered the subject of the MFT's pre-allocated space above. There is a caveat to the MFT pre-allocated space, however. NTFS, having been developed to efficiently use every bit of space on a disk or partition, will utilize the pre-allocated MFT space for normal files if the disk or partition becomes full or heavily fragmented. Simply said, if the disk runs out of regular space for files or file fragments, NTFS will turn to the MFT's pre-allocated space and begin writing files and file fragments to this space. When this occurs, the MFT can only expand by continuing its growth in another space on the disk, a space not adjacent to the MFT. Thus MFT fragmentation begins, as when that space runs out, another space will have to be found, and so on. Effect of MFT Fragmentation on Performance When the MFT is fragmented, access to directories and files slows down tremendously as the file system works its way through the fragmented MFT to access the pointers and file attributes necessary to access every file. Combined with regular file fragmentation, this is a performance nightmare - the file system has to make multiple I/Os to access the MFT, AND THEN multiple I/Os to access the file itself. Before Diskeeper 5.0, there was no way to safely defragment the MFT, as it is not safe to move online, while the disk or partition is live and in use. Hence, one could defragment a disk or partition and clean up regular fragmentation, but MFT fragmentation would remain. (The author has personal experience with a medium-used disk which was regularly defragmented, yet ended up with an MFT in over 9,000 fragments. Before Diskeeper 5.0, nothing could be done about it, and simply opening Windows Explorer would take two to three minutes.) Frag Guard(r) to the Rescue With Diskeeper 5.0, MFT fragmentation is no longer a problem. With Diskeeper's Frag Guard feature, the MFT will be PREVENTED from fragmenting. For the first time, a defragmenter has taken a proactive approach to eliminating fragmentation. Put Diskeeper, with its new performance-boosting Frag-Guard feature, to work on ALL your Windows NT systems! Contact your reseller for best pricing.