<div>Final results FYI in this investigation: A recent Ubuntu release gets past the 1TB limit. I found binaries for dosfstools_2.11-2.1ubuntu3 at <a href="http://packages.ubuntu.com/feisty/otherosfs/dosfstools">http://packages.ubuntu.com/feisty/otherosfs/dosfstools</a> and unpacked them with ar -x. The source is in <a href="https://launchpad.net/ubuntu/+source/dosfstools/2.11-2.1ubuntu3">https://launchpad.net/ubuntu/+source/dosfstools/2.11-2.1ubuntu3</a> </div> <div>With 4KB sectors, it defaults to 128KB clusters and reaches over 97% write speed on an 8TB volume. The ramdisk area needed is a little over 512MB, so if you use 768MB you get quite a bit of room for directories also on ramdisk, and with a little finesse you can even make the subdirectories lay themselves down on ramdisk. To be "Windows-legal" you could use 32KB clusters and a little over 2GB ramdisk (or a little over 1GB with one FAT). Linux is happy with the big clusters, and according to the design should actually be willing to go to 16TB. Larry</div> <div> </div> <div>On 5/13/08, Stuart D. Gathman <<a href="mailto:stuart@bmsi.com">stuart@bmsi.com</a>> wrote: <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Tue, 13 May 2008, Larry Dickson wrote: > on the full, unpartitioned lv. Then it mounted, with the entire FAT on > ramdisk, and wrote very fast because FAT32 (like DOS) lays down data in > order from the start of a disk and does not skip around (I'd be interested > if anyone knows any other file systems with that property). The SysV filesystem put a fixed size inode table at the beginning of a partition. More modern filesystems from ext to reiser try to distribute the meta-data to keep it closer to the data. This is, of course, counter productive when the beginning of a disk is significantly faster and seek-free as in your setup. Since ext3 inode placement is table driven (with the table in a magic inode), there is probably a simple patch to mke2fs to create only one inode table at the beginning of a drive. In fact, I wonder if there is already an option... looks like -g blocks_per_group might do the trick - assuming inodes are at the beginning of a block group, rather than the middle. If not, a patch to mke2fs is needed to do what you want. -- Stuart D. Gathman <<a href="mailto:stuart@bmsi.com">stuart@bmsi.com</a>> Business Management Systems Inc. Phone: 703 591-0911 Fax: 703 591-6154 "Confutatis maledictis, flammis acribus addictis" - background song for a Microsoft sponsored "Where do you want to go from here?" commercial. _______________________________________________ linux-lvm mailing list <a href="mailto:linux-lvm@redhat.com">linux-lvm@redhat.com</a> <a href="https://www.redhat.com/mailman/listinfo/linux-lvm">https://www.redhat.com/mailman/listinfo/linux-lvm</a> read the LVM HOW-TO at <a href="http://tldp.org/HOWTO/LVM-HOWTO/">http://tldp.org/HOWTO/LVM-HOWTO/</a> </blockquote></div>