On Thu, Apr 03, 2008 at 06:19:04PM +0200, Paul Slootman wrote: > Hi, > I wanted to try out ext4 on my shiny new 9+TB RAID5 device > (11 x 1TB disks in md raid5). > > I obtained the 1.39-tyt3 version of e2fsprogs, and did: > > ./mkfs.ext3 -j -m 0 -N 1000000000 -O dir_index,filetype,resize_inode -E stride=65536,resize=5120000000 -J device=/dev/mapper/vg11-md15--journal -L data2 /dev/md15 > > (If using a separate device for the journal is inadvisable, please let > me know; this is on a different set of spindles that md15 is running on.) > > The stride was calculated from the 64k chunk of the raid5 device. > Mainly a guess, as I couldn't find any clear reference on how to plug in > the values to fill this in. The stride parameter is the problem. Newer versions of e2fsprogs don't allow a stride parameter which is too big. If you want to do the perfect calculation, you take the 64k chunk size, and divide it by the 4k blocksize to yield a stride parameter of 16. Actually, though, simply using a non-zero stride size is actually good enough --- and if you have a even number of RAID-5 disks, you might not need this parameter at all. (It's only purpose is to perturb the location of the block bitmaps so that all of the bitmaps don't end up on a single hard drive.) BTW, we will be making a new snapshot for people who want to test ext4 soon.... - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
