On Thu, 2008-10-16 at 04:12 -0400, rektide wrote: > Hello all, > > I recently checked out btrfs and have started putting it through its > paces. I tried a raid10 and then a raid1, as so: > > mkfs.btrfs -m raid10 -d raid10 /dev/sda5 /dev/sdb5 /dev/sdc5 /dev/sdd5 > > and > > mkfs.btrfs -m raid1 -d raid1 /dev/sda5 /dev/sdb5 /dev/sdc5 /dev/sdd5 > > > In both cases after mounting /dev/sda5 /mnt, df -h reported 4 * > partition size. Is df lying, or is replication not happening right > now? df is lying. The total bytes in the FS include all 4 drives. I need to fix up the math for the total available space. > I also noticed that when I copied a file on to /mnt, I had to > sync before the available file size was affected. You mean in df? The delayed allocation accounting should be taking care of that, I'll take a look. > Also, I did not > read or write much, but only the first two disks /dev/sda5 and > /dev/sdb5 had their access lights going while I was using -m raid1 and > -d raid1. Is there any case where the third and fourth disks would be > used with -m raid1 -d raid1? > Yes, it allocates in chunks of about 1GB. So if you wrote more than 1GB, the next two drives would have been used. > > I've been writing Copy-On-Write software for a while now and believe > strongly that it is "the right way" to do almost all data operations. > There are manifest benefits in the filesystem domain for users, and am > glad to see such an amazingly slick & easy to use competitor appear on > the scene. I look forward to btrfs becoming disk format stable so I > can more wholeheartedly embrace it. > > > I spent quite a few hours late last night playing with Linux raid10 > and ext4; setting stride and stripe sizes. Tonight I briefly toyed > with btrfs and found it to be a far more pleasurable experience, and I > got considerably higher performance metrics (using simple bonnie++ > pleasurements). My CPU usage is considerably higher, but I find that > I dont mind that knowing there is real consistency checking ongoing. > > > Thank you all for this great effort. Thanks for giving things a try and sending along these notes, I'm glad it worked well for you. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
