Let's be a little more precise here. Mac OS X certainly CAN fragment. It's just that the operating system (independent of what filesystem you're using) automatically de-fragments files on the fly. Any time a file is opened, the system runs down a short checklist (is the file smaller than 20 MB, does the file have more than 8 extents on the disk, is the file not read-only) and if it passes, Mac OS X relocates the file's blocks to a contiguous part of the disk automatically. That is, it de-fragments it.Why the 20 MB limit? Two reasons. First, any file bigger than 20 MB probably won't give you a problem if it's fragmented. You'll be reading data from it in such big chunks that the extra seeks won't be harmful. Second, relocating a very large file would cause a spike in disk I/O that can slow the system down, particularly on a laptop.So typical users don't need to worry about file fragmentation at all, period. If you have a very specific application, you might; say if you're doing a ton of video I/O. But that's rarely a problem these days, as I/O hardware is fast enough that it can sustain playback of compressed (DV or HDV or DVCPRO-HD) video even if it's pretty well fragmented.
You can't boot ANY computer off of a ZFS filesystem right now.Besides, the really cool stuff in ZFS will help you more with user storage than with your root partition. In fact, this might be enough to take us back to the days of a small boot partition just for /System with the rest of the disk being dedicated to a ZFS storage pool. If you run out of space on your first internal drive, you can just pop in another, add it to the pool, and keep working without having to think about what lives on which disk.(Not having worked with ZFS, I have no idea how it handles a failed disk in a non-RAID, non-mirrored storage pool. I expect it would be completely disastrous.)
Here's my favorite quote from Sun's ZFS project leader on the subject (with a little extra detial):ZFS is a 128-bit file system, which means it can store 18 billion billion (18 quintillion) times more data than current 64-bit systems. The limitations of ZFS are designed to be so large that they will never be encountered in practice. Project leader Bonwick said, "Populating 128-bit file systems would exceed the quantum limits of earth-based storage. You couldn't fill a 128-bit storage pool without boiling the oceans.Fantastic! It's this type of radical thinking that companies like Microsoft need a good dose of. I'm glad Apple is fully aware of ZFS.
@guitarhcp:My sister is in interior design and would gladly explain about different blacks to you... sadly I'm in computer science and I tend to think more like you. Just accept that we're wrong on this one and there are different kinds of black, you don't really want to hear about it.
Anyone know if it is a case-sensitive filesystem or not? Many OSX apps fail to run if you use the case-sensitive version of HFS+. Adobe Acrobat being one of them...
all it takes is an initramfs to boot into the ZFS. It's not that hard to do. So most likely, if Apple is going to use ZFS, it *will* be for both "bootable" and non-bootable drives. I put "bootable" in quotes because, again, it's being "booted" from the initram fs rather than straight from the EFI.
hypercryptDec 17, 2006
<a class="user" href="http://en.wikipedia.org/wiki/ZFS">http://en.wikipedia.org/wiki/ZFS</a>
maxplanarDec 17, 2006
My guess is that ZFS will first come to OSX as a supported filesystem for non-boot drives. Boot support isn't there yet in ZFS, AFAIK.
guitarhcpDec 17, 2006
Not to be an ass....but how could it *not* be the same black?
anonym41414Dec 17, 2006
Let's be a little more precise here. Mac OS X certainly CAN fragment. It's just that the operating system (independent of what filesystem you're using) automatically de-fragments files on the fly. Any time a file is opened, the system runs down a short checklist (is the file smaller than 20 MB, does the file have more than 8 extents on the disk, is the file not read-only) and if it passes, Mac OS X relocates the file's blocks to a contiguous part of the disk automatically. That is, it de-fragments it.Why the 20 MB limit? Two reasons. First, any file bigger than 20 MB probably won't give you a problem if it's fragmented. You'll be reading data from it in such big chunks that the extra seeks won't be harmful. Second, relocating a very large file would cause a spike in disk I/O that can slow the system down, particularly on a laptop.So typical users don't need to worry about file fragmentation at all, period. If you have a very specific application, you might; say if you're doing a ton of video I/O. But that's rarely a problem these days, as I/O hardware is fast enough that it can sustain playback of compressed (DV or HDV or DVCPRO-HD) video even if it's pretty well fragmented.
anonym41414Dec 17, 2006
You can't boot ANY computer off of a ZFS filesystem right now.Besides, the really cool stuff in ZFS will help you more with user storage than with your root partition. In fact, this might be enough to take us back to the days of a small boot partition just for /System with the rest of the disk being dedicated to a ZFS storage pool. If you run out of space on your first internal drive, you can just pop in another, add it to the pool, and keep working without having to think about what lives on which disk.(Not having worked with ZFS, I have no idea how it handles a failed disk in a non-RAID, non-mirrored storage pool. I expect it would be completely disastrous.)
irelandDec 17, 2006
Here's my favorite quote from Sun's ZFS project leader on the subject (with a little extra detial):ZFS is a 128-bit file system, which means it can store 18 billion billion (18 quintillion) times more data than current 64-bit systems. The limitations of ZFS are designed to be so large that they will never be encountered in practice. Project leader Bonwick said, "Populating 128-bit file systems would exceed the quantum limits of earth-based storage. You couldn't fill a 128-bit storage pool without boiling the oceans.Fantastic! It's this type of radical thinking that companies like Microsoft need a good dose of. I'm glad Apple is fully aware of ZFS.
nofxjunkeeDec 17, 2006
@guitarhcp:My sister is in interior design and would gladly explain about different blacks to you... sadly I'm in computer science and I tend to think more like you. Just accept that we're wrong on this one and there are different kinds of black, you don't really want to hear about it.
diggeasytigerDec 17, 2006
no : <a class="user" href="http://en.wikipedia.org/wiki/Virtual_file_system">http://en.wikipedia.org/wiki/Virtual_file_system</a>
elranzerDec 17, 2006
Anyone know if it is a case-sensitive filesystem or not? Many OSX apps fail to run if you use the case-sensitive version of HFS+. Adobe Acrobat being one of them...
diggapleazeDec 17, 2006
all it takes is an initramfs to boot into the ZFS. It's not that hard to do. So most likely, if Apple is going to use ZFS, it *will* be for both "bootable" and non-bootable drives. I put "bootable" in quotes because, again, it's being "booted" from the initram fs rather than straight from the EFI.
geekoidNov 8, 2007
Black is the absence of all colour. There is only one black. All others are shades of grey.