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ZFS Shows Up in New Leopard Build
Udo Schmitz writes "As a follow-up to rumours from May this year, World of Apple has a screenshot showing Sun's Zettabyte File System in "the most recent Build of Mac OS X 10.5 Leopard". Though I still wonder: If it is not meant to replace HFS+, could there be any other reasons to support ZFS?"
Now that Vista is finalized, expect Apple to show more and more of the 'secret' features of leopard!
--jeffk++
ipv6 is my vpn
Because if Apple showed them before, there was a risk that Microsoft tried to announce them as future features in their soon-to-be-released perfect Windows Vista ?
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
I will be soon converting my Linux server to Solaris just for ZFS. Although ZFS may not terribly useful on a normal desktop, on a server, it's very powerful.... The idea of parity data actually being used actively to ensure data isn't corrupted is brilliant imho. So is the idea of on-the-fly recovery (I remember a video of some guy writing 30 megs of junk to a partition using dd, ZFS detecting it, and repairing it). *ends rant since all this can be read up about online*
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- They had implemented everything I thought they should, and
- That only accounted for about 40% of the features of ZFS.
Calling it the last word in filesystems might be hyperbole, but I expect ZFS to last a good 10-20 years, which is quite respectable for a filesystem, and I wouldn't be surprised if it lasted longer. Is it a replacement for HFS+? Not yet.HFS+ is a very nice filesystem for single user systems with a single disk. It implements journalling, has reasonable performance, and has good metadata support. For the average users at the moment, the only real advantage of ZFS would be snapshots, and these are not too difficult to implement for other filesystems.
ZFS, however, is much better when you have multiple physical disks. At the moment, only the top-end Macs have more than one disk. This is likely to change in two ways:
- Cheap flash,
- Network storage
For a home user, ZFS could handle backups trivially by plugging in a large flash drive and adding it to the pool. I suspect this will be one mechanism Time Machine will use. Due to the way ZFS works, you can just mirror a part of the directory tree (e.g.ZFS is not needed as a replacement for HFS+ in 2007, but it probably will be in 2008-9. ZFS is a 128-bit filesystem, which means it is designed to last for a long time. We will probably never need a 128-bit filesystem (unless we actually want to build hard drives the size of planets with single-atom sectors), but we will need a 65-bit filesystem once we get to around 10 Exabytes. This won't happen with single drives for a while, but it will with RAID arrays.
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The tech behind ZFS at least sounds very impressive, but I have to wonder how useful it is for workstation drives.
I've never found plain-Jane posix permissions to be all that useful on anything other than the most basic of server environments.
HFS has going for it all the fun stuff we've come to love apple for, such as transparent file customization like icons, labels, meta data, and whatnot through resource forks. I assume that these can be made to work with ZFS by making hidden files.
What I'd really like to see is both that kind of functionality along with NTFS's really excellent ACL permission system implemented. ACL permissions are a godsend for people responsible for running a file store that's used by humans as opposed to automated processes. NTFS also has a great deal of capacity for meta-data, although not to the same level as HFS.
NTFS is one of the few worthwhile things that's ever come out of Redmond. I wish more people would spend a bit learning from it without throwing it away simply because it's MS bloat.
The next Slashdot story will be ready soon, but subscribers can beat the rush and slashdot the links early!
So it's about the snapshot ability of ZFS, and that's exactly what will be needed for Time Machine.
"I use a Mac because I'm just better than you are."
Mmap simple maps pages of a disk file into memory. If the disk file changes its physical location then the mapping is updated. When you call mmap, you give it a disk file, an offset, and an extent. It is up to the VFS layer to translate this into physical mappings. LFS has the same issues, and these were solved well over a decade ago.
If you invoke mmap with MAP_PRIVATE, this actually makes it easier; if someone else updates the file then you just keep the existing mapping.
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Wouldn't full NTFS support (or well, support for any FS more in use then ZFS today) make more sense?
Yeah, I mean it's not like NTFS is defined and controlled by an organization renowned for its hostility to other platforms, reluctant to document things in a way that other people can implement them, and scared of interoperability, is it?
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Zed's dead, baby.
Makes use of copy-on-write; rather than overwriting old data with new data, it writes new data to a new location and then overwrites the pointer to the old data
It may do, but like many things there are alternative approaches.
From working on embedded hardware with flash memory, this makes me wonder whether possible addition of ZFS is meant to be for flash storage? Let me explain: flash memory has a fairly limited write-count, relative to hard disks, so to compensate for this memory is written in a circular fashion, to ensure that a given sector is written the least often possible. In addition to this, from what I can tell, Apple's main sales point are low profile computers and portables. The latter would benefit from flash storage as means of extending battery life, even if it is for a certain elements, such as for the OS which is accesed far more frequently than anything else on disk. Given this I wouldn't be surprised to see flash memory in future models of Apple portables, using ZFS, while HFS+ is still used for the hard disks.
This is pure speculation, but I feel that it has a high probabilty of being near the mark.
Jumpstart the tartan drive.
I've been wandering about this and am insanely curious: if ZFS really does intelligently copy on write how far can it take it?
e tc.) then this could probably happen quite easily.
for starters, does the FS "know" that i've just clicked "Save As" in my word processor? what about copy and pasting a file back into the same directory to make a local copy? Also? is it just within variations on the same file? if i have a particular setup exe on my system but forget, and download it again to the desktop surely the FS has no initial way of knowing that they are one and the same, does some funky heuristic happen?
basically: does the OS's read/write/copy/delete functionality have to invoke copy-on-write via a FS API or is it built in for every single sector-sized chunk that gets stuffed into the FS?
the next question is the one in my subject: how therefore do you define "capacity"? if i've got a bunch of files that take up 700mb on a ZFS device and try to back up to a (Joliet) CD will i get a message telling me that the CD doesnt have room? i can imagine this scenario being unlikely with optimised binary data (jpegs and mpegs) but if i'm backing up a dev environment with autobackups (main.c,main.c.bak.001,main.c.bak.002,etc.) and manually created and dated directory tree "snapshots" (dev,dev_backup_2006-12-18,dev_backup_2006-12-01,
If you don't risk failure you don't risk success.
You both miss the point of HFS+ and ZFS. In Solaris ZFS has not replaced UFS. ZFS is an elegant way to manage large amounts of storage tied together with inexpensive and simple SATA drives. If you have one disk in your Mac, ZFS probably will not be your choice. HFS+ will work very well and be very easy to manage. A file server with 3 or 4 750 GB drives however, might be cut up so that part of the storage is mirrored for safety, limited for certain uses, and spanned over drives for size. For example, 3 750's could be divided into 1 TB unmirrored storage, 250 GB mirrored, a temp area of up to 100GB and the rest (650+ GB depending on temp are usage) held in reserve. In addition ZFS does quite a bit of error checking on the data to avoid any possible corruption during reads. However, it will never replace HFS+ on an iMac for your average user.
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i'd hit it so hard, if you pulled me out you'd be the king of britain [bash.org]
Over past months, I've read a lot of people commenting on ZFS who have no idea what it is. What it is, is the next generation of filesystems, not a "tweak" of current fs technology. It just happens to "look like" an ordinary POSIX fs, from a distance (if you ignore the administration/pool stuff...) But inside, it's something new under the Sun, folks.
RAID experts don't grok it, because it does things RAID can't do (end-to-end).
Devotees of ext2fs, reiserfs (yay!), NTFS (LOL!), or HFS+ don't grok it, because none of those filesystems do what ZFS does.
Read about it before you write it off as old wine in a new bottle. To ask the question, "Does OS X need a new filesystem?" is a perfect example of missing the point. Once you've looked at what ZFS really brings to the table, you'll see why it's an inevitable future, sooner or later, and you'll stop looking foolish.
Some links I posted this week:
- http://www.osnews.com/story.php/16739/Screenshot-Z FS-in-Leopard
- http://mac4ever.com/news/27485/zettabyte_sur_leopa rd/
(older rumour http://www.osnews.com/story.php?news_id=14473)
For OS X people wondering why the fuss about ZFS - summaries include: - http://www.sun.com/2004-0914/feature/ - http://www.sun.com/bigadmin/features/articles/zfs_ part1.scalable.html
"Why ZFS for home": - http://uadmin.blogspot.com/2006/05/why-zfs-for-hom e.html
"Here are ten reasons why you'll want to reformat all of your systems and use ZFS.": http://www.tech-recipes.com/rx/1446/zfs_ten_reason s_to_reformat_your_...
And some more technical explanations from Chief Engineer: - http://blogs.sun.com/bonwick/entry/zfs_end_to_end_ data
- http://blogs.sun.com/bonwick/entry/smokin_mirrors
you had me at #!