Slashdot Mirror
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?"
"It's too bad that stupidity isn't painful." - Anton LaVey
"Though I still wonder: If it is not meant to replace HFS+, could there be any other reasons to support ZFS?"
Duh... It's called compatibility.
Never ask for directions from a two-headed tourist! -Big Bird
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!
Going off on a tangent, it's a little funny that everyone is always going on about how "free" the GPL is, and yet ZFS is open-source, but not useable by Linux because of the GPL. I'm liking the BSD license more every day.
That said, there's zero chance (IMO) that Microsoft would add ZFS to Vista. They already dropped their transaction-based filesystem in order to get Vista out the door this decade. Adding ZFS support (much less using it as the default or recommended FS) would simply take too long, even if Apple had announced support a year ago.
It sounds good, but I think migrating for it just a tad extreme given that it will be implemented for Linux pretty quickly. We're talking about neat new features here, it'll re-enforce or make easier backups and redundancy, but it's not a to-die-for solution that will solve all your problems. There's no way I'd drop a fully configured server installation which does what I need for a new filesystem.
By the way it's nice to see dtrace, open source Java, and now ZFS coming out of Sun recently. I almost feel sorry for how little they get out of a lot of their innovations, they remind me of Bell Labs just before they died.
// MD_Update(&m,buf,j);
Wouldn't that pose a problem for mmap?
I think it would pose a problem for secure deletes. Try to obliterate a file by overwriting it with garbage, you end up writing somewhere else instead? Would the next overwrite attempt get the original location or would you have to write enough garbage to cycle over all the free space of the volume? Considering how large these volumes can get, that's a lot of boiled oceans for a multi-pass secure delete.
Oh, say does that Star-Spangled Banner entwine / The myrtle of Venus with Bacchus's vine?
Indeed, we may see Mac OS X Server supporting default ZFS before Mac OS X proper. It would make sense to deploy it first in a limited market with technical expert users as your target market.
The Rise and Fall of Online Community
But RAID 5 and 6 are both capable of verifying the primary data source against the parity data and transparently correcting errors that occur on less than the critical number of disks.
:)
With RAID-5, as with RAID-1, the critical number of disks is one. RAID-5 cannot transparently correct errors that occur on even a single stripe, unless you know a priori which stripe is affected.
With RAID-6 you can automatically correct errors that occur on a single stripe, but it still does not automatically detect such errors on read the way ZFS and RAID-Z do.
Or, you know, a checksum.
That's a great idea. Too bad those ZFS guys didn't think of it. Oh, wait.
Have you read the link I posted? It is getting old to keep repeating Jeff Bonwick's arguments when you can just read what I already pointed you to.
The underlying hardware will not necessarily notice errors. Hard drives are only designed to error protect the magnetic domains on the disk. There are all sorts of other places in the increasingly long datapath to disk where data can be lost, and, in fact, routinely does get lost.
The choice to verify every read is purely an implementation decision
RAID-6 does not verify every read because it is a stupid way to achieve data integrity. It wastes two thirds of your aggregate IO read bandwidth when you can just use checksums virtually for free. CPU cycles for checksumming is dirt cheap whereas IO bandwidth is extremely expensive.
I was just arguing the novelity you seem to think ZFS has -- using checksums to verify data integrity is not exactly cutting-edge computer science.
Yet strangely there aren't any other widely available storage solutions that provide transparent data integrity from the filesystem down.
I just don't think this particular feature is unique or superior to other available solutions for the same problem.
Then name another one. I think we've already shown that vanilla RAID does not qualify.
Don't any of you guys use Macs?
.Mac? ZFS enables all kinds of coolness and I, for one, can't wait to get it on my laptop.
Here are five good reasons for Apple to go to ZFS:
-No more Disk Warrior. The entire data store is self-validating. No bit rot.
-No RAID controllers needed: ZFS gives you fast RAID for free. Just add drives. Why would anyone care? See #5.
-No more volumes and, therefore, no more volume management. ZFS eliminates the whole volume concept. Add a disk to your system and it joins your storage pool. More capacity. Not more management. What home user would want that?
-Continuous Data Protection out of the box. Time Machine could give you a view of your data every time you update a file.
-ITV, or whatever it is going to be called. Multi-GB files that each cost $10-20, that can't be backed up - thanks DRM! - and therefore need a cheap and highly reliable RAID. ITV, two firewire drives, ZFS and you are in business.
-Not to mention the existential pleasure of having great technology that Vista doesn't have. In fact, since consumer technology is driving the enterprise, expect ZFS on Mac to raise the bar for every OS and file system.
I suspect that Time Machine is simply the first of several beautifully designed storage utilities that we'll see on Leopard. How about automatic synchronization when you plug in an external drive? Snapshots automatically exported to
Read more at ZFS On Leopard: How Cool Is That? Means, Motive & Opportunity: Apple Kills the Media Center PC and the latest ZFS On Mac: Now All-But-Official.
And you heard about the native iSCSI support in Leopard, right?