Personal Update: I’m taking some time off from daily posting until January 2nd, 2007, much to Ms. Mojo’s relief. There may be some things I just can’t resist. Just don’t expect daily posts. Cheers,


I did a post on the /. Apple forum and got back an interesting response from someone who, IMHO, is test driving some FUD for their employer. Smart, articulate and close enough to the truth to know better. This is the opening of another front in the war to marginalize ZFS, Apple and Sun.

Here is the their original response. They responded to my bullet points, which are included in the quote, and then my response to each point is inserted between the quote sections.

I flamed more than I usually do. There must be something about those /. forums that bring out the beast in me.

Re:Good Reasons To Support ZFS on Mac
by Junta (36770) on Tuesday December 19, @12:53PM (#17304700)
-No RAID controllers needed: ZFS gives you fast RAID for free. Just add drives.

Not particularly new, systems have been fast enough for general software raid for a long time. ZFS has the opportunity to leverage FS-level knowledge to milk some efficiency out of things that block-level approaches cannot, but ultimately ZFS isn’t obsoleting the need for RAID controllers any more than software RAID already has. I admit that there are a lot of proprietary RAID controllers employed where they shouldn’t be, but that’s not a technical problem, it’s a perception problem, ZFS won’t fix that.

Hard to know where to start. Do you work for Microsoft? You aren’t stupid, and are well-written, so I won’t sugar coat this.

ZFS RAID: ZFS does full stripe writes, all the time, which are the fastest software RAID writes, thanks to variable stripe writes. This does, in fact, obsolete mid-range HW RAID.

-No more Disk Warrior. The entire data store is self-validating. No bit rot.

ZFS doesn’t mandate the storage pool be implemented in any particularly redundant way. If you have just one drive, it’s fairly obviously non-redundant. If you add a second drive, it may or may not be a mirror of the first one, depending on how each was added to the pool. Every indication I have seen shows that ZFS checksumming helps detect data integrity errors, and does not implement ECC. It detects block-level silent data corruption, and if the pool is configured just so, the subsystem can reroute things and alert user to service need. If Apples always ship with two drives, it could get clever, but it isn’t magical.

Self-validating the data store is independent of RAID. If you don’t understand this, it is back to school time. File systems are supposed to be independent of the underlying infrastructure.

-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.

For the most part ZFS simplifies it, but not all storage will be wanted in the pool. One shining long term example is removable media (optical and flash). Another is so far, even Sun hasn’t figured out how to boot from it, so you will have some volume management still, just adding an external hard disk can be made much much easier than under Linux or Windows.(New uninitialized device detected, add to (cute volume name) or…

Apple engineers can figure out how to boot from it. Not a priority for Sun, whose E10K’s required an internal SCSI disk for years to boot.

-Continuous Data Protection out of the box. Time Machine could give you a view of your data every time you update a file.

ZFS as far as I can see is not a versioned filesystem where every single modification is tracked. It has built-in snapshotting functionality, and therefore makes an easy way to implement time machine backend (or at least offloaded to Sun to sweat the details instead of Apple), perhaps even lower impact at snapshotting time than Time Machine’s current implementation, but it won’t continuously track changes.

Versioning isn’t the same as CDP, as you well know. Since snapshots in ZFS are cheaper than overwrites, it would be simple – and I have no idea what APPL engineers are implementing – to snapshot before every ~Documents write. And your point is???

-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 enough details are available to ascertain how it will work, but while the savvy get the point (my Myth setup separates backend and frontend to have more robust, but noiser measures to protect stuff), by and large mass-market set top boxes get away without redundancy.

Today’s set-top boxes aren’t hoping you will spend thousands of dollars purchasing copies of content that they won’t let you back up. ITV is. So Apple is suddenly going to offer a generic set-top box? WTF?

-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.

ZFS on Mac will likely do little to nothing to raise the bar in the enterprise beyond Solaris doing it. I admit ZFS is the one nugget Sun has brought out for Solaris that has me curious, but OSX’s embracing it didn’t extend it more. ZFS is among their biggest assets, and they clearly want either revenue or Solaris acceptance from it (hence licensing that precludes it from linux, their primary competitive solution). I think someone was on to something when they discussed the Sun/Apple relationship long term. Solaris, *particularly* thanks to ZFS can perform server-side tasks competently and still has some mindshare. Solaris workstations, however, are largely considered unneeded and counter-productive in ease of use nowadays. Apple has not captured server mindshare (and in fact makes crappy server products hardware wise relative to the competition including Sun), but no one argues that OSX is too hard to be a desktop/workstation system (though maybe lacking critical application support)…. To date Apple has been fairly hands-off about ‘solutions’ involving other platforms (i.e. windows and linux). They’ve tried to do servers but ultimately their marketing image doesn’t align with that part of the market even if they did put together a competent hardware platform. If they did ally with Sun to try to push into the professional space, it *could* be interesting, if not too late for Sun at least.

You don’t know a frikkin’ thing about technology diffusion, do you? A hint: when you get hundreds of thousands of people going to work and telling the CIO that my home system does this and this and your expensive proprietary system doesn’t, that raises the bar. Remember when PC’s and VisiCalc were new, and smart guys would rip IT a new one because their batch IBM 4300s couldn’t respond as quickly as a $3k PC? No bells ringing?

Apple doesn’t care about the enterprise. The enterprise is the elephant’s graveyard of IT companies. The enterprise is coming to Apple, and companies like Apple, not vice-versa.

Comments welcome, as always. Flame bait won’t be published. Serious comments only, please. Moderation on to deflect comment spam.