ZEVO Solution for ZFS on OS X Acquired by GreenBytes

[macharborguy]

I really like the ideas behind ZFS overall. Like the fact that ZFS looks at all of your storage as potentially useful for something other than "here is where my file is".

We really need to break away from the idea of a file system having this one-to-one relationship with the file browsing system (Finder, Explorer, etc). Just because I put 1 copy of a photo in my Photos folder, that doesn't mean there should only be 1 copy on the whole hard drive. Toss some extra copies around the free space further down the disk to use a backups (or on separate disks in the case of RAID-Z).

Another nice features is 'dedupe' which will try to save you on storage. Example, i do amateur web design and my hard drive is full of tons of backups of different websites, each one a wordpress blog. Most of the files in these wordpress directories are identical to eachother. Rather than having 10-100 copies of wp-login.php, it could just have 1 (plus 2 or 3 redundant copies spread around the drive) and have 10-100 references to that file.

The file system overall shouldn't simply be this thing that you dump files into and all it does is keep a record of where they are located on the drive. It needs to be active in keeping the files save, redundant, and ready to be moved in case of a bad sector. Its the difference between a filing cabinet and a secretary or archivist.

 

[ChrisA]

That was the whole reason I wanted to go Mac mini was that I would still get a good CPU and sip power (11W idle IIRC). If I wanted to throw a video on it for Handbrake to process overnight it would still be OK. Atom doesn't really offer that, nor a NAS-solution.

Is there any way to virtualize FreeNAS under OSX? Is that even a good idea?

You don't have to. FreeNAS is just Linux which is basically a UNIX-like OS. Mac OS X is already Unix. There is no need to "virtualize" anything. Mac OS can already serve files and uses about the same software that runs in the Linux based server.

Actually, if you have some spare Apple hardware around, maybe an old PPC mini. It can run Linux and would make a great server

 

[dolphin842]

You don't have to. FreeNAS is just Linux which is basically a UNIX-like OS. Mac OS X is already Unix. There is no need to "virtualize" anything. Mac OS can already serve files and uses about the same software that runs in the Linux based server.

Actually, if you have some spare Apple hardware around, maybe an old PPC mini. It can run Linux and would make a great server

FreeNAS is based on FreeBSD, not Linux, so it's actually closer in heritage to OS X than Linux. However, you can't just 'run' FreeNAS: It's a full FreeBSD OS distribution, so you'd have to virtualize it. You can't just pick out the FreeNAS-specific stuff and run it as-is on top of OS X.

Also, Linux usually doesn't run ZFS natively (i.e. in the kernel) due to licensing restrictions.

 

[gbytes1]

What is ZFS on OSX good for?

Greenbytes focus has been real time block level deduplication inside ZFS.
Greenbytes has developed technology which makes this fast and reliable.

I might imagine that 5 to 10x the usable storage on a MacBook SSD might
Be an attractive feature....stay tuned

 

[AidenShaw]

I might imagine that 5 to 10x the usable storage on a MacBook SSD might be an attractive feature....stay tuned

Those numbers are absurd.

A stock MacBook and apps might see a few percent savings with de-dupe. (There's one copy of Apple OSX, and one of each app.)

If one typically cloned photo or video libraries, the clones would take virtually no space until the clone is modified.

But "5x to 10x" is absurd.

 

[till213]

I'm not sure this is true; Time Machine for example only copies files that have been updated since the last successful backup (if any). It doesn't recheck files that it doesn't think have changed, so any corruption won't be backed up.

Okay, okay, so I was hyperventilating a bit You're absolutely right off course!

However assume that the bits flip during a write operation - then the file becomes corrupted on your disk and the time stamp changes. Causing Time Machine to backup it in the next cycle... so I am also not totally off with my claim

The problem is that your backup drive(s) could be suffering similar corruption, which means that even if your original copy is fine, the backed up copy could have become corrupted.

And I did not even mention that scenario...

Anyway, my point being that a file that's become corrupted will only be backed up if you were to successfully open it (in spite of the corruption) then re-save it with the corruption still in place. Even then Time Machine's historic data may save you.

It's no alternative to proper integrity checking and additional error correction, but your backups should be comparatively okay.

Off course you can go back in backup history for a particular file. But chances are if one file has become corrupted that other files have become corrupted and backed up since a long time! So you cannot simply "go back one week" (the time span where you found a good copy of that file you noticed went corrupt) and restore that entire state of your backup.

You would need to find the earliest point in time were "silent corruption" started. And that's a lot of pain...!

 

[Koppenhoefer]

I run a FreeNAS box (uses ZFS as the filesystem). It offers AFP network shares (and can even advertise specific datasets as compatible with Time Machine)..

Hello.. Are you able to use that AFP share for NetworkHomeDirectories and/or PortableHomeDirectories for 10.8 OS X (Mountain Lion) users? I'm concerned that ZFS doesn't play well with the Library/ folder?

 

[dolphin842]

Hello.. Are you able to use that AFP share for NetworkHomeDirectories and/or PortableHomeDirectories for 10.8 OS X (Mountain Lion) users? I'm concerned that ZFS doesn't play well with the Library/ folder?

I've never used networked home directories (either with HFS+ or ZFS) so I'm not sure. That said, if you browse the Zevo forums, you'll find that using ZFS for a home directory results in some cosmetic issues (e.g. custom icons not displaying). Serving ~/Library over AFP might or might not mask that behavior.

 

[grahamperrin]

Source code for ZEVO following acquisition by Oracle

Just for the record: around two weeks after Oracle announced its intention to acquire GreenBytes, I made an enquiry about source code. Addressed to someone at GreenBytes … but then the same day (2nd June), the acquisition completed.

GreenBytes' technology "is expected to enhance Oracle's ZFS Storage Appliances" – so I don't expect Oracle to develop ZEVO for OS X. Still, I hope that something good can be done with at least some of the code.