Discussion:
maczfs / ZEVO
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Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
2013-02-15 16:08:27 UTC
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Anybody using maczfs / ZEVO? Have good or bad things to say, in terms of reliability, performance, features?

My main reason for asking is this: I have a mac, I use Time Machine, and I have VM's inside. Time Machine, while great in general, has the limitation of being unable to intelligently identify changed bits inside a VM file. So you have to exclude the VM from Time Machine, and you have to run backup software inside the VM.

I would greatly prefer, if it's reliable, to let the VM reside on ZFS and use zfs send to backup my guest VM's.

I am not looking to replace HFS+ as the primary filesystem of the mac; although that would be cool, there's often a reliability benefit to staying on the supported, beaten path, standard configuration. But if ZFS can be used to hold the guest VM storage reliably, I would benefit from that.

Thanks...
Tim Cook
2013-02-15 16:13:56 UTC
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On Fri, Feb 15, 2013 at 10:08 AM, Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris) <
Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Anybody using maczfs / ZEVO? Have good or bad things to say, in terms
of reliability, performance, features?****
** **
My main reason for asking is this: I have a mac, I use Time Machine, and
I have VM's inside. Time Machine, while great in general, has the
limitation of being unable to intelligently identify changed bits inside a
VM file. So you have to exclude the VM from Time Machine, and you have to
run backup software inside the VM. ****
** **
I would greatly prefer, if it's reliable, to let the VM reside on ZFS and
use zfs send to backup my guest VM's.****
** **
I am not looking to replace HFS+ as the primary filesystem of the mac;
although that would be cool, there's often a reliability benefit to staying
on the supported, beaten path, standard configuration. But if ZFS can be
used to hold the guest VM storage reliably, I would benefit from that.****
** **
Thanks...****
I have a few coworkers using it. No horror stories and it's been in use
about 6 months now. If there were any showstoppers I'm sure I'd have heard
loud complaints by now :)

--Tim
Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
2013-02-17 14:15:35 UTC
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Sent: Friday, February 15, 2013 11:14 AM
I have a few coworkers using it.  No horror stories and it's been in use about 6
months now.  If there were any showstoppers I'm sure I'd have heard loud
complaints by now :)
So, I have discovered a *couple* of unexpected problems.
At first, I thought it would be nice to split my HD into 2 partitions, use the 2nd partition for zpool, and use vmdk wrapper around a zvol raw device. So I started partitioning my HD. As it turns out, there's a bug in diskutility... As long as you partition your hard drive and *format* the second partition with hfs+, then it works very smoothly. But then I couldn't find any way to dismount the second partition (there is no eject) ... If I go back, I think maybe I'll figure it out, but I didn't try too hard ... I resized back to normal, and then split again, selecting the "Empty Space" option for the second partition. Bad idea. Diskutillity horked the partition tables, and I had to restore from time machine. I thought maybe it was just a fluke, so I repeated the whole process a second time ... try to split disk, try to make the second half "Free Space" and forced to restore system.

Lesson learned. Don't try to create an unused partition on the mac HD.

So then I just created one big honking file via "dd" and used it for zpool store. Tried to create zvol. Unfortunately zevo doesn't do zvol.

Ok, no problem. Windows can run NTFS inside a vmdk file inside a zfs filesystem inside an hfs+ file inside the hfs+ filesystem. (Yuk.) But it works.

Unfortunately, because it's a file in the backend, zevo doesn't find the pool on reboot. It doesn't seem to do the equivalent of a zpool.cache. I've asked a question in their support forum to see if there's some way to solve that problem, but I don't know yet.

Tim, Simon, Volker, Chris, and Erik - How do you use it?
I am making the informed guess, that you're using it primarily on non-laptops, which have second hard drives, and you're giving the entire disk to the zpool. Right?
Erik Ableson
2013-02-17 14:54:00 UTC
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Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Sent: Friday, February 15, 2013 11:14 AM
I have a few coworkers using it. No horror stories and it's been in use about 6
months now. If there were any showstoppers I'm sure I'd have heard loud
complaints by now :)
So, I have discovered a *couple* of unexpected problems.
At first, I thought it would be nice to split my HD into 2 partitions, use the 2nd partition for zpool, and use vmdk wrapper around a zvol raw device. So I started partitioning my HD. As it turns out, there's a bug in diskutility... As long as you partition your hard drive and *format* the second partition with hfs+, then it works very smoothly. But then I couldn't find any way to dismount the second partition (there is no eject) ... If I go back, I think maybe I'll figure it out, but I didn't try too hard ... I resized back to normal, and then split again, selecting the "Empty Space" option for the second partition. Bad idea. Diskutillity horked the partition tables, and I had to restore from time machine. I thought maybe it was just a fluke, so I repeated the whole process a second time ... try to split disk, try to make the second half "Free Space" and forced to restore system.
Lesson learned. Don't try to create an unused partition on the mac HD.
So then I just created one big honking file via "dd" and used it for zpool store. Tried to create zvol. Unfortunately zevo doesn't do zvol.
Ok, no problem. Windows can run NTFS inside a vmdk file inside a zfs filesystem inside an hfs+ file inside the hfs+ filesystem. (Yuk.) But it works.
Unfortunately, because it's a file in the backend, zevo doesn't find the pool on reboot. It doesn't seem to do the equivalent of a zpool.cache. I've asked a question in their support forum to see if there's some way to solve that problem, but I don't know yet.
Tim, Simon, Volker, Chris, and Erik - How do you use it?
I am making the informed guess, that you're using it primarily on non-laptops, which have second hard drives, and you're giving the entire disk to the zpool. Right?
Actually, my usage is with a laptop, but I've pretty much given up on doing anything serious in ZFS without going whole disk, so I hadn't run across the partitioning issues or the lack of ZFS.cache for mounting file based pools.

Back to the day to day usage. I'm using it primarily with my MacBook Air and I have Seagate GoFlex thunderbolt adaptor into which I plug SSDs holding VMs and sources. While on the move, I leave the external drive in my bag and use a 1m thunderbolt cable so I'm tethered to the bag, but it's usable.

Eventually, I'll probably get one of the StarTech 4 disk toaster docks on USB 3 for while I'm at the office, and continue to rely on the thunderbolt SSD while on the road.

On the partitioning front, after thinking a bit, you should be able to tell Zevo to use a second partition on the main disk. The trick would be creating the partition normally as an HFS+ volume, unmounting it with something like sudo diskutil unmount disk0s4, followed by sudo zpool create zevo disk0s4

Oh, other side notes I almost forgot. To ensure that you don't chew up all of your memory with ARC it's also a good idea to disable spotlight searching on ZFS volumes (sudo mdutil -i off /Volumes/Zevo)

Cheers,

Erik
Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
2013-02-18 11:59:35 UTC
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Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Tim, Simon, Volker, Chris, and Erik - How do you use it?
I am making the informed guess, that you're using it primarily on non-
laptops, which have second hard drives, and you're giving the entire disk to
the zpool. Right?
Perhaps it works fine for whole disks, or even partitions, but with my file-backed pool, the performance was terrible. Everything else I could work around ... lack of zvol, inability to import during reboot ... But the performance problem was significant enough for me to scrap it and go back to normal. Oh well.
Paul Kraus
2013-02-19 15:41:50 UTC
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Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Sent: Friday, February 15, 2013 11:14 AM
I have a few coworkers using it. No horror stories and it's been in use about 6
months now. If there were any showstoppers I'm sure I'd have heard loud
complaints by now :)
So, I have discovered a *couple* of unexpected problems.
At first, I thought it would be nice to split my HD into 2 partitions, use the 2nd partition for zpool, and use vmdk wrapper around a zvol raw device. So I started partitioning my HD. As it turns out, there's a bug in diskutility... As long as you partition your hard drive and *format* the second partition with hfs+, then it works very smoothly. But then I couldn't find any way to dismount the second partition (there is no eject)
When I have run into this (Mac OS X 10.6) I fall back to the command line... umount has worked just fine for me. NOTE: I was not doing what you are trying, I had an odd device mounted and I wanted to un mount it.

I often find that going to the command line on Mac OS X is very helpful, but since the GUI really is very well done for most (but certainly not all) tasks, I usually don't remember to go to the command line until after I have been beating my head against the GUI for too long :-(

--
Paul Kraus
Deputy Technical Director, LoneStarCon 3
Sound Coordinator, Schenectady Light Opera Company

Volker A. Brandt
2013-02-15 16:28:37 UTC
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Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Anybody using maczfs / ZEVO? Have good or bad things to say, in
terms of reliability, performance, features?
I use it on and off for data exchange between a MacBook Pro, some iMacs,
and various Solarisoid systems. I do this with single-disk pools on
external drives, connected via eSATA to Solaris servers and via USB to
the MacBook Pro.

It works.

There is just one outrageously brain-damaged idiocy, and that is
the installer. I have one iMac that only has 3 GB RAM. The installer
flatly refuses to install on that box because it insists on a minimum
of 4 GB. It cannot guarantee stable performance for a single-disk pool
with only 3 GB of memory. What a load of crap. If that had been the
first box I installed it on, I would have ditched it then and there.

I signed up to the ZEVO community forum and saw that other users had
already complained about that problem, but it seems neither an official
fix nor a workaround is available.

ZEVO is free, and Greenbytes are entitled to release it in whatever
form they want, but I found that restriction remarkably stupid.


Best regards -- Volker
--
------------------------------------------------------------------------
Volker A. Brandt Consulting and Support for Oracle Solaris
Brandt & Brandt Computer GmbH WWW: http://www.bb-c.de/
Am Wiesenpfad 6, 53340 Meckenheim, GERMANY Email: ***@bb-c.de
Handelsregister: Amtsgericht Bonn, HRB 10513 Schuhgröße: 46
Geschäftsführer: Rainer J.H. Brandt und Volker A. Brandt

"When logic and proportion have fallen sloppy dead"
Hearn, Christopher
2013-02-15 16:45:24 UTC
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On Feb 15, 2013, at 11:08 AM, Edward Ned Harvey (opensolarisisdeadlongliveopensolaris) <***@nedharvey.com<mailto:***@nedharvey.com>> wrote:

Anybody using maczfs / ZEVO? Have good or bad things to say, in terms of reliability, performance, features?

My main reason for asking is this: I have a mac, I use Time Machine, and I have VM's inside. Time Machine, while great in general, has the limitation of being unable to intelligently identify changed bits inside a VM file. So you have to exclude the VM from Time Machine, and you have to run backup software inside the VM.

I would greatly prefer, if it's reliable, to let the VM reside on ZFS and use zfs send to backup my guest VM's.

I am not looking to replace HFS+ as the primary filesystem of the mac; although that would be cool, there's often a reliability benefit to staying on the supported, beaten path, standard configuration. But if ZFS can be used to hold the guest VM storage reliably, I would benefit from that.

Thanks...
___________________

ZEVO's great as long as you don't mind managing everything from the command line. I had to figure out how to identify the disks, as it manages them a little differently in MacOS. I had some minor issues hosting iTunes/iPhoto libraries on ZFS volumes, with it being a little more sluggish & freezing up slightly. Other than that it worked fine. I'm back on HFS+ for iTunes/iPhoto now, but I'm hopeful it'll be resolved in a future release so I can switch back again.

MacZFS will give zpool version 8 & zfs version 2, whereas ZEVO is zpool version 28 &zfs version 5, so make your decision accordingly. I have not tried MacZFS in a long time, so I couldn't say if it is better or worse than ZEVO.

Chris
Erik Ableson
2013-02-15 16:58:01 UTC
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I've been using it happily since before the Greenbytes purchase. You're currently limited to pool version 28. I generally use it with external USB drives (single disk pools), but I have tested file based RAIDZ pools which worked fine.

The only caveat I will note, particularly for working with VMs (my primary use case as well) is that you can run into situations where the OS is RAM starved with the ARC filling up. I've run into cases where Fusion refused to boot up VMs claiming not enough memory after I was using another machine for a while. Ejecting the pool will generally clear out the ARC (allocated to the kernel) so that you can reinsert and then start the VM.

It's a full implementation as far as I can tell, including zfs send/recv so you can easily backup across the network without having the plugin your disks to the other server.

I'd put it in the reliable camp (at the very least more reliable that HFS+ or ExFAT on cheap 2.5" drives)

Cheers,

Erik
Post by Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
Anybody using maczfs / ZEVO? Have good or bad things to say, in terms of reliability, performance, features?
My main reason for asking is this: I have a mac, I use Time Machine, and I have VM's inside. Time Machine, while great in general, has the limitation of being unable to intelligently identify changed bits inside a VM file. So you have to exclude the VM from Time Machine, and you have to run backup software inside the VM.
I would greatly prefer, if it's reliable, to let the VM reside on ZFS and use zfs send to backup my guest VM's.
I am not looking to replace HFS+ as the primary filesystem of the mac; although that would be cool, there's often a reliability benefit to staying on the supported, beaten path, standard configuration. But if ZFS can be used to hold the guest VM storage reliably, I would benefit from that.
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