zfs discuss - Feb 2013 - maczfs / ZEVO

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...
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On Fri, Feb 15, 2013 at 10:08 AM, Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris) <
opensolarisisdeadlongliveopensolaris at 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...****
>
>
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
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Edward Ned Harvey (opensolarisisdeadlongliveopensolaris)
writes:
> 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: vab at bb-c.de
Handelsregister: Amtsgericht Bonn, HRB 10513              Schuhgr??e: 46
Gesch?ftsf?hrer: Rainer J.H. Brandt und Volker A. Brandt

"When logic and proportion have fallen sloppy dead"

On Feb 15, 2013, at 11:08 AM, Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris) <opensolarisisdeadlongliveopensolaris
at nedharvey.com<mailto:opensolarisisdeadlongliveopensolaris at
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
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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

On 15 f?vr. 2013, at 17:08, "Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris)"
<opensolarisisdeadlongliveopensolaris at 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.
> 
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> From: Tim Cook [mailto:tim at cook.ms]
> 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?

On 17 f?vr. 2013, at 15:15, "Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris)"
<opensolarisisdeadlongliveopensolaris at nedharvey.com> wrote:
>> From: Tim Cook [mailto:tim at cook.ms]
>> 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

> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss-
> bounces at opensolaris.org] On Behalf Of Edward Ned Harvey
> 
> 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.

On Feb 17, 2013, at 9:15 AM, Edward Ned Harvey
(opensolarisisdeadlongliveopensolaris) wrote:
>> From: Tim Cook [mailto:tim at cook.ms]
>> 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