a review of OpenZFS on OS X migration from ZEVO, part iii

Issues specific to non-OpenZFS pools (i.e., ZEVO & MacZFS).

a review of OpenZFS on OS X migration from ZEVO, part iii

Postby mjt5282 » Fri Mar 28, 2014 3:47 am

i uninstalled ZEVO and installed OpenZFS on OS X and here are my observations:

1) I didn't copy my data, I exported the ZFS pool, uninstalled the ZEVO software, rebooted, and installed the OpenZFS on OS X DMG file. You may recall I installed one of the beta versions and gave my impressions on IRC a while back. I am running 10.8.5 on a 2008 Mac Pro with 32Gb of RAM. The ZFS pool is a 8x3Tb raidz2. It actually imported fine and reports no errors in normal day to day running.

2) iTunes library of mp3 files is acting very funny. Most of the older mp3s can't be found by iTunes. Its as if it has 'reset' the location of its mp3 library because it was missing during a reboot or something. As I have nearly 30,000 mp3's it is a bit of a pain. I am continuing to look at this problem. This is the biggest issue for me, for i am a flac person, but make a mp3 copy for my car/out of the house roaming.

3) ZFS scrubbing runs at a fraction (5%) of the speed of the ZEVO scrub. It scrubs too slow to actually finish my ~13Tb pool. ZEVO will scrub in about 30 hours, OpenZFS on OS X was estimating 225 hours. I let it run for about 8 hours and the speed didn't improve. I cancelled the scrub.

4) I have a 2nd identical 8x3Tb raidz2 backup pool (called backup, naturally) that I connect once a week and rsync the data from the primary pool to the backup pool. Things went haywire with the Finder while the backup pool was imported (with the same filesystems names but different pool names). It was almost like the finder was adding mounts and deleting mounts in parallel. Very odd. ZEVO doesn't do this. My finder options only have the 'primary' mount point displayed with the Finder.

5) My L2ARC SSD failed to be used - the cache wasn't accessed and didn't grow like it does with ZEVO. Now perhaps as a home user I don't really need a SSD L2ARC cache but it was nice to have and did speed up ZEVO's disk accesses to my large media collections (flac and MKV).

6) The most important point is , although L2ARC is currently not working for me and I can't do scrubs, it hasn't blue screened on my and is very fast and stable in day-to-day operations. Dare I say, it is a keeper. Congrats to lundman and ilovezfs and the other members of the OpenZFS on OS X team for a very worthwhile release!
mjt5282
 
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Re: a review of openZFS migration from Zevo, part iii

Postby modahamburger » Fri Apr 04, 2014 6:56 am

Hi,

I also migrated from ZEVO to OpenZFS. I tried the DMG install and from source (bit more geeky=more fun).

I noticed that the Kernel process (within both ZEVO and OpenZFS "allocated/use" the RAM) is occupying much less RAM.
I have 4 x 1TB in RAID-z and total of 6GB RAM installed.
Before with Zevo Kernel used between 2.5-3GB RAM.
Now it uses just under 1GB RAM?
Maybe thats the issue why it is much slower? Scrubbing and writing/moving big files is much, much slower than ZEVO.

Any suggestion? Can I set somewhere OpenZFS to use as much RAM as possible, but leave e.b. 1GB free?
I saw that this is possible on other ZFS systems, but where do I set this in the OSX implementation?

And by the way, thanks for bringing OpenZFS to OSX!

Cheers!
modahamburger
 
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Re: a review of openZFS migration from Zevo, part iii

Postby Brendon » Fri Apr 04, 2014 1:56 pm

Hi Modahamburger,

If you are able to compile the openzfs code for yourself, there is a branch in the spl called "bmalloc". It contains what will potentially be our replacement for the kernel memory allocator. It allows a lot more of your system ram to be utilised without fear of panicking the kernel. With this branch you can safely set arc to use 25%-40% of your machines RAM (actual memory usage will be quite a bit higher than that due to overheads in the allocator itself).

We are of course interested in any feedback regarding the performance of that branch.

The usual disclaimers apply - it is relatively new, the code is still being finessed, and it does not have the widespread use of the master branch. I myself use it on all of my machines and have done so for a while.

Cheers
Brendon


modahamburger wrote:Hi,

I also migrated from ZEVO to OpenZFS. I tried the DMG install and from source (bit more geeky=more fun).

I noticed that the Kernel process (within both ZEVO and OpenZFS "allocated/use" the RAM) is occupying much less RAM.
I have 4 x 1TB in RAID-z and total of 6GB RAM installed.
Before with Zevo Kernel used between 2.5-3GB RAM.
Now it uses just under 1GB RAM?
Maybe thats the issue why it is much slower? Scrubbing and writing/moving big files is much, much slower than ZEVO.

Any suggestion? Can I set somewhere OpenZFS to use as much RAM as possible, but leave e.b. 1GB free?
I saw that this is possible on other ZFS systems, but where do I set this in the OSX implementation?

And by the way, thanks for bringing OpenZFS to OSX!

Cheers!
Brendon
 
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Re: a review of openZFS migration from Zevo, part iii

Postby modahamburger » Sat Apr 05, 2014 3:55 am

Thanks for your reply.
Hope I have done it correctly:
1. Cloned the source as in the wiki.
2. built with zfsadm
3. in spl directory "git checkout bmalloc"
4. Checked with git status, am on bmalloc
5. make as per wiki (cd ~/Developer/zfs
sudo make install
cd ~/Developer/spl
sudo make install)
6. verify kexts are loaded

Did I install now the bmalloc branch?

How do I set the amount of RAM allocated to the ARC?

Thanks so much for your help.
modahamburger
 
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Re: a review of openZFS migration from Zevo, part iii

Postby modahamburger » Sun Apr 06, 2014 7:53 am

I tired increasing ARC with
"sudo sysctl -w zfs.arc_max=2684354560"

Tried even same number for min…… no change in RAM occupation.

Suggestions please????
modahamburger
 
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Re: a review of openZFS migration from Zevo, part iii

Postby Brendon » Mon Apr 07, 2014 6:37 pm

modahamburger wrote:I tired increasing ARC with
"sudo sysctl -w zfs.arc_max=2684354560"

Tried even same number for min…… no change in RAM occupation.

Suggestions please????


Hi Modahamburger,

bmalloc and an increase in the default arc size from 6% of physical memory to 25% of physical memory have now been merged into master.

You can either build and deploy that, or wait for the next stable release along with its installer.

Cheers
Brendon
Brendon
 
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Re: a review of OpenZFS on OS X migration from ZEVO, part ii

Postby modahamburger » Thu Apr 10, 2014 12:31 pm

Thanks.
Got a small problem with shutting down. Need to take a screenshot, but after all processes in verbose mode have been killed, it says continuing..... And noting happens.
Anyhow, will post a screenshot another.

Thanks again!
modahamburger
 
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Re: a review of OpenZFS on OS X migration from ZEVO, part ii

Postby ilovezfs » Fri Apr 11, 2014 12:04 am

It is safe to hard power off at that point. This is a known issue that happens from time to time.
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Re: a review of OpenZFS on OS X migration from ZEVO, part ii

Postby haer22 » Thu May 08, 2014 8:12 am

Well, that happens to me almost all the time. So I cannot do a reboot from a remote location as a finger needs to push a button.

ilovezfs wrote:It is safe to hard power off at that point. This is a known issue that happens from time to time.
haer22
 
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