OpenZFS on OS X

Hello.
I am new here and tried ZFS the first time. My machine is a MacPro with an 2,8 Quad and the latest "El Capitan". I have created all kind of zfs: On a single disk, mirrored an 2 disks, raidz1 with 3 disk. But they are all really slow:

pool alloc free read write read write
---------- ----- ----- ----- ----- ----- -----
einzel 1,66G 296G 2 6 3,23K 147K
disk2 1,66G 296G 2 6 3,23K 147K
---------- ----- ----- ----- ----- ----- -----
meinzfs 6,18G 458G 2 0 2,48K 417
mirror 6,18G 458G 2 0 2,48K 417
disk1 - - 1 0 1,42K 443
disk3 - - 1 0 1,44K 443
---------- ----- ----- ----- ----- ----- -----

The disks are OK. with hfs+ they work quit nice and fast.

Its a fresh "El Capitan" (with server) and I don´t see the problem. I don´t find threads to this. The only one I found say to turn off throttling. But that doesn´t help.

Have anybody a suggestion for me.
Thanks
Al

You need to provide a lot more info, hardware configuration, zpool create commands, how you're load testing, etc

Brendon

Ok: here it is
Like I have written its a MacPro 2008 2,8 GHz Quad with 5GB
The systemdisk is a SSD with 250GB hfs+
I have further 3 disks inside: 500GB hitatchi, 500GB Samsung, 320GB WD (older ones, but tested)
I created with:
zpool create meinzfs raidz1 /dev/disk1 /dev/disk2 /dev/disk3
or
zpool create meinzfs mirror /dev/disk1 /dev/disk3
and with
zpool create einzel disk2

Then I give everybody read and write permissions (in the Finder infowindow)

The result is quit the same on all configurations: very slow: To copy a folder with 3GB from the system SSD takes more than 10 minutes
What other kind of infos you need?

Hi @alobi

Ok, I have a similar machine, it boots off an SSD, and has a raidz made up of three partitions spread across 3 old hdds (750G, 1.5T, 2.0T). The drives are old and have been ejected from my main array in some cases due to possible hardware failures. Ashift and compression help performance significantly, especially with 4k sector disks. I doubt your disks are 4k due to their size (proxy for age). These are all internal SATA connected. If you are using USB the results will be very different.

First of all to create a zfs dataset on a mac:

Code: Select all

zpool create -o ashift=12 -O casesensitivity=insensitive -O normalization=formD -O compression=lz4 tank raidz disk1s1 disk2s2 disk3s2


Copying a large file ~3G from the ssd to the raidz:

Code: Select all

fatmac:~ zadmin$ sudo time cp apps.tar /Volumes/tank/brendon/
       16.75 real         0.00 user         4.69 sys


and disk performance:

Code: Select all

zpool iostat 1
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        1.39G  2.03T      0  1.16K      0   146M
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        1.39G  2.03T      0  1.43K      0   182M
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        1.39G  2.03T      0  1.40K      0   164M
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        2.11G  2.03T      0  1.37K      0   175M


Now, copying /Applications to the raidz (many small files). This is going to be much slower. I did this because you don't say what size files you are copying. /Applications is full of small files typically. If I were to copy large amounts of media files, I would get performance more like the first case.

Code: Select all

zpool iostat 1

big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.88G  2.02T    173      0   276K   127K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.97G  2.02T     18    647  51.8K  64.1M
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.97G  2.02T      2      0  2.49K   128K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.97G  2.02T      0      2      0   383K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.97G  2.02T      0      0      0   128K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        7.97G  2.02T      0      1  3.98K   255K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        8.07G  2.02T      2    803  12.0K  61.4M
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        8.07G  2.02T      0      1      0  71.9K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        8.07G  2.02T      0      0      0  36.0K
----------  -----  -----  -----  -----  -----  -----
big          206G   954G      0      0      0      0
small       16.0M   696G      0      0      0      0
tank        8.07G  2.02T     33      2  25.4K   107K


You can see a pattern forming there. Its probably averaging 20MB a second. ZFS is definitely slower that HFS in almost all respects. It is designed for robustness, not performance. It is the nature of the beast.

Don't use the finder to play with read and write permissions, use the command line.

You can do similar tests on your machine, and report back.

Brendon

Hi Brendon

Thanks for your detailed answer. Simultaneous I had make tests with different folders. The one I discribe is a folder with apps. I have tried the "El Capitain" Installer and it goes much faster. Lets say in a normal speed.

I will try, what you have written and post the results.

thanks
Al

OK. I have play a little bit and created the raid with your commands. It doesn´t help very much, but I have learned a lot. I could speed up the raid with a part of the ssd as cache.
And I like your sentence "It is designed for robustness, not performance. It is the nature of the beast".
I think I have the wrong expectation. But I like zfs and will go one with it.

Thanks for your hinds.
Al