Thanks for all the replies guys =D

Sorry for lack of information. I'm running a Hackintosh with a 256 GB
SSD and I sometimes run Windows 8.1 in a virtual machine via VmWare
Fusion. The virtual image file is also located on the SSD. The only
files I have on my zpool are data files. I don't run an OS or VM image
from it. I have 12 GBs of RAM and a four core i5 processor. On the VM,
I dedicate 6 GBs of RAM and 2 cores to it. It should be noted that I
experience the slow down even when vmware is off it's just the drives
act the slowest when the VM is running.

As for how I created the zpool, I followed the Getting Started guide with

zpool create murr raidz disk3s2 disk1s2 disk2s2 disk4s2

Please help... I really hope I don't have to recreate it, but it's
looking that way.

Would it be better if I bought a RAID card and use Mac OS Journaled?
Cost is an issue... the other issue is these are regular desktop 7200
RPM drives.. not NAS drives.



On Mon, May 19, 2014 at 7:43 AM, Jason Belec <> wrote:
> Dave has posted some good info. Reminds me why I prefer Virtualbox. ;) We do 
> seem to need more detail though to really help the original OP.
> Jason
> Sent from my iPhone 5S
>> On May 19, 2014, at 4:00 AM, Dave Cottlehuber <> wrote:
>> From: James Hoyt
>> Reply: 
>> Date: 19. Mai 2014 at 02:27:36
>> To: 
>> Subject: [zfs-macos] RAIDZ1 running slow =(
>>> So I setup a MacZFS RaidZ rather easily and was happy with myself. I had 
>>> four 3 TB internal SATA drives in a zpool giving me around 9 TB of space.
>>> jamess-imac:~ sangie$ zpool status murr
>>> pool: murr
>>> state: ONLINE
>>> scrub: none requested
>>> config:
>>> murr ONLINE 0 0 0
>>> raidz1 ONLINE 0 0 0
>>> disk3s2 ONLINE 0 0 0
>>> disk1s2 ONLINE 0 0 0
>>> disk2s2 ONLINE 0 0 0
>>> disk4s2 ONLINE 0 0 0
>>> errors: No known data errors
>>> So I Filled it up with about 5 GBs of data, mainly images and FLAC/music 
>>> files and everything just drags on it. It takes a long time for files to be 
>>> listed in finder and when I try to save an image from Firefox, it will just 
>>> grind and grind while I try to navigate to a folder. I have vmware Fusion 
>>> setup on my SSD (my main Mac drive) and doing anything on my zpool from 
>>> Windows (like using MediaMonkey to organize FLAC files on it) uses up 100% 
>>> of the CPU, freezing up my computer until the moves are done, even when 
>>> moving around 30 files.
>> It’s not clear from this what your actual physical / virtual setup is. Are 
>> you booting to OSX, and running Windows in a VM? Is the entire VM then 
>> living on the raidz pool?
>>> Is my zpool okay? What's going on? Is this type of slowness normal or do I 
>>> have a bad drive? How will MacZFS report to me if a drive in the array goes 
>>> bad? I installed SMARTReporter Lite and it shows all drives as green. If I 
>>> have some drives on SATA II and others on SATA III would that affect 
>>> anything?
>>> If you want me to run any tests on it, I will do so gladly. Just let me 
>>> know.
>>> Thanks!
>> I’ve seen precisely this sort of behaviour with vmware fusion when:
>> 1. my SSD was getting worn down (really, I trashed it in 1 year, it was the 
>> default apple one coming with early 2011 MBP)
>> 2. the host OS & VM doesn’t have sufficient memory to run correctly without 
>> swapping
>> 3. the additional memory within the VM is pulled from a disk swap file, 
>> which is by default in the same disk location as the VM itself
>> Anything less than 8GB of RAM is likely to be tight, VMs will of course make 
>> this more complicated. Some notes on 
>> may help.
>> I found that my SSDs were being worn out with constant running of VMs; I use 
>> them heavily in my work. The solution I found was to get max RAM in my 
>> laptop + imac (16 vs 32 respectively), make a zfs based ramdisk with lz4 
>> compression, and copy the entire VM into the ramdisk before running it. The 
>> copy phase only takes a few seconds from SSD, and it gives me a very nice 
>> way to “roll back” to the previous image when required. I can comfortably 
>> run Windows in a 20GiB ramdisk that fits inside a 10GiB zpool with 
>> compression, even on the 16GiB laptop, and allocating 2GiB of ram for the VM 
>> itself (10 + 2 for virtualisation & leave 4 for all of OSX stuff).
>> Here’s the zsh functions I use for this.
>> # create a 1GiB ramdisk
>> ramdisk-1g () {
>>    ramdisk-create 2097152
>> }
>> # the generic function for the specific one above
>> ramdisk-create () {
>>    diskutil eject /Volumes/ramdisk > /dev/null 2>&1
>>    diskutil erasevolume HFS+ 'ramdisk' `hdiutil attach -nomount ram://$1`
>>    cd /ramdisk
>> }
>> # make a zpool backed ramdisk instead of the HFS+ ones above. Main advantage 
>> is compression. I get at least 2x more “disk” for RAM with this approach.
>> zdisk () {
>>    sudo zpool create -O compression=lz4 -fm /zram zram `hdiutil attach 
>> -nomount ram://20971520`
>>    sudo chown -R $USER /zram
>>    cd /zram
>> }
>> # self explanatory
>> zdisk-destroy () {
>>    sudo zpool export -f zram
>> }
>> —
>> Dave Cottlehuber
>> Sent from my Couch
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