ZFS Performance Testing: Dell PowerEdge 2900

***Update***
This started a simple post to share a few results from various levels of zfs/array testing. Be sure to check back from time to time as I add additional configuration results.

***Begin Original Text***
I have been playing around with ZFS on various operating systems lately and have been trying to compare performance. I figured that sharing some of my results would give others something to compare with. Plus, I am on borrowed time with this unit, it is big, loud, and taking up free space and spare time in the home office.

Test rig:

• Dell PowerEdge 2900
• Xeon Dual Core 3.0GHz (HT Enabled-OS showing 4 cores)
• 14GB RAM
• PERC5 – Total of 7 logical drives with read ahead and write back enabled.
• 2x146GB SAS 15K RPM – Hardware RAID1 for OS
• 6x1TB SATAII 7200 RPM – Six (6) SATAII 7200 RPM Disks for testing. (Controller does not support JBOD mode)
• FreeNAS 0.7.2 Sabanda (revision 5543)-ZFS v13

GNU dd:
Tests performed from the CLI using good ole’ GNU dd. The following command was used to first write, and then read back:

dd if=/dev/zero of=foo bs=2M count=10000 ; dd if=foo of=/dev/null bs=2M

Results: Each disk configured as a separate RAID0 array on controller.
Results are listed as configuration, write, then read.

• ZFS raidz1 pool utilizing six (6) SATA disks
  • 133 MB/s
  • 311 MB/s

• ZFS raidz1 pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 414 MB/s
  • 359 MB/s

• ZFS raidz2 pool utilizing six (6) SATA disks
  • 180 MB/s
  • 286 MB/s

• ZFS raidz2 pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 414 MB/s
  • 361 MB/s

• ZFS stripe pool utilizing six (6) SATA disks
  • 190 MB/s
  • 263 MB/s

• ZFS stripe pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 429 MB/s
  • 381 MB/s

Results: Each disk configured as a member of a single RAID0 array.
Results are listed as configuration, write, then read.

• ZFS stripe pool utilizing six (6) SATA disks
  • 353.4 MB/s
  • 473.0 MB/s

• ZFS stripe pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 420.8 MB/s
  • 340.9 MB/s

Results: Each disk configured as a member of a single RAID5 array.
Results are listed as configuration, write, then read.

• ZFS stripe pool utilizing six (6) SATA disks
  • 322.0 MB/s
  • 325.9 MB/s

• ZFS stripe pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 438.8x MB/s
  • 371.8 MB/s

Results: Each disk configured as a member of a single RAID10 array.
Results are listed as configuration, write, then read.

• ZFS stripe pool utilizing six (6) SATA disks
  • 251.2 MB/s
  • 304.3 MB/s

• ZFS stripe pool utilizing six (6) SATA disks with dataset compression set to “On”
  • 430.7 MB/s
  • 360.9 MB/s

Notes, Thoughts & Mentionables:
It is worth noting that the results of the datasets with compression on can be a bit misleading. This is due to the source we are using with dd; /dev/zero. Feeding a string of zeroes into a compression algorithm is probably the best case scenario when it comes to compression. In real world conditions, data being read or written that is compressible would experience an increase in performance, while non-compressible data would likely suffer a penalty.

I am hoping to conduct the same tests on the exact hardware in the near future. I will be switching the six (6) SATA disks over to varying hardware RAID levels and comparing them again.

***Update***
In a follow-up post to this one, I concluded that compression read and write performance on this particular test rig was being limited by the CPU. I am hoping to swap out the current Intel Xeon 3.0GHz dual core for a quad core for additional comparison.

–himuraken