EXT4 vs XFS: large volumes with low-end RAID controller

Written by Gionatan Danti on . Posted in Linux & Unix

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Testbed and methods

The Dell R510 have the following hardware and software configuration:

  • 2x Intel Xeon E5620 with HT OFF (4 cores, 4 threads , 12 MB L3 cache) @ 2.4 GHz

  • 8x 4 GB DDR3 RAM (32 GB total RAM)

  • PERC H200 RAID Controller

  • 12x 2 TB 7.2K RPM SATA 3Gps disks

  • Red Hat Enterprise Linux 6.0 64 bit

 

The 12 disks were assigned to 2 RAID array:

  • a first, 2 disks RAID 1 array for OS installation

  • a second, 10 disks RAID 10 array for the benchmark runs

 

To run the benchmarks, I used the following softwares:

  • bonnie++-1.96-1.el6.rf.x86_64.rpm

  • sysbench-0.4.12-1.el6.x86_64.rpm

  • mysql-server-5.1.52-1.el6_0.1.x86_64.rpm

  • mysql-bench-5.1.52-1.el6_0.1.x86_64.rpm

  • postgresql-server-8.4.7-1.el6_0.1.x86_64.rpm

  • postgresql-test-8.4.7-1.el6_0.1.x86_64.rpm

 

Please note that the benchmarked filesystems were optimized for the physical array layout (in this case, 5 active data disks and 64 KB stripe size). Remember that, as stated before, the PERC H200 controller does not have any onboard cache, and it disable any disk-level cache it found on the attached disks. For this reason, write barriers were disabled.

I run each benchmark at least 3 times and then reported the mean value.

A note on the CPU load number: as this Dell R512 has 8 physical cores that can manage 8 hardware threads (HyperThreading was set to OFF), the maximum CPU load percentage, as reported by the Linux kernel, is 800%. So, if when you read something similar to “100% CPU load”, this mean that, on average, only one core (from the 12 available) was fully utilized.

UPDATE 05/06/2011: hardware description was updated to correctly describe the core/threads configuration. I originally wrote that the CPUs were two hexa-cores ones, while they really are two quad-cores processors.

UPDATE 05/10/2011: a reader ask to me explicitly specify the mkfs and mount parameters. For filesystems creation, I use the following commands:

  • EXT4: mkfs.ext4 /dev/sdb1 -E stride=16,stride-width=80
  • XFS: mkfs.xfs /dev/sdb1 -d su=64k,sw=5

Both filesystems were mounted with default parameters and the "nobarrier" option.

Comments   

 
#1 musculare 2014-04-13 09:08
Spot on with this write-up, I absolutely think this website needs far more attention.
I'll probably be back again to see more, thanks for the info!
 

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