We are currently building a new NAS for our VMware ESXi servers, but we are getting very bad results from two new Crucial M500 (120GB) SSD's if we use them as SLOG devices (striped and mirrored).
Just to give you an idea what we are working with:
Build FreeNAS-9.2.1.3-RELEASE-x64 (dc0c46b)
Platform Intel Xeon CPU E3-1245 v3 @ 3.40GHz
Motherboard: SuperMicro MBD-X10SL7-F
Memory 32706MB (ECC)
HD: 6x WesternDigital WD2000FYYZ (2TB) in RAIDZ2 (so 7.1 TIB usable)
Controller: LSI 2308 (flashed to HBA mode) (all six HD's are connected to this controller)
We are doing some testing before we migrate to this new NAS, So we first started to do a baseline test using only the HD's without a separate SLOG device. We created a ZFS volume and shared this using an NFS to one of our ESXi servers. We installed a virtual Windows 7 x64 machine and did some benchmarking with HD Tune Pro 5.50 using the Random Access test.
Without an SLOG device
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 115 IOPS 8.643 ms 51.265 ms 0.056 MB/s
4 KB 110 IOPS 9.071 ms 57.329 ms 0.431 MB/s
64KB 98 IOPS 10.182 ms 87.282 ms 6.138 MB/s
1 MB 6 IOPS 156.015 ms 493.247 ms 6.410 MB/s
Random 11 IOPS 83.850 ms 397.923 ms 6.051 MB/s
Then we wanted to know if we could increase the performance using an two year old Intel 330 SSD (60GB):
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 2844 IOPS 0.351 ms 5.678 ms 1.389 MB/s
4 KB 2252 IOPS 0.443 ms 5.139 ms 8.798 MB/s
64KB 865 IOPS 1.168 ms 8.031 ms 53.476 MB/s
1 MB 95 IOPS 10.421 ms 185.222 ms 95.956 MB/s
Random 167 IOPS 5.966 ms 147.249 ms 85.03951 MB/s
It seemed we increased the performance by roughly tenfold, So then we started testing with two new Crucial M500 SSD's (120GB) which we wanted to run in mirror mode. we were expecting even better performance then the Intel 330 (60GB) but the results tell us a different story. The newest firmware for the Crucual M500 almost doubled the performance during our initial test but still... see below.
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 212 IOPS 4.710 ms 11.323 ms 0.104 MB/s
4 KB 213 IOPS 4.690 ms 8.654 ms 0.833 MB/s
64KB 183 IOPS 5.458 ms 8.965 ms 11.451 MB/s
1 MB 13 IOPS 74.334 ms 138.768 ms 13.453 MB/s
Random 24 IOPS 40.888 ms 300.490 ms 12.409 MB/s
We tried everything we could think of to increase the performance.
We are now thinking about moving on and buying a single Intel S3500 or S3700 SSD, or even the new Intel 730. Or getting a Seagate 600 Pro. But we can sleep a little better if we could find an explanation why these two Crucial M500 SSD's are performing so slow.
Just to give you an idea what we are working with:
Build FreeNAS-9.2.1.3-RELEASE-x64 (dc0c46b)
Platform Intel Xeon CPU E3-1245 v3 @ 3.40GHz
Motherboard: SuperMicro MBD-X10SL7-F
Memory 32706MB (ECC)
HD: 6x WesternDigital WD2000FYYZ (2TB) in RAIDZ2 (so 7.1 TIB usable)
Controller: LSI 2308 (flashed to HBA mode) (all six HD's are connected to this controller)
We are doing some testing before we migrate to this new NAS, So we first started to do a baseline test using only the HD's without a separate SLOG device. We created a ZFS volume and shared this using an NFS to one of our ESXi servers. We installed a virtual Windows 7 x64 machine and did some benchmarking with HD Tune Pro 5.50 using the Random Access test.
Without an SLOG device
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 115 IOPS 8.643 ms 51.265 ms 0.056 MB/s
4 KB 110 IOPS 9.071 ms 57.329 ms 0.431 MB/s
64KB 98 IOPS 10.182 ms 87.282 ms 6.138 MB/s
1 MB 6 IOPS 156.015 ms 493.247 ms 6.410 MB/s
Random 11 IOPS 83.850 ms 397.923 ms 6.051 MB/s
Then we wanted to know if we could increase the performance using an two year old Intel 330 SSD (60GB):
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 2844 IOPS 0.351 ms 5.678 ms 1.389 MB/s
4 KB 2252 IOPS 0.443 ms 5.139 ms 8.798 MB/s
64KB 865 IOPS 1.168 ms 8.031 ms 53.476 MB/s
1 MB 95 IOPS 10.421 ms 185.222 ms 95.956 MB/s
Random 167 IOPS 5.966 ms 147.249 ms 85.03951 MB/s
It seemed we increased the performance by roughly tenfold, So then we started testing with two new Crucial M500 SSD's (120GB) which we wanted to run in mirror mode. we were expecting even better performance then the Intel 330 (60GB) but the results tell us a different story. The newest firmware for the Crucual M500 almost doubled the performance during our initial test but still... see below.
Transfer size Operations / sec avg. access time max. access time avg. Speed
512 bytes 212 IOPS 4.710 ms 11.323 ms 0.104 MB/s
4 KB 213 IOPS 4.690 ms 8.654 ms 0.833 MB/s
64KB 183 IOPS 5.458 ms 8.965 ms 11.451 MB/s
1 MB 13 IOPS 74.334 ms 138.768 ms 13.453 MB/s
Random 24 IOPS 40.888 ms 300.490 ms 12.409 MB/s
We tried everything we could think of to increase the performance.
- Updated the firmware
- Changed AHCI mode to IDE
- Switched SATA controllers
- Using only a single Crucial M500 (tried both)
We are now thinking about moving on and buying a single Intel S3500 or S3700 SSD, or even the new Intel 730. Or getting a Seagate 600 Pro. But we can sleep a little better if we could find an explanation why these two Crucial M500 SSD's are performing so slow.