Raid vs directly attached ssds


#1

Hi,

We are migrating to a new datacenter that only support servers with RAID attached to it. Thus, i am comparing old server certification testing with new. Old server had SSD disk directly attached to motherboard. Also note that both servers use 800GB Intel S3700 Series SSDs.

JBOD configuration on New Server: /opt/MegaRAID/storcli/storcli64 -LDGetProp -Cache -Lall -aAll Adapter 0-VD 0(target id: 0): Cache Policy:WriteBack, ReadAhead, Direct, No Write Cache if bad BBU Adapter 0-VD 1(target id: 1): Cache Policy:WriteBack, ReadAdaptive, Direct, No Write Cache if bad BBU Adapter 0-VD 2(target id: 2): Cache Policy:WriteBack, ReadAdaptive, Direct, No Write Cache if bad BBU Adapter 0-VD 3(target id: 3): Cache Policy:WriteBack, ReadAdaptive, Direct, No Write Cache if bad BBU Adapter 0-VD 4(target id: 4): Cache Policy:WriteBack, ReadAdaptive, Direct, No Write Cache if bad BBU

I noticed that New server wth JBOD configuration is performing slowe than the first (although is does pass the certification tests criteria).

Is this normal, or should there be something wrong in the new server setup?

New server cert results for 1 disk on load 6X: ./latency_calc/act_latency.py -l sdb_6x_output.txt data is act version 3.0 trans device %>(ms) %>(ms) slice 1 2 4 8 16 32 64 1 2 4 8 16 32 64


1     8.90   7.29   6.48   5.22   1.16   0.02   0.00     7.93   4.72   3.00   1.82   0.11   0.00   0.00
2     8.86   7.25   6.44   5.17   1.10   0.01   0.00     7.90   4.69   2.97   1.80   0.11   0.00   0.00
3     8.77   7.19   6.39   5.12   1.08   0.01   0.00     7.81   4.62   2.94   1.79   0.11   0.00   0.00
4     8.77   7.20   6.39   5.13   1.08   0.01   0.00     7.81   4.63   2.95   1.80   0.11   0.00   0.00
5     8.89   7.27   6.45   5.18   1.12   0.01   0.00     7.92   4.70   2.98   1.82   0.10   0.00   0.00
6     8.91   7.29   6.47   5.21   1.13   0.01   0.00     7.94   4.73   2.99   1.81   0.10   0.00   0.00
7     8.94   7.31   6.48   5.22   1.14   0.01   0.00     7.98   4.74   3.00   1.82   0.10   0.00   0.00
8     8.89   7.27   6.46   5.19   1.12   0.01   0.00     7.92   4.71   2.98   1.81   0.11   0.00   0.00
9     8.90   7.27   6.46   5.20   1.13   0.02   0.00     7.93   4.70   2.98   1.80   0.11   0.00   0.00

10 8.87 7.26 6.45 5.18 1.11 0.01 0.00 7.91 4.69 2.98 1.81 0.10 0.00 0.00 11 8.89 7.26 6.45 5.19 1.13 0.01 0.00 7.93 4.69 2.98 1.81 0.11 0.00 0.00 12 8.88 7.27 6.46 5.19 1.12 0.01 0.00 7.92 4.71 2.98 1.81 0.11 0.00 0.00 13 8.91 7.29 6.47 5.20 1.13 0.02 0.00 7.95 4.72 2.98 1.81 0.11 0.00 0.00 14 8.89 7.28 6.46 5.20 1.14 0.02 0.00 7.92 4.70 2.98 1.81 0.11 0.00 0.00 15 8.91 7.28 6.47 5.20 1.13 0.02 0.00 7.95 4.71 2.98 1.81 0.11 0.00 0.00 16 8.88 7.27 6.46 5.20 1.13 0.02 0.00 7.92 4.69 2.98 1.81 0.11 0.00 0.00 17 8.92 7.29 6.47 5.20 1.13 0.02 0.00 7.97 4.73 2.99 1.81 0.11 0.00 0.00 18 8.89 7.28 6.46 5.19 1.12 0.01 0.00 7.94 4.72 2.99 1.81 0.10 0.00 0.00 19 8.92 7.29 6.47 5.20 1.11 0.01 0.00 7.96 4.72 2.99 1.81 0.10 0.00 0.00 20 8.88 7.27 6.45 5.18 1.10 0.01 0.00 7.93 4.71 2.98 1.81 0.10 0.00 0.00 21 8.92 7.29 6.47 5.20 1.12 0.02 0.00 7.96 4.73 2.99 1.81 0.10 0.00 0.00 22 8.89 7.28 6.46 5.19 1.13 0.01 0.00 7.93 4.71 2.98 1.81 0.11 0.00 0.00 23 8.92 7.29 6.47 5.20 1.12 0.01 0.00 7.96 4.73 3.00 1.81 0.10 0.00 0.00 24 8.90 7.28 6.46 5.20 1.12 0.02 0.00 7.93 4.72 2.98 1.81 0.11 0.00 0.00


avg 8.89 7.27 6.46 5.19 1.12 0.01 0.00 7.93 4.70 2.98 1.81 0.11 0.00 0.00 max 8.94 7.31 6.48 5.22 1.16 0.02 0.00 7.98 4.74 3.00 1.82 0.11 0.00 0.00

Old server cert results for 1 disk on load 6X:

/latency_calc/act_latency.py -l Server3_actconfig_6x_1d_sdc_last.txt data is act version 3.0 trans device %>(ms) %>(ms) slice 1 2 4 8 16 32 64 1 2 4 8 16 32 64


1     2.84   0.55   0.09   0.05   0.00   0.00   0.00     2.81   0.51   0.05   0.02   0.00   0.00   0.00
2     2.96   0.60   0.09   0.06   0.00   0.00   0.00     2.92   0.55   0.05   0.03   0.00   0.00   0.00
3     2.93   0.59   0.09   0.05   0.01   0.00   0.00     2.90   0.55   0.04   0.02   0.00   0.00   0.00
4     7.45   1.66   0.28   0.18   0.02   0.00   0.00     7.37   1.56   0.14   0.07   0.01   0.00   0.00
5     7.05   1.55   0.26   0.17   0.02   0.00   0.00     6.97   1.44   0.13   0.07   0.01   0.00   0.00
6     6.31   1.39   0.23   0.15   0.02   0.00   0.00     6.23   1.29   0.11   0.06   0.01   0.00   0.00
7     5.82   1.28   0.20   0.13   0.02   0.00   0.00     5.75   1.19   0.10   0.05   0.01   0.00   0.00
8     5.39   1.18   0.18   0.12   0.02   0.00   0.00     5.32   1.09   0.08   0.05   0.01   0.00   0.00
9     5.45   1.20   0.18   0.12   0.02   0.00   0.00     5.39   1.11   0.09   0.05   0.01   0.00   0.00

10 5.87 1.29 0.21 0.14 0.02 0.00 0.00 5.81 1.19 0.10 0.05 0.01 0.00 0.00 11 6.05 1.33 0.21 0.14 0.02 0.00 0.00 5.97 1.23 0.10 0.06 0.01 0.00 0.00 12 5.91 1.30 0.21 0.14 0.02 0.00 0.00 5.84 1.20 0.10 0.06 0.01 0.00 0.00 13 5.78 1.27 0.20 0.13 0.02 0.00 0.00 5.72 1.18 0.09 0.05 0.01 0.00 0.00 14 5.77 1.27 0.20 0.13 0.02 0.00 0.00 5.70 1.18 0.10 0.05 0.01 0.00 0.00 15 5.77 1.27 0.20 0.13 0.02 0.00 0.00 5.70 1.17 0.09 0.05 0.01 0.00 0.00 16 5.81 1.28 0.20 0.14 0.02 0.00 0.00 5.74 1.18 0.10 0.05 0.01 0.00 0.00 17 5.85 1.29 0.20 0.13 0.02 0.00 0.00 5.78 1.19 0.10 0.05 0.01 0.00 0.00 18 5.83 1.28 0.20 0.13 0.02 0.00 0.00 5.76 1.18 0.09 0.05 0.01 0.00 0.00 19 5.81 1.28 0.20 0.13 0.02 0.00 0.00 5.74 1.18 0.10 0.05 0.01 0.00 0.00 20 5.79 1.28 0.20 0.13 0.02 0.00 0.00 5.72 1.18 0.10 0.05 0.01 0.00 0.00 21 5.81 1.28 0.20 0.13 0.02 0.00 0.00 5.74 1.19 0.10 0.05 0.01 0.00 0.00 22 5.80 1.27 0.20 0.13 0.02 0.00 0.00 5.73 1.17 0.09 0.05 0.01 0.00 0.00 23 5.80 1.27 0.20 0.13 0.02 0.00 0.00 5.73 1.18 0.10 0.05 0.01 0.00 0.00 24 5.77 1.27 0.20 0.13 0.02 0.00 0.00 5.70 1.17 0.09 0.05 0.01 0.00 0.00


avg 5.57 1.22 0.19 0.13 0.02 0.00 0.00 5.50 1.13 0.09 0.05 0.01 0.00 0.00 max 7.45 1.66 0.28 0.18 0.02 0.00 0.00 7.37 1.56 0.14 0.07 0.01 0.00 0.00


Virtualization: VD vs Non-RAID mode for SSD
#2

https://www.aerospike.com/docs/operations/plan/ssd/ssd_setup.html has a section talking about usage of raid controllers. The data center you are refering to is from a french provider (OVH), right? I am also very interested in their offerings, specifically for AS nodes. If so, you might be very interested in this resource: https://www.aerospike.com/docs/operations/plan/ssd/lsi_megacli.html OVH uses these raid-chips.

It would be interesting to hear, what kind of op/s you got from such a setup.