09/19/2017 aerialsurveybase

RAID-5: RAID comparison 8x Toshiba X300 array (Part 5)

Raid Level Comparison

Toshiba_X300__SATA_DriveDrives used for test:

Toshiba X300 Extreme Performance HDD,  6TB (HDW160EZSTA)
(link)

Technical specs:
3,5“ mechanical HDD • 7.200rpm • Cache: 128MB • power consumption: 11.3W, 6W (idle) • Perpendicular Magnetic Recording (PMR) • sectors: 4KB (Emulation 512e), integrated shock sensor, weight: 720g, interface: SATA 6 Gbit/s

in Part 5 we talked about The Myth of Redundancy in Data Storage and learned something about reliability and redundancy. But what will be happen, when using a modern, state-of-the-art mass storages, such a high performance Toshiba hard drive.

Measured Single drive performance:

Toshiba_X300__SATA_Drive Performance Test (MB/sec) Read aver. Read max. Write aver. Write max.
HD Tune Pro sequential: 170.4 224.4 166.9 217.5
A.S. SSD Benchmark: 204.8 199.7
ATTO Disk Benchmark: 214.5 211.3
Crystal Disk Mark: 216 214
access time: 10-14 ms

8x6TB_Toshiba_X300

8x 6TB Toshiba X300 High Performance Drives

Calculated RAID Level performances:

(Read/write ratio 50/50%, using 8 Toshiba X300 drives)

RAID 0 RAID 5 RAID 6 RAID 10
Single RAID group performance  (MB/s): 1.680 672 480 1120
Total usable storage capacity (TB): 48 42 36 24
Cost per TB usable: 33,33 38,10 44,44 66,67
Total costs (USD): 1.600

 

RAID Reliability Calculation: 

(using 8x Toshiba X300 drives):

RAID 5 RAID 6 RAID 10
Drive Annual Failure Rate (%) 6,05
Combined system MTTDLTOTAL: 2,1 693 5,2
Probability of data loss over time:
1    year 0,37 0,001 0,17
1.5  years 0,69 0,003 0,37
3     years 0,91 0,007 0,60
calculated by using RAID type, conservative real world MTBF, LSE rate 1014, replacing failed drive within 48 h, rebuild rate 80% for Toshiba X300 6TB

Conclusion:

As we learned, RAID 0 provide us, comparing to other levels, with real light speed processing.

continue with Part 6, where we figure out, why RAID is not a backup.

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