RAID Reliability Calculator

This RAID calculator computes storage system reliability using well-known MTTDL methodology.
Supported RAID levels are RAID 1, RAID 5, RAID 10 (1+0), and RAID 6.

Mission time (year):
RAID Type:
Number of drives in a RAID group:	Equals 2 for RAID1. Usually in the range between 3 and 12 for other RAIDs. Must be an even number for RAID10.
Number of RAID groups:
Drive Capacity (GB):
Drive Throughput (MB/s):	Usually in the range between 40 MB/s (SATA/7200) and 100 MB/s (SAS/15K).
Drive MTBF (hour): or	To use this parameter clear the field below.
Annual failure rate (%):	This value overrides the selection from the Drive MTBF field above. Clear this field to use the Drive MTBF parameter.
Latent Sector Error (LSE) rate:	Usually in the range between 1.0e^-17 and 1.0e^-13. The lower value is better.
Time to replace failed drive (hour):	0 if hot spare is available.
Rebuild rate (%): or	To use this parameter clear the field below.
Time to rebuild (hour):	This value overrides the selection from the Rebuild rate field above. Clear this field to use the Rebuild rate parameter.

Results:

Total Usable Storage Capacity (GB)	36000
Number of RAID Groups	10
Number of drives per RAID Group	8
Total Number of Drives:	80
Drive Capacity (GB)	600
RAID Type:	R6
Drive Throughput (MB/s)	100
Drive MTBF (hour)	2000000
Drive Annual Failure Rate (%)	0.438
Drive MTTR (hour)	3.33333333333333
System MTTDL_DF (due to multiple drive failures)	428571428571428 hours 48923679060.6653 years
Probability of read error during rebuild	0.0002879585319810
System MTTDL_LSE (due to read error during rebuild)	7441547670476.85 hours 849491743.205119 years
Combined system MTTDL_TOTAL	7314540827218.92 hours 834993245.116315 years
Probability of data loss over time
1 year	0.0000000011976145
5 years	0.0000000059880724
10 years	0.0000000119761447