-- Nov 4 In-Class Exercise Thread
Concrete parameters:
Setting the RTO to be 5 hours would enforce a type of hard disk that needs to be use.
Essentially, we need to make sure to use a hard drive less than a certain size to satisfy the RTO condition.
RTO objective = replacement process time = 5 hours = 5/24 days = 5/8760 years
The odds that a disk will fail during the replacement process is:
1 failure / (MTTF for 1 disk = 10 years) * 5/8760 years = 5/87600 years = 1/17520 years
If we have 5 disks (each with an MTTF being 10 years) then the MTTF for 5 disks is 10/5 = 2 years.
Therefore, the mean time to data loss is 2 * 17520 = 35,040 years.
(
Edited: 2020-11-04)
Concrete parameters:
Setting the RTO to be 5 hours would enforce a type of hard disk that needs to be use.
Essentially, we need to make sure to use a hard drive less than a certain size to satisfy the RTO condition.
RTO objective = replacement process time = 5 hours = 5/24 days = 5/8760 years
The odds that a disk will fail during the replacement process is:
1 failure / (MTTF for 1 disk = 10 years) * 5/8760 years = 5/87600 years = 1/17520 years
If we have 5 disks (each with an MTTF being 10 years) then the MTTF for 5 disks is 10/5 = 2 years.
Therefore, the mean time to data loss is 2 * 17520 = 35,040 years.