Jump to content

MTTF Calculations in "A Case for RAID"

e(ho0n3
in Computer Science

Featured Replies

Hi everyone,

 

I'm reading the paper "A Case for RAID" and I'm having difficulty understanding some of the calculations made. Example:

 

Since we assume that disk failures occur at a uniform rate, this average number of second failures during the repair time for the X first failures is

 

[math]\frac{X*\mbox{MTTR}}{\mbox{MTTF of remaining disks in the group}}[/math]

 

So as X gets larger the above gets larger. This makes sense because it will take more time to repair more disks so the average number of second failures will grow. However, I'm not exactly sure how the formula is derived. Can anyone shed some light on this?

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications
Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.