[CentOS] How to stagger fsck executions

Wed Apr 22 17:56:08 UTC 2015
Hugh E Cruickshank <hugh at forsoft.com>

From: Warren Young Sent: April 21, 2015 14:13
> On Apr 21, 2015, at 9:50 AM, Hugh E Cruickshank wrote:
> > 
> > From: Kay Diederichs Sent: April 21, 2015 03:43
> >> 
> >> instead of having 20 for all of them, set
> >> the first filesystem to 17, the second to 19, the third to 
> 23, and the
> >> fourth to 29.
> > 
> > Thanks but that is not much different then my second idea 
> and does not
> > fully avoid the problem.
> 
> You may be missing a key fact of how prime numbers work.

You are right and I stand corrected.

I have done some "what if" testing. Assuming 8 filesystems and weekly
reboots over a ten year period...

The random numbers would result in as many as 40 weeks per year where
2, 3 or 4 fscks would be run in the same week depending on the random
numbers selected.

Using the prime numbers 7, 11, 13, 17, 19, 23, 29 and 31 the is a
maximum of 7 incidents per year of 2 fscks per week and none for 3 or
more.

Clearly the prime numbers are better.

Thank, Hugh

-- 
Hugh E Cruickshank, Forward Software, www.forward-software.com