Open Stack

Hi, I'd like you to take a look at this patch for potential
DocImpact.
https://review.openstack.org/18290

Log:
commit ae302e1cce31f3cf57e6c981c299e23f480c9e9c
Author: gholt <z-launchpad at brim.net>
Date:   Tue Dec 18 03:31:57 2012 +0000

    Added fallocate_reserve option
    
    Some systems behave badly when they completely run out of space. To
    alleviate this problem, you can set the fallocate_reserve conf value
    to a number of bytes to "reserve" on each disk. When the disk free
    space falls below this amount, fallocate calls will fail, even if the
    underlying OS fallocate call would succeed. For example, a
    fallocate_reserve of 10737418240 (10G) would make all fallocate calls
    fail, even for a zero-byte files, when the disk free space falls
    under 10G.
    
    The default fallocate_reserve is 0, meaning "no reserve", and so the
    software behaves exactly as it always has unless you set this conf
    value to something non-zero.
    
    Also fixed ring builder's search_devs doc bugs.
    
    DocImpact
    
    Change-Id: I8db176ae0ca5b41c9bcfeb7cb8abb31c2e614527