[CentOS] Minimum RAM for CentOS7

Mon Sep 8 17:05:24 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Mon, Sep 8, 2014 at 11:36 AM, Valeri Galtsev
<galtsev at kicp.uchicago.edu> wrote:
> On Mon, September 8, 2014 9:44 am, Les Mikesell wrote:
>> On Mon, Sep 8, 2014 at 3:38 AM, Mihamina Rakotomandimby
>> <mihamina.rakotomandimby at rktmb.org> wrote:
>>>> If you have 1.000 or 10.000 machines it*is*  a reason to
>>>> think about every fucking dollar per machine you can save each month.
>>> You could *just* *install* with 1GB and then get down to 512 at runtime.
>> First, if you are running 10,000 machines with 512K RAM, you are doing
>> something really, really weird or you just like managing a lot of
>> machines that can't do very much each - and supplying a lot more power
>> than you would need for fewer, more capable hosts.
>> But, if you have even more than a few, you are probably already doing
>> some sort of image installs.  So just install on a machine or VM with
>> 1GB, then use ReaR or Clonezilla to back it up and restore onto the
>> target boxes.   Or for brute force, use dd to copy the drive and swap
>> them into place.
> ... which will be a lot of drive swapping for 1000 or 10000 machines. With
> this number of machines the only workable option I can think of is netboot
> + kickstart (with hard drive then network boot order in BIOS so no need to
> change anything after system is installed)... But it is true what was
> mentioned 1000+ weak machines are unlikely to be able to pay their
> electric bills.

Drive swapping is pretty easy on servers with hotswap bays.  If you
can rack the machines you would be able to swap the drives.   But,
Clonezilla with the DRBL server  has a multicast option that will
install the same image on a bunch of machines at once - and it is
fairly agnostic about the OS it is loading so it is useful in a
heterogeneous environment.

   Les Mikesell
      lesmikesell at gmail.com