UID_MIN & GID_MIN changed

[Ondrej Vasik]

On Wed, 2011-05-25 at 10:55 +0200, Peter Vrabec wrote:
> Hi,
> 
> On Tuesday, May 24, 2011 05:25:44 PM Toshio Kuratomi wrote:
> > On Tue, May 24, 2011 at 1:59 AM, Peter Vrabec <pvrabec at redhat.com> wrote:
> > > Hi all,
> > > 
> > > I'd like to inform you that I have changed UID_MIN & GID_MIN from 500 to
> > > 1000 in upgraded shadow-utils.
> > > 
> > > Where?
> > > /etc/login.defs.
> > > shadow-utils-4.1.4.3-1.fc16
> > > 
> > > I suppose UID/GID_MIN=1000 is more common(other distros, upstream). We
> > > are not in situation that 500 IDs for system accounts ought to be enough
> > > for anybody. Actually, it was not 500.It was 299 because range 0-200 is
> > > for reserved IDs. There are 799 non reserved IDs for system accounts
> > > available after this change.
> > 
> > This change should be made as a Feature for F16 and needs some
> > thought/coordination put behind it.  There's several issues that I
> > see:
> > 
> > * AFAIK, we actually have not run into the 500 uid limit yet (although
> > it is a bit low to be comfortable)
> > *  AFAIK, we've only allocated the range 0-100 for reserved IDs.
> > * The 0-100 reserved IDs are actually the pain point that we need to
> > deal with, not the dynamic system ids in the 101-499 range.
> We use 0-200 for reserved IDs  since
> http://lists.fedoraproject.org/pipermail/devel/2009-April/028740.html

Actually since July 2009 - there are no free uid/gid's left bellow 100.
And yes, I'm giving static assignments only for system accounts which
potentially can handle/own sensitive information or do communicate with
other systems - so I rejected some requests for static ID's reservation.

> 
> > * We don't know how many, if any IDs this actually gets us for the
> > dynamic range because any site that has already filled the 500-1000
> > UID range won't gain any extra dynamic system account through this
> > change.
> > * This could potentially break sites that are currently using the
> > 500-1000 UID range and rely on the order of allocation of UIDs for
> > their users on new machines matching with the UIDs on old machines.
> > (For instance, NFS UIDs on filesystems matching between a box
> > installed with RHEL5 and a box that gets newly installed with F16).
> > 
> > -Toshio
> 
> I'm not against wider announcement. I'm just not sure what is the right way - 
> F16 Feature/Release Notes/ .... ? We can also annouce the 200 limit for 
> reserved IDs. ;)

Probably makes sense :) ... even some ID sanity validator/checker might
be good idea for this "feature".

Ondrej Vasik