On Sun, Feb 22, 2004 at 08:56:06PM +0200, Alex Lyahkov wrote:
> ? ???, 22.02.2004, ? 19:27, Herbert Poetzl ?????:
> > Hi Folks!
> > 
> > some people asked me about the 'advanced' features
> > FreeVPS provides over the Linux-Vserver patches ...
> > 
> > so here is the 'list' provided at the FreeVPS site
> > http://www.freevps.com/docs/faq.html#General3
> > and my comments/questions to that ...
> > 
> > > FreeVPS extends the original Linux VServer functionality. 
> > > FreeVPS implementation include FreeVPS kernel patch and FreeVPS 
> > > tools. Together they add the following new features to VPS:
> > 
> > > * Limits on:
> > >   - total memory usage
> > >   - resident memory size
> > 
> > in Linux-VServer, VM is accounted and enforced, RSS only accounted, 
> > I don't know what 'total memory usage' means ...
> Current version (that in release candidate state, release been in few
> days later) implement new variant memory accounting - based on rmaps.
> Old variant implement has same with VServer model memory accounting - 
> count total address space.

this is for 2.6.x or 2.4.x with or without the rmap
patches?

> > >   - number of processes
> > 
> > is accounted and enforced, as all limits, can be changed at runtime
> > 
> > >   - disk usage quota
> > 
> > this is handled by the Quota Disk Limit (included in the quota patch)
> > 
> > >   - file handles
> > >   - tcp sockets
> > 
> > both are not accounted yet, and not limited.
> > 
> > > * Advanced context management:
> > >   - create/destroy a context
> > >   - enter a context
> > 
> > well, that is basic functionality ...
> > 
> > >   - running status
> > 
> > vserver-stat and /proc/virtual provide this ...
> > 
> > >   - enable/disable creating new processes in a context
> > >   - send signal to all processes in context
> > 
> > this is done with the vkill command (via syscall since 1.1.6)
> > 
> > > * inodes attributes management:
> > >   - context tag
> > 
> > xid tagging is used by Quota Disk Limits and Per Context Quota
> > and it comes in 3 flavours (UID32/GID16, UID24/GID24 and UID32/GID32)
> > 
> > >   - flag for files shared between contexts
> > 
> > don't know what this is, but might be the IUNLINK flag
> Not. This flag allow read owned by other context when reader. Base
> functionality for uninfected vps. I don`t know how you have read inode
> from context 0 in context 5, for example.

xid=0 files are visible and accessable for xid!=0
only xid=N (with N>0) files are not accessible in
context M (N != M)

> > >   - immutable flag
> > 
> > well if that is what it says, then it's basic linux stuff
> > 
> > ---
> > 
> > so after this shoot out ;) the following differences
> > seem to remain:
> > 
> > > * Limits on:
> > >   - resident memory size
> > >   - file handles
> > >   - tcp sockets
> > 
> > > * Advanced context management:
> > >   - enable/disable creating new processes in a context
> > 
> > and I don't know the FreeVPS status of the following
> > Linux-VServer features:
> > 
> >     - vroot device (security)
> What ? only for diskquota? FreeVPS have correctly virtual root, and not
> affected with all chroot atacks. 

well, that won't help much to prevent the direct
access to a shared block device, you wan't to run
quota tools on, but I assume you do something else
to prevent unwanted access ...

> >     - Token Bucket scheduler stuff (Sam)
> FreeVPS have load balacer and planig add CPU QoS.

any details about those plans?

> >     - uts_name modifications (stealth)
> FreeVPS have it more above with VServer.
> >     - procfs security
> >     - uptime virtualization 
> >     - reboot userspace helper 
> > 
> Linux VServer not have
> 1) virtual network devices with bandwidth shaper

that is correct, but similar can be done with tc 
and iptables/netfilter

> 2) private routing tables includes private loopback.
> 3) private routing caches 

correct

> (2 and 3 need for correctly select packet source address.)

hmm, well, it seems that isn't an issue anymore ..

> 4) Correctly (rmap based) memory accounting. Herbert please try use you
> memory accounting at high load web server with apache1 or other fork
> based programs.

will/should this change anything? what do you expect?
what did your 'test' show in this regard?

> 5) Correctly created private namespace - not affected with any chroot
> exploit. 

this is done in experimental (with alpha tools) and
mostly in userspace (only the enter requires kernel help)

> 6) CAP_NET_ADMIN/CAP_SYS_RESOURCE can be used inside vps without
> security problems. 

which means?

TIA,
Herbert

PS: did you change your last name from Lyashkov to 
Lyahkov or is/was it 'just' incorrectly spelled?

PPS: would like to have a look at a recent FreeVPS
version, what do I need and where do I get it?

> -- 
> Alex Lyahkov <[EMAIL PROTECTED]>
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