Re: [Vserver] OCS Inventory

2007-03-17 Thread Daniel W. Crompton

On 3/16/07, Daniel Hokka Zakrisson <[EMAIL PROTECTED]> wrote:

Daniel W. Crompton wrote:

After reading Jean-Marc's answer I thought it could also be the fact
that you might just need to create /dev/mem.


You absolutely never ever want to do that, if you care the least about the
guest being secure... /dev/mem would give it complete access to the
contents of your RAM.


Seriously if you care about your guest being secure you make sure that
the host doesn't have physical network access. If you want to be able
to run certain programs in a guest you sometimes need rights which are
available to only the host. That's the whole point of caps.

I want to make it clear that I have no idea what the OCS program does,
but if you want to run it in a guest then you need to be able to
access /dev/mem. Making the guest insecure is the price you have to
pay. Having network access for a machine means risking remote attacks
it's the price you pay.

I hardly run anything on my host systems besides syslog and sshd,
practically everything runs in a guest. Some guests have caps that
give it almost full access to the host system on other guests you
don't even have write access to the disk or a compiler. (It logs to
the host's syslog anyway.) The level of access you need in a guest
determines who access is given to, not whether you do something or
not.

The only thing you "absolutely never ever" want to do is give somebody
you don't trust physical access to the host, anything else is a
question of need.

D.


blaze your trail

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Re: [Vserver] OCS Inventory

2007-03-17 Thread Daniel Hokka Zakrisson
Daniel W. Crompton wrote:
> On 3/16/07, Daniel Hokka Zakrisson <[EMAIL PROTECTED]> wrote:
>> Daniel W. Crompton wrote:
>>> After reading Jean-Marc's answer I thought it could also be the fact
>>> that you might just need to create /dev/mem.
>>
>> You absolutely never ever want to do that, if you care the least about
>> the
>> guest being secure... /dev/mem would give it complete access to the
>> contents of your RAM.
>
> Seriously if you care about your guest being secure you make sure that
> the host doesn't have physical network access. If you want to be able
> to run certain programs in a guest you sometimes need rights which are
> available to only the host. That's the whole point of caps.

Which should not be taken as lightly as "you just need to create XYZ".
It's something that essentially voids the entire virtualization/isolation
that Linux-VServer provides...

-- 
Daniel Hokka Zakrisson
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Re: [Vserver] OCS Inventory

2007-03-17 Thread Daniel W. Crompton

On 3/17/07, Daniel Hokka Zakrisson <[EMAIL PROTECTED]> wrote:

You absolutely never ever want to do that, if you care the least about the
guest being secure... /dev/mem would give it complete access to the
contents of your RAM.

Seriously if you care about your guest being secure you make sure that
the host doesn't have physical network access. If you want to be able
to run certain programs in a guest you sometimes need rights which are
available to only the host. That's the whole point of caps.

Which should not be taken as lightly as "you just need to create XYZ".
It's something that essentially voids the entire virtualization/isolation
that Linux-VServer provides...


You are right that I was a little flippant in my remark that one
should just create /dev/mem, and should have mentioned the security
implications. My remark did contain reservation you didn't pick-up on.
"You might just need to create XYZ" carries a very different message
than "you just need to create XYZ." In this case "might" means that it
is possible that you would need to do XYZ, I realize that this
reservation could be missed in a cursory reading.

However that doesn't however negate the fact that to run OCS Agent as
is in a guest you might just need to create /dev/mem.

regards,

D.


blaze your trail

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Re: [Vserver] OCS Inventory

2007-03-17 Thread harry

in the same sense...

disable all firewalls, open up your telnet port and allow passwordless 
rootlogin on all your machines

or pull the plug

those are the only possibilities, right?

Daniel W. Crompton wrote:

Seriously if you care about your guest being secure you make sure that
the host doesn't have physical network access. If you want to be able
to run certain programs in a guest you sometimes need rights which are
available to only the host. That's the whole point of caps.

I want to make it clear that I have no idea what the OCS program does,
but if you want to run it in a guest then you need to be able to
access /dev/mem. Making the guest insecure is the price you have to
pay. Having network access for a machine means risking remote attacks
it's the price you pay.

I hardly run anything on my host systems besides syslog and sshd,
practically everything runs in a guest. Some guests have caps that
give it almost full access to the host system on other guests you
don't even have write access to the disk or a compiler. (It logs to
the host's syslog anyway.) The level of access you need in a guest
determines who access is given to, not whether you do something or
not.

The only thing you "absolutely never ever" want to do is give somebody
you don't trust physical access to the host, anything else is a
question of need.

--
harry
aka Rik Bobbaers

K.U.Leuven - LUDIT  -=- Tel: +32 485 52 71 50
[EMAIL PROTECTED] -=- http://people.linux-vserver.org/~harry

Nobody notices when things go right.

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm

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Re: [Vserver] OCS Inventory

2007-03-17 Thread Herbert Poetzl
On Sat, Mar 17, 2007 at 02:37:39PM +, Daniel W. Crompton wrote:
> On 3/17/07, Daniel Hokka Zakrisson <[EMAIL PROTECTED]> wrote:
> >>>You absolutely never ever want to do that, if you care the least about 
> >>>the
> >>>guest being secure... /dev/mem would give it complete access to the
> >>>contents of your RAM.
> >>Seriously if you care about your guest being secure you make sure that
> >>the host doesn't have physical network access. If you want to be able
> >>to run certain programs in a guest you sometimes need rights which are
> >>available to only the host. That's the whole point of caps.
> >Which should not be taken as lightly as "you just need to create XYZ".
> >It's something that essentially voids the entire virtualization/isolation
> >that Linux-VServer provides...
> 
> You are right that I was a little flippant in my remark that one
> should just create /dev/mem, and should have mentioned the security
> implications. My remark did contain reservation you didn't pick-up on.
> "You might just need to create XYZ" carries a very different message
> than "you just need to create XYZ." In this case "might" means that it
> is possible that you would need to do XYZ, I realize that this
> reservation could be missed in a cursory reading.
> 
> However that doesn't however negate the fact that to run OCS Agent as
> is in a guest you might just need to create /dev/mem.

you might want to check with the source (of OCS Agent)
what the application actually does with /dev/mem

best,
Herbert

> regards,
> 
> D.
> 
> 
> blaze your trail
> 
> --
> redhat
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Re: [Vserver] Vserver CPU limit question

2007-03-17 Thread Herbert Poetzl
On Fri, Mar 16, 2007 at 06:54:26PM -0700, Albert Mak (almak) wrote:
> Hi,
> 
> I have Linux (2.6.14.3 Kernel) with Vserver 2.0.1 and testing the CPU
> limit capabilities. I have 2 vserver contexts both running CPU intensive
> app capable of using up 100% CPU, I am setting up on vserver to limit 1
> context to 10% CPU  and the 2nd to 80% CPU, both using flags sched_prio.
> I am seeing CPU usage split 50/50 between the 2 contexts. I repeated the
> same test using sched_hard with the same result (kernel VSERVER_HARDCPU
> config set to y). I am expecting to see at least the CPU usage close to
> the Vserver limits.
> 
> Have I got the wrong settings or some other issues. Your help is really
> appreciated.
> 
> -Albert
> 
> top - 18:37:04 up 26 min,  1 user,  load average: 2.04, 1.40, 0.62
> Tasks: 127 total,   3 running, 124 sleeping,   0 stopped,   0 zombie
> Cpu(s): 98.7% us,  1.3% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi,
> 0.0% si
> Mem:513084k total,   115660k used,   397424k free,10200k buffers
> Swap:0k total,0k used,0k free,39332k cached
> 
>   PID USER  PR  NI  VIRT  RES  SHR S %CPU %MEMTIME+  COMMAND
>  6616 root  20   0  1332  228  184 R 49.8  0.0   2:23.12
> exceed_cpu_limi
>  6513 root  20   0  1336  232  184 R 48.1  0.0   2:43.79
> exceed_cpu_limi
> 
> -bash-2.05b# vps
>   PID CONTEXT TTY  TIME CMD
>  3672 0 MAIN  pts/000:00:00 bash
>  6513 2 APP1  pts/000:03:01 exceed_cpu_limi
>  6616 3 APP2  pts/000:02:40 exceed_cpu_limi
>  7655 1 ALL_PROC  pts/000:00:00 vps
>  7656 1 ALL_PROC  pts/000:00:00 ps
> 
> -bash-2.05b# pwd
> /etc/vservers/APP1
> -bash-2.05b# cat flags
> sched_prio

you want to add sched_hard here if you want hard
scheduling, the prio scheduler will only adjust
priorities according to the token buckets ...

I'd also suggest to use a more recent kernel
(and probably Linux-VServer patch) than this one
as the scheduler was enhanced quite a lot in 2.2.x

> -bash-2.05b# cat schedule
> 80
> 100
> 200
> 50
> 140
> dummy
> 
> -bash-2.05b# pwd
> /etc/vservers/APP2
> -bash-2.05b# cat flags
> sched_prio
> -bash-2.05b# cat schedule
> 10
> 100
> 200
> 50
> 140
> dummy
> 
> -bash-2.05b# cat /proc/virtual/2/sched
> Token:   140
> FillRate:  1
> Interval:100
> TokensMin:50
> TokensMax:   140
> PrioBias:  0
> VaVaVoom: -5
> cpu 0: 229674 71 0
> 
> -bash-2.05b# cat /proc/virtual/3/sched
> Token:   140
> FillRate: 10
> Interval:100
> TokensMin:50
> TokensMax:   140
> PrioBias:  0
> VaVaVoom: -5
> cpu 0: 217275 54 0

looks like none of the token buckets is active
here, what does the /proc/virtual/2/status show?

TIA,
Herbert

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Re: [Vserver] Re: Oops with rejecting routes in vservers instance

2007-03-17 Thread Herbert Poetzl
On Thu, Mar 15, 2007 at 07:38:44PM +0100, Herbert Poetzl wrote:
> On Thu, Mar 15, 2007 at 12:18:12PM +0100, Asier Baranguán wrote:
> > Asier Baranguán escribió:
> > 
> > >>~~~
> > >>quite ancient ... could you try something like 2.6.18-4 or
> > >>even better 2.6.19.7-vs2.2.0-rc17 and tell me if you see
> > >>the same issues?
> > >>
> > >>will try to recreate it here ...
> > >
> > >Oops.
> > >
> > >Kernel 2.16.38-vs2.0.3-rc1 and same problem... 

okay, was actually easy to recreate, thanks to your
information and testing ... turned out to be an
issue present in recent versions too ...

> > >Is there any fix for this in the 'stable' 2.6.16 kernel?

yep, we updated the 2.6.16 kernel to 2.6.16.43 and
the patch to 2.0.3-rc2, you can find it here:

http://vserver.13thfloor.at/Experimental/patch-2.6.16.43-vs2.0.3-rc2.diff

thanks for spotting,
Herbert

> > Emm... I want to say "any fix for the 2.0.3rc1 release 
> > of the 'stable' 
> > 2.6.16 kernel"
> 
> will check that tonight or tomorrow, when I get
> around digging out that old kernel :)
> 
> best,
> Herbert
> 
> > Thanks
> 
> > begin:vcard
> > fn;quoted-printable:Asier Barangu=C3=A1n
> > n;quoted-printable:Barangu=C3=A1n;Asier
> > org;quoted-printable:ELPA Gesti=C3=B3n
> > adr;quoted-printable;dom:;;c/ Henao 4 - 3=C2=BAA;Bilbao;Bizkaia;48009
> > email;internet:[EMAIL PROTECTED]
> > title:A/P
> > tel;work:944.23.01.66
> > tel;fax:944.23.01.78
> > x-mozilla-html:FALSE
> > url:http://www.elpagestion.com
> > version:2.1
> > end:vcard
> > 
> 
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RE: [Vserver] Vserver CPU limit question

2007-03-17 Thread Albert Mak (almak)
Hi Herbert

Here is the output of /proc/virtual/2/status as requested Both
context 2 and 3 have the same setting.

-bash-2.05b# cat /proc/virtual/2/status 
UseCnt: 7
Tasks:  2
Flags:  000202020210
BCaps:  354c24ff
CCaps:  0101
Ticks:  0

Thanks.

-Albert
-Original Message-
From: Herbert Poetzl [mailto:[EMAIL PROTECTED] 
Sent: Saturday, March 17, 2007 11:36 AM
To: Albert Mak (almak)
Cc: vserver@list.linux-vserver.org
Subject: Re: [Vserver] Vserver CPU limit question

On Fri, Mar 16, 2007 at 06:54:26PM -0700, Albert Mak (almak) wrote:
> Hi,
> 
> I have Linux (2.6.14.3 Kernel) with Vserver 2.0.1 and testing the CPU 
> limit capabilities. I have 2 vserver contexts both running CPU 
> intensive app capable of using up 100% CPU, I am setting up on vserver

> to limit 1 context to 10% CPU  and the 2nd to 80% CPU, both using
flags sched_prio.
> I am seeing CPU usage split 50/50 between the 2 contexts. I repeated 
> the same test using sched_hard with the same result (kernel 
> VSERVER_HARDCPU config set to y). I am expecting to see at least the 
> CPU usage close to the Vserver limits.
> 
> Have I got the wrong settings or some other issues. Your help is 
> really appreciated.
> 
> -Albert
> 
> top - 18:37:04 up 26 min,  1 user,  load average: 2.04, 1.40, 0.62
> Tasks: 127 total,   3 running, 124 sleeping,   0 stopped,   0 zombie
> Cpu(s): 98.7% us,  1.3% sy,  0.0% ni,  0.0% id,  0.0% wa,  0.0% hi, 
> 0.0% si
> Mem:513084k total,   115660k used,   397424k free,10200k
buffers
> Swap:0k total,0k used,0k free,39332k
cached
> 
>   PID USER  PR  NI  VIRT  RES  SHR S %CPU %MEMTIME+  COMMAND
>  6616 root  20   0  1332  228  184 R 49.8  0.0   2:23.12
> exceed_cpu_limi
>  6513 root  20   0  1336  232  184 R 48.1  0.0   2:43.79
> exceed_cpu_limi
> 
> -bash-2.05b# vps
>   PID CONTEXT TTY  TIME CMD
>  3672 0 MAIN  pts/000:00:00 bash
>  6513 2 APP1  pts/000:03:01 exceed_cpu_limi
>  6616 3 APP2  pts/000:02:40 exceed_cpu_limi
>  7655 1 ALL_PROC  pts/000:00:00 vps
>  7656 1 ALL_PROC  pts/000:00:00 ps
> 
> -bash-2.05b# pwd
> /etc/vservers/APP1
> -bash-2.05b# cat flags
> sched_prio

you want to add sched_hard here if you want hard scheduling, the prio
scheduler will only adjust priorities according to the token buckets ...

I'd also suggest to use a more recent kernel (and probably Linux-VServer
patch) than this one as the scheduler was enhanced quite a lot in 2.2.x

> -bash-2.05b# cat schedule
> 80
> 100
> 200
> 50
> 140
> dummy
> 
> -bash-2.05b# pwd
> /etc/vservers/APP2
> -bash-2.05b# cat flags
> sched_prio
> -bash-2.05b# cat schedule
> 10
> 100
> 200
> 50
> 140
> dummy
> 
> -bash-2.05b# cat /proc/virtual/2/sched
> Token:   140
> FillRate:  1
> Interval:100
> TokensMin:50
> TokensMax:   140
> PrioBias:  0
> VaVaVoom: -5
> cpu 0: 229674 71 0
> 
> -bash-2.05b# cat /proc/virtual/3/sched
> Token:   140
> FillRate: 10
> Interval:100
> TokensMin:50
> TokensMax:   140
> PrioBias:  0
> VaVaVoom: -5
> cpu 0: 217275 54 0

looks like none of the token buckets is active here, what does the
/proc/virtual/2/status show?

TIA,
Herbert

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