OpenVZ is an open source virtualization technology for Linux which utilities containers to run separate Linux based operating systems on a single machine. OpenVZ is typically used as it touts a low overhead, of around 1-3% of CPU, compared to other virtualization technologies.

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Which virtualization platforms should I choose, Xen or OpenVZ?

I am upgrading my shared hosting to VPS hosting, mainly to just add server administration skills to my development skills, so I'm facing a lot of new choices just signing up. I need to choose a ...
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1answer
2k views

Is LXC secure enough for VPS hosting?

Right now I'm using Linux VServer for VPS hosting. But it's lacking some functionality I need (ex. cpu usage virtualization, quota support for guests, etc.) so I'm thinking about switching to OpenVZ ...
7
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1answer
473 views

ip6tables rules are completely ignored inside OpenVZ container

We have set up IPv6 networking on openvz using bridged veth devices. The IPv6 traffic to and from the VEs works fine. ip6tables works on the HN and iptables work on the VE. Inside the VE we can set ...
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2answers
7k views

Apache reaching MaxClients and locking the server

I currently have an Apache2 server running with mpm-prefork and mod_php on a OpenVZ VPS with 512M real / 1024M burstable RAM (no swap). After running some tests, I found that the maximum process size ...
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5answers
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Cannot create Java VM on OpenVZ

I'm constantly encountering an error related to Java and certificates on my Ubuntu server running in OpenVZ when installing things from apt-get. I'm pretty sure it has to do with how Java allocates ...
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3answers
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iptables nat does not exist

Today my iptables nat on the host system stopped working and I have no clue what happend! (That's very bad, I know) All commands are executed as root user. If I run $ iptables -t nat -L I get the ...
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2answers
4k views

What exactly is AVAHI?

CentOS 5.2 My VPS host rebooted (checking with host support now) and I noticed the following in /var/log/messages Aug 28 11:57:52 echo avahi-daemon[21633]: **Found user 'avahi' (UID 70) and group ...
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2answers
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Nagios (Return code of 141 is out of bounds) on random services

We have had Nagios running on one of our servers with out any problems for a while but lately we get (Return code of 141 is out of bounds). The load on the server raised because we gone online with ...
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2answers
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OpenVZ: limit number of cpu cores per VE

Is there a way of limiting number of cpu cores seen from inside a VE? I have an eight core server, but I want my VE to see only one particular core. Thanx!
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3answers
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Which Apache package is best for mod_wsgi Django application?

In Ubuntu (and Debian, and other distro) there is a few Apache packages (mpm-event, mpm-prefork, mpm-worker). Which is the most suitable for hosting Django mod_wsgi application on single CPU server? ...
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6answers
914 views

What do you recommend? OpenVZ or Xen DomU?

I’m looking for a new server at the moment and a fitting virtualization solution. On my recent server I’m using VMware server but don’t what this one anymore as it is very very slow. I have the ...
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4answers
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PHP unable to allocate memory

On my way to the office this morning, every website on our shared VPS started giving the same error (several times, not the typical memory_limit error which is fatal): Warning: Unknown: Unable to ...
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2answers
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How do I enable swap file on my server?

I've followed this but when I run:- #swapon /swapfile1 I get::- swapon: /swapfile1: swapon failed: Operation not permitted The system is extremely slow with 1GB of RAM trying to run ...
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4answers
4k views

OpenVZ multiple networks on CTs

I have Hardware Node (HN) which has 2 physical interfaces (eth0, eth1). I'm playing with OpenVZ and want to let my containers (CTs) have access to both of those interfaces. I'm using basic ...
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3answers
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How to de-duplicate data for OpenVZ/LXC on Linux?

I want to setup multiple similar containers and I want to have de-duplication. The only solution I'm thinking of is to use OpenSolaris ZFS and share zfs volume with NFSv4 ro iSCSI target and create ...
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1answer
2k views

Software Interrupts CPU time is high and keeps growing

My system is a Debian 6.0.3 x86_64 box w/kernel 2.6.32-5-openvz-amd64, it hosts a number of OpenVZ containers. I have recently migrated from LXC/newer kernel from backports repo to the stable OpenVZ ...
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3answers
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How to mount glusterfs inside a OpenVZ container?

glusterfs uses fuse to mount a glusterfsd volume, wich works fine on any hardwarenode without virtualization. But, I now try to mount the device inside a container glusterfs --debug -f ...
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2answers
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Advice on most fitting choice of virtualization platform: Xen | OpenVZ | KVM | other? What suits the purpose best?

I am aware of the multitude of virtualization threads here but they all seem to be oldish and i'd like to have a brand new one ready for 2012. I'm currently evaluating Xen, OpenVZ and KVM for ...
4
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1answer
275 views

RAM burst, myth or reality?

Often when buying a VPS, we are faced with a number of features. These include the RAM. In XEN virtualization RAM and swap is (or should be) dedicated. In OpenVZ, how important is "burst"? I ask ...
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4answers
646 views

Private Cloud: Debian and OSS vs vmware vSphere, which is best for corporate use? [closed]

I'm hoping someone can shed some light regarding the current state of virtualization on Debian. Since I like my information first-hand, i thought I'd ask here for some real-world use cases. I am ...
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2answers
4k views

OpenVZ: share a folder between containers

I want to share a directory from an OpenVZ container to another container, how I could do that? do a symlink from /vz/private/109/common-stuff to /vz/private/108/common-stuff ? bind mount ...
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2answers
2k views

OpenVZ vs Xen, how much difference in performance?

There is a Xen vs. KVM in performance question on ServerFault. What will be the speed difference if the choice is between Xen and OpenVZ? Searching for such benchmarks does not show any results ...
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1answer
6k views

OpenVPN server running on openvz. How to write iptables rule without masquerade?

I am configuring a VPS which is running on openvz as an OpenVPN server using a tun interface. I am having some trouble with the iptables rule as MASQUERADE is not available. If MASQUERADE were ...
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2answers
875 views

Why is my cron daemon is being killed every few minutes?

As of about a week ago, my cron daemon refuses to stay running. I'm using Debian 6 x64 on an OpenVZ virtual machine. Running something like pgrep cron shows that the daemon isn't running. I start the ...
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1answer
1k views

permission denied for chmod as root

I need to manage a customer's openvz guest (latest debian squeeze 64 bit). Now when I try to do a chmod 0750 /root as root it gives me Permission denied. This really puzzles me, as I thought root can ...
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3answers
905 views

OpenVZ - share files between virtual machines (VEs)?

Is there any way to share a directory of files between virtual machines running in OpenVZ? My particular use case is that I want to have a shared YUM cache directory, for when they all need to run ...
3
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1answer
610 views

“kernel: Cannot read proc file system: 1 - Operation not permitted” — millions of such messages each minute in kern.log on OpenVZ VPS? [closed]

I'm seeing repeated never ending such messages in kern.log on my OpenVZ ubuntu 12.04 server. Mar 2 06:23:33 localhost kernel: Cannot read proc file system: 1 - Operation not permitted. Mar 2 ...
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1answer
262 views

Changing time or offsetting it in OpenVZ contained server

I am trying to run a VPS, a Debian box contained in an OpenVZ container. Obviously, I cannot use time --set or any such command, as the time must be set via the parent node. The owner of the parent ...
3
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1answer
7k views

How can I tell who/what shutdown my CentOS VPS?

CentOS 5.7 VPS (running on OpenVZ) My VPS shut down this morning and I'm not sure why. I contacted my VPS host and they indicated that the server "was off". They powered it back on but I'm confused ...
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1answer
1k views

How to limit memory for VE on openvz

I need to configure only one vps in a openvz node. The node will have only one vps. I need help to configure the memory limits correctly. The node have 4GB memory with 4GB swap. I would like to ...
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3answers
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Java VM problem in OpenVZ

I bought a vps for hosting my java needs. But I can't run java on it. Everything about java is correctly installed but when I try to run java ("java -version" forexample) I get this error : Error ...
3
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1answer
183 views

What's the expected behaviour of multiple hostname entries with different IP addresses in /etc/hosts?

I know this has been discussed in several places, but there doesn't seem to be a definitive answer yet - at least not for RHEL 6. I'm just hoping someone might be able to point to how it's working so ...
3
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1answer
142 views

OpenVZ has vzctl exec, what is the equivelent for lxc

I'm switching from OpenVZ to lxc. The one thing that is really bugging me is that I can't find a lxc alternative to vzctl exec. Before on OpenVZ I could do vzctl exec 1033 restart nginx. Now, all I ...
3
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2answers
1k views

How to properly set CPU Units for OpenVz VEs

According to all the sources I read (openvz wiki, various mailinglists, forums, ..) the values of the cpuunits settings are relative to each other. So when all are equal and the system is busy, all ...
3
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1answer
254 views

Is it safe for a single directory/file to be served by two separate samba daemons simultaneously?

The situation is this: I have a Debian server which acts as a web/mail server as well as an Internet gateway for a small office. All the externally available services run on OpenVZ virtual ...
3
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2answers
2k views

Iptables port forwarding on OpenVZ CEntOS container

I am trying to setup a simple port forwarding on an OpenVZ container that is running CentOS 5.5. When I run a command I get errors. iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT ...
3
votes
1answer
900 views

Does our VPS have its kmemsize limit set too low?

Short Version: Are there any official guidelines on what the kmemsize barrier and limit should be set to for a container in Virtuozzo/OpenVZ intended to be used as a Web server? We've found posts ...
2
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1answer
900 views

How to run fsck on a simfs filesystem under openvz

How do you do a fsck on a simfs filesystem under OpenVZ? You're supposed to not run fsck on a mounted FS. Can you just fsck the image (/vz/private/100 or whatever it's called)? Sorry I can't tag ...
2
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4answers
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OpenVZ vs KVM for Linux VMs

Hardware: Intel® Core™ i7-920, 12 GB DDR3 RAM, 2 x 1500 GB SATA-II HDD (no SoftRaid because Proxmox developers don't support softraid and they are sure you'll run into problems) Software: Proxmox VE ...
2
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2answers
165 views

upgrading kernel from 2.6.27 to 2.6.32

I have an openvz server, currently running on linux-2.6.27-openvz-kiprensky.1-r1 Now, I'm upgrading server and part of the upgrade is kernel upgrade. Now, I'm offered ...
2
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3answers
1k views

Best way to benchmark linux virtualization solutions

I'd like to run some benchmarks on linux virtualization solutions (namely Xen, KVM and OpenVZ) and I'm currently thinking about how to set up the test environment. My current approach would be the ...
2
votes
3answers
399 views

Shell access for a KVM VM

I would like to access my KVM VM with a shell. I created it via proxmox 2.3, Ubuntu 12.04 is installed on it via an official template. I would like to find the same command as vzctl enter ...
2
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1answer
208 views

openVZ VPS spam

i have an openvz vps,, and i use to run only openvpn server.. but one day, my datacenter told me they suspended my vps because it was sending spam? well im not using smtp or stuff on my vps, its just ...
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2answers
493 views

Assign /112 IPv6 range to OpenVZ VPS

I have a /48 IPv6 and would like to chop these up into /112's that I can assign to my VPSes. I know how to assign them manually, e.g. vzctl set 1 --ipadd ipv6IP --save But how could I assign, for ...
2
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2answers
138 views

Why would you use Xen as opposed to OpenVZ for trusted Linux-only host/guests? [closed]

Every time I need to create VPSs out of one of our machines, I (re)think the virtualization technologies, and seem to end up with OpenVZ being the most suitable for performance reasons when all I want ...
2
votes
1answer
699 views

PPTP installation on CentOS 5 not working (Kernel support for PPP?)

I am trying to get PPTP installation up and running on my VPS. I have followed various guides, however, I am unable to connect to the VPN once it’s setup. I checked my VPS’ /var/log/messages and I ...
2
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2answers
2k views

Screen - No more PTYs - Cannot start screen's on Debian VPS

I've gotten a newly imaged Debian 6 32 bit VPS. While configuring I tried to test screen as a number of my scripts run using it. Root has no problem running screen. But of course this is ...
2
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2answers
384 views

apparmor not working ubuntu 11.04 insize OpenVZ

so it seems I have everything installed, but apparmor_status gives "apparmor module is not loaded." Also some apparmor scripts check for presence of /sys/module/apparmor and it is not there... Any ...
2
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1answer
73 views

Why is a remote IP redirecting to a local server?

I've got a rack full of Linux servers that host OpenVZ containers and for some reason when I attempt to connect to a certain remote IP from inside a few of the OpenVZ containers (using telnet, for ...
2
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1answer
174 views

Linux: File is not shown in ls but cannot be touched with message “File exists”

I can remember creating this file but it disapeard. But not completely: root@XXX:/etc/vz/conf# ls -al total 0 drwxr-x--- 2 root www-data 0 Okt 1 16:04 . drwxr-x--- 2 root www-data 0 Okt 1 16:04 .. ...