Provided by:
vzctl_3.0.22-14ubuntu2_i386 
NAME
vzctl - utility to control a Virtual Environment.
SYNOPSIS
vzctl [flags] create veid --ostemplate name] [--config name] [--private
path] [--root path] [--ipadd addr] [--hostname name]
vzctl [flags] set veid [parameters] [--save]
vzctl [flags] destroy | mount | umount | start | stop | restart |
status | enter veid
vzctl [flags] exec | exec2 veid command [arg ...]
vzctl runscript veid script
vzctl --help | --version
DESCRIPTION
Utility vzctl runs on Hardware Node (HN) and performs direct
manipulations with Virtual Environments (VEs).
Virtual Environments can be referred to by either numeric veid or by
name (see --name option). Note that VE ID <= 100 are reserved for
OpenVZ internal purposes.
OPTIONS
Flags
These flags can be used with almost any option.
--quiet
Disables logging to log file and screen.
--verbose
Sets logging level to maximum value.
Setting VE parameters
set veid [parameters] [--save]
This command sets various VE parameters. If flag --save is given,
parameters are saved in VE configuration file vps.conf(5). If VE
is currently running, vzctl applies these parameters to VE.
The following options can be used with set command.
Miscellaneous parameters
--onboot yes|no
Sets whether this VE will be started during system boot up. VE will
not be auto-started during system boot up unless this parameter is
set to yes.
--root path
Sets the path to root directory for this VE. This is essentially a
mount point for VE root. Value must contain string $VEID, which
will be substituted with numeric VE ID. Changing this parameter is
not recommended, better edit vz(5) global configuration file.
--userpasswd user:password
Sets password for the given user in VE, creating the user if it
does not exists. Note that this option is not saved in
configuration file at all (so --save flag is useless), it is
applied to VE (by modifying its /etc/passwd and /etc/shadow files).
In case VE root is not mounted, it is automatically mounted, then
all appropriate file changes are applied, then it is unmounted.
Note that VE area should be created before using this option.
--disabled yes|no
Disable VE start. To force the start of a disabled VE, use vzctl
start with --force option.
--name name
Add a name for a VE. The name can later be used in subsequent calls
to vzctl in place of veid.
--setmode restart|ignore
Whether to restart a VE after applying any parameters requiring
that the VE be restarted for those to take effect.
Network related parameters
--ipadd addr
Adds IP address to a given VE. Note that this option is
incremental, so addr are added to already existing ones.
--ipdel addr | all
Removes IP address addr from a VE. If you want to remove all
addresses, use --ipdel all.
--hostname name
Sets VE hostname. vzctl writes it to the appropriate file inside a
VE (distribution-dependent).
--nameserver addr
Sets DNS server IP address for a VE. If you want to set several
nameservers, you should do it at once, so use --nameserver option
multiple times in one call to vzctl, as all the name server values
set in previous calls to vzctl gets overwritten.
--searchdomain name
Sets DNS search domains for a VE. If you want to set several search
domains, you should do it at once, so use --searchdomain option
multiple times in one call to vzctl, as all the search domain
values set in previous calls to vzctl gets overwritten.
--netif_add ifname[,mac,host_ifname,host_mac]
Adds a virtual ethernet device (veth) to a given VE. Here ifname is
the ethernet device name in the VE, mac is its MAC address,
host_ifname is the ethernet device name on the host, and host_mac
is its MAC address. MAC addresses should be in the format like
XX:XX:XX:XX:XX:XX. All parameters except ifname are optional and
are automatically generated if not specified.
Interface configuration
The following options can be used to reconfigure the already-
created virtual ethernet interface. To select the interface to
configure, use --ifname name option.
--mac XX:XX:XX:XX:XX:XX - MAC address of interface inside VE.
--host_ifname name - interface name for virtual interface in VE0.
--host_mac XX:XX:XX:XX:XX:XX - MAC address of interface in VE0.
--netif_del dev_name|all
Removes virtual ethernet device from VE. If you want to remove all
devices, use all.
Resource limits
The following options sets barrier and limit for various user
beancounters. Each option requires one or two arguments. In case
of one argument, vzctl sets barrier and limit to the same value. In
case of two colon-separated arguments, the first is a barrier, and
the second is a limit. Each argument is either a number, a number
with a suffix, or a special value unlimited.
Arguments are in items, pages or bytes. Note that page size is
architecture-specific, it is 4096 bytes on IA32 platform.
You can also specify different suffixes for set parameters (except
for the parameters which names start with num). For example, vzctl
set veid --privvmpages 5M:6M should set privvmpages’ barrier to 5
megabytes and its limit to 6 megabytes.
Available suffixes are:
g, G -- gigabytes.
m, M -- megabytes.
k, K -- kilobytes.
p, P -- pages (page is 4096 bytes on x86 architecture, other
architectures may differ).
You can also specify the literal word unlimited in place of a
number. In that case the corresponding value will be set to
LONG_MAX, i. e. the maximum possible value.
--numproc items[:items]
Maximum number of processes and kernel-level threads. Setting the
barrier and the limit to different values does not make practical
sense.
--numtcpsock items[:items]
Maximum number of TCP sockets. This parameter limits the number of
TCP connections and, thus, the number of clients the server
application can handle in parallel. Setting the barrier and the
limit to different values does not make practical sense.
--numothersock items[:items]
Maximum number of non-TCP sockets (local sockets, UDP and other
types of sockets). Setting the barrier and the limit to different
values does not make practical sense.
--vmguarpages pages[:pages]
Memory allocation guarantee. This parameter controls how much
memory is available to a VE. The barrier is the amount of memory
that VE’s applications are guaranteed to be able to allocate. The
meaning of the limit is currently unspecified; it should be set to
unlimited.
--kmemsize bytes[:bytes]
Maximum amount of kernel memory used. This parameter is related to
--numproc. Each process consumes certain amount of kernel memory -
16 KB at leas, 30-50 KB typically. Very large processes may consume
a bit more. It is important to have a certain safety gap between
the barrier and the limit of this parameter: equal barrier and
limit may lead to the situation where the kernel will need to kill
VE applications to keep the kmemsize usage under the limit.
--tcpsndbuf bytes[:bytes]
Maximum size of TCP send buffers. Barrier should be not less than
64 KB, and difference between barrier and limit should be equal to
or more than value of numtcpsock multiplied by 2.5 KB.
--tcprcvbuf bytes[:bytes]
Maximum size of TCP receive buffers. Barrier should be not less
than 64 KB, and difference between barrier and limit should be
equal to or more than value of numtcpsock multiplied by 2.5 KB.
--othersockbuf bytes[:bytes]
Maximum size of other (non-TCP) socket send buffers. If VE
processes needs to send very large datagrams, the barrier should be
set accordingly. Increased limit is necessary for high performance
of communications through local (UNIX-domain) sockets.
--dgramrcvbuf bytes[:bytes]
Maximum size of other (non-TCP) socket receive buffers. If VE
processes needs to send very large datagrams, the barrier should be
set accordingly. The difference between the barrier and the limit
is not needed.
--oomguarpages pages[:pages]
Guarantees against OOM kill. Under this beancounter the kernel
accounts the total amount of memory and swap space used by the VE
processes. The barrier of this parameter is the out-of-memory
guarantee. If the oomguarpages usage is below the barrier,
processes of this VE are guaranteed not to be killed in out-of-
memory situations. The meaning of limit is currently unspecified;
it should be set to unlimited.
--lockedpages pages[:pages]
Maximum number of pages acquired by mlock(2).
--privvmpages pages[:pages]
Allows controlling the amount of memory allocated by the
applications. For shared (mapped as MAP_SHARED) pages, each VE
really using a memory page is charged for the fraction of the page
(depending on the number of others using it). For "potentially
private" pages (mapped as MAP_PRIVATE), VE is charged either for a
fraction of the size or for the full size if the allocated address
space. It the latter case, the physical pages associated with the
allocated address space may be in memory, in swap or not physically
allocated yet.
The barrier and the limit of this parameter control the upper
boundary of the total size of allocated memory. Note that this
upper boundary does not guarantee that VE will be able to allocate
that much memory. The primary mechanism to control memory
allocation is the --vmguarpages guarantee.
--shmpages pages[:pages]
Maximum IPC SHM segment size. Setting the barrier and the limit to
different values does not make practical sense.
--numfile items[:items]
Maximum number of open files. Setting the barrier and the limit to
different values does not make practical sense.
--numflock items[:items]
Maximum number of file locks. Safety gap should be between barrier
and limit.
--numpty items[:items]
Number of pseudo-terminals (PTY). Note that in OpenVZ each VE can
have not more than 255 PTYs. Setting the barrier and the limit to
different values does not make practical sense.
--numsiginfo items[:items]
Number of siginfo structures. Setting the barrier and the limit to
different values does not make practical sense.
--dcachesize bytes[:bytes]
Maximum size of filesystem-related caches, such as directory entry
and inode caches. Exists as a separate parameter to impose a limit
causing file operations to sense memory shortage and return an
errno to applications, protecting from memory shortages during
critical operations that should not fail. Safety gap should be
between barrier and limit.
--numiptent num[:num]
Number of iptables (netfilter) entries. Setting the barrier and
the limit to different values does not make practical sense.
--physpages pages[:pages]
This is currently an accounting-only parameter. It shows the usage
of RAM by this VE. Barrier should be set to 0, and limit should be
set to unlimited.
CPU fair scheduler parameters
These parameters control CPU usage by VE.
--cpuunits num
CPU weight for a VE. Argument is positive non-zero number, which
passed to and used in kernel fair scheduler. The larger the number
is, the more CPU time this VE get. Maximum value is 500000, minimal
is 8. Number is relative to weights of all the other running VEs.
If cpuunits not specified default value 1000 ia used.
You can set CPU weight for VE0 (hardware node itself) as well (use
vzctl set 0 --cpuunits num). Usually, OpenVZ initscript
(/etc/init.d/vz) takes care of setting this.
--cpulimit num[%]
Limit of CPU usage for the VE, in per cent. Note if the computer
has 2 CPUs, it has total of 200% CPU time. Default CPU limit is 0
(no CPU limit). --cpus num sets number of CPUs available in the
VE.
Memory output parameters
This parameter control output of /proc/meminfo inside a VE
--meminfo none
No /proc/meminfo virtualization (the same as on host system).
--meminfo mode:value
Configure total memory output in a VE. Free memory is evaluated
accordingly to the mode being set.
You can use the following modes for mode:
pages:value - sets total memory in pages
privvmpages:value - sets total memory as privvmpages * value
Default is privvmpages:1.
Iptables control parameters
--iptables name
Restrict access to iptables modules inside a VE (by default
all iptables modules that are loaded in the host system are
accessible inside a VE).
You can use the following values for name: iptable_filter,
iptable_mangle, ipt_limit, ipt_multiport, ipt_tos, ipt_TOS,
ipt_REJECT, ipt_TCPMSS, ipt_tcpmss, ipt_ttl, ipt_LOG,
ipt_length, ip_conntrack, ip_conntrack_ftp,
ip_conntrack_irc, ipt_conntrack, ipt_state, ipt_helper,
iptable_nat, ip_nat_ftp, ip_nat_irc, ipt_REDIRECT, xt_mac,
ipt_owner.
Network devices control parameters
--netdev_add name
move network device from VE0 to a specified VE
--netdev_del name
delete network device from a specified VE
Disk quota parameters
--diskspace num[:num]
sets soft and hard disk quotas, in blocks. First parameter
is soft quota, second is hard quota. One block is currently
equal to 1Kb. Also suffixes G, M, K can be specified (see
Resource limits section for more info).
--diskinodes num[:num]
sets soft and hard disk quotas, in i-nodes. First parameter
is soft quota, second is hard quota.
--quotatime seconds
sets soft overusage time limit for disk quota (also known as
grace period).
--quotaugidlimit num
sets maximum number of user/group IDs in a VE for which disk
quota inside the VE will be accounted. If this value is set
to 0, user and group quotas will not be accounted inside the
VE.
Note that if you have previously set value of this parameter
to 0, changing it while the VE is running will not take
effect.
Mount option
--noatime yes|no
Sets noatime flag (do not update inode access times) on file
system.
Capability option
--capability capname:on|off
Sets capability inside a VE. Note that setting capability
when the VE is running does not take immediate effect;
restart VE in order for changes to take effect. Note a VE
has default set of capabilities, thus any operation on
capabilities is "logical and" with the default capability
mask.
You can use the following values for capname: chown,
dac_override, dac_read_search, fowner, fsetid, kill, setgid,
setuid, setpcap, linux_immutable, net_bind_service,
net_broadcast, net_admin, net_raw, ipc_lock, ipc_owner,
sys_module, sys_rawio, sys_chroot, sys_ptrace, sys_pacct,
sys_admin, sys_boot, sys_nice, sys_resource, sys_time,
sys_tty_config, mknod, lease, setveid, ve_admin.
WARNING: setting some of those capabilities may have far
reaching security implications, so do not do it unless you
know what you are doing. Also note that setting setpcap:on
for a VE will most probably lead to inability to start it.
Device access management
--devnodes device:r|w|rw|none
Give the VE an access (r - read, w - write, rw - read write,
none - no access) to a device designated by the special file
/dev/device. Device file is created in VE by vzctl.
--devices b|c:major:minor|all:[r|w|rw|none]
Give the VE an access to a block or character device
designated by its major and minor numbers. Device file have
to be created manually.
Features management
--features name:on|off
Enable or disable a specific VE feature. Known features
are: sysfs, nfs.
Apply config
--applyconfig name
Read VE parameters from the VE sample configuration file
/etc/vz/conf/ve-name.conf-sample, and apply them, if --save
option specified save to the VE config file. The following
parameters are not changed: HOSTNAME, IP_ADDRESS,
OSTEMPLATE, VE_ROOT, and VE_PRIVATE.
--applyconfig_map name
Apply VE config parameters selected by name group, now only
name argument supported. Restore VE name based on NAME
variable in VE configuration file.
I/O priority management
--ioprio priority
Assigns I/O priority to VE. Priority range is 0-7. The
greater priority is, the more time for I/O activity VE has.
By default each VE has priority of 4.
Checkpointing and restore
Checkpointing is a feature of OpenVZ kernel which allows to save
a complete state of a running VE, and to restore it later.
chkpnt veid [--dumpfile name]
This command saves a complete state of a running VE to a
dump file, and stops the VE. If an option --dumpfile is not
set, default dump file name /vz/dump/Dump.veid is used.
restore veid [--dumpfile name]
This command restores a VE from dump file created by the
chkpnt command.
Performing VE actions
create veid [--ostemplate name] [--config name] [--private path]
[--root path] [--ipadd addr] [--hostname name]
Creates a new VE area. This operation should be done once,
before the first start of the VE.
If the --config option is specified, values from example
configuration file /etc/vz/conf/ve-name.conf-sample are put
into the VE configuration file. If this VE configuration
file already exists, it will be removed.
You can use --root path option to sets the path to the mount
point for the VE root directory (default is VE_ROOT
specified in vz(5) file). Argument can contain string $VEID,
which will be substituted with numeric VE ID.
You can use --private path option to set the path to
directory in which all the files and directories specific to
this very VE are stored (default is VE_PRIVATE specified in
vz(5) file). Argument can contain string $VEID, which will
be substituted with numeric VE ID.
You can use --ipadd addr option to assign an IP address to a
VE. Note that this option can be used multiple times.
You can use --hostname name option to set a host name for a
VE.
destroy
Removes a VE private area by deleting all files, directories
and configuration file of this VE.
start [--wait] [--force]
Mounts (if necessary) and starts a VE. Unless --wait option
is specified, vzctl will return immediately; otherwise an
attempt to wait till the default runlevel is reached will be
made by vzctl.
Specify --force if you want to start a VE which is disabled
(see --disabled).
stop
Stops and unmounts a VE.
restart
Restarts a VE, i.e. stops it if it is running, and starts
again.
status
Shows a VE status. Basically this is a line with five words
separated by spaces. First word is literally VEID. Second
word is the numeric VE ID. Third word is showing whether
this VE exists or not, it can be either exist or deleted.
Fourth word is showing the status of the VE filesystem, it
can be either mounted or unmounted. Fifth word shows if the
VE is running, it can be either running or down.
This command can also be usable from scripts.
mount
Mounts VE private area.
umount
Unmounts VE private area. Note that stop does umount
automatically.
exec veid command
Executes command in a VE. Environment variables are not set
inside the VE. Signal handlers may differ from default
settings. If command is -, commands are read from stdin.
exec2 veid command
The same as exec, but return code is that of command.
runscript
Run specified shell script in a VE, if the VE is not
runnning it will be started.
enter
Enters into a VE. This option is a back-door for host root
only.
Other options
--help
Prints help message with a brief list of possible options.
--version
Prints vzctl version.
DIAGNOSTICS
Returns 0 upon success.
EXAMPLES
To create and start "basic" VE with ID of 1000, using fedora-
core-5 OS template, and IP address of 192.168.10.200:
vzctl create 1000 --ostemplate fedora-core-5 --config
vps.basic
vzctl set 1000 --ipadd 192.168.10.200 --save
vzctl start 1000
To set number of processes barrier/limit to 80/100, and PTY
barrier/limit to 16/20 PTYs:
vzctl set 1000 --numproc 80:100 -t 16:20 --save
To execute command ls -la in this VE:
vzctl exec 1000 /bin/ls -la
To execute command pipe ls -l / | sort in this VE:
vzctl exec 1000 ’ls -l / | sort’
To stop this VE:
vzctl stop 1000
To permanently remove this VE:
vzctl destroy 1000
FILES
/etc/vz/vz.conf
/etc/vz/conf/veid.conf
/proc/vz/veinfo
/proc/vz/vzquota
/proc/user_beancounters
/proc/fairsched
SEE ALSO
vz.conf(5), vps.conf(5), vzquota(8),
LICENSE
Copyright (C) 2000-2007, SWsoft. Licensed under GNU GPL v2.