zones(5) Standards, Environments, and Macros zones(5)
zones - Solaris application containers
The zones facility in Solaris provides an isolated environment for running applications. Processes running in a zone are prevented from
monitoring or interfering with other activity in the system. Access to other processes, network interfaces, file systems, devices, and
inter-process communication facilities are restricted to prevent interaction between processes in different zones.
The privileges available within a zone are restricted to prevent operations with system-wide impact. See privileges(5).
You can configure and administer zones with the zoneadm(1M) and zonecfg(1M) utilities. You can specify the configuration details a zone,
install file system contents including software packages into the zone, and manage the runtime state of the zone. You can use the zlogin(1)
to run commands within an active zone. You can do this without logging in through a network-based login server such as in.rlogind(1M) or
An alphanumeric name and numeric ID identify each active zone. Alphanumeric names are configured using the zonecfg(1M) utility. Numeric IDs
are automatically assigned when the zone is booted. The zonename(1) utility reports the current zone name, and the zoneadm(1M) utility can
be used to report the names and IDs of configured zones.
A zone can be in one of several states:
CONFIGURED Indicates that the configuration for the zone has been completely specified and committed to stable storage.
INCOMPLETE Indicates that the zone is in the midst of being installed or uninstalled, or was interrupted in the midst of such
INSTALLED Indicates that the zone's configuration has been instantiated on the system: packages have been installed under the
zone's root path.
READY Indicates that the "virtual platform" for the zone has been established. Network interfaces have been plumbed, file
systems have been mounted, devices have been configured, but no processes associated with the zone have been
RUNNING Indicates that user processes associated with the zone application environment are running.
SHUTTING_DOWN Indicates that the zone is being halted. The zone can become stuck in one of these states if it is unable to tear
DOWN down the application environment state (such as mounted file systems) or if some portion of the virtual platform
cannot be destroyed. Such cases require operator intervention.
Process Access Restrictions
Processes running inside a zone (aside from the global zone) have restricted access to other processes. Only processes in the same zone are
visible through /proc (see proc(4) or through system call interfaces that take process IDs such as kill(2) and priocntl(2). Attempts to
access processes that exist in other zones (including the global zone) fail with the same error code that would be issued if the specified
process did not exist.
Processes running within a non-global zone are restricted to a subset of privileges, in order to prevent one zone from being able to per-
form operations that might affect other zones. The set of privileges limits the capabilities of privileged users (such as the super-user or
root user) within the zone. The list of privileges available within a zone can be displayed using the ppriv(1) utility. For more informa-
tion about privileges, see privileges(5).
The set of devices available within a zone is restricted, to prevent a process in one zone from interfering with processes in other zones.
For example, a process in a zone should not be able to modify kernel memory using /dev/kmem, or modify the contents of the root disk. Thus,
by default, only a few pseudo devices considered safe for use within a zone are available. Additional devices can be made available within
specific zones using the zonecfg(1M) utility.
The device and privilege restrictions have a number of effects on the utilities that can run in a non-global zone. For example, the eep-
rom(1M), prtdiag(1M), and prtconf(1M) utilities do not work in a zone since they rely on devices that are not normally available.
Each zone has its own section of the file system hierarchy, rooted at a directory known as the zone root. Processes inside the zone can
access only files within that part of the hierarchy, that is, files that are located beneath the zone root. This prevents processes in one
zone from corrupting or examining file system data associated with another zone. The chroot(1M) utility can be used within a zone, but can
only restrict the process to a root path accessible within the zone.
In order to preserve file system space, sections of the file system can be mounted into one or more zones using the read-only option of
the lofs(7FS) file system. This allows the same file system data to be shared in multiple zones, while preserving the security guarantees
supplied by zones.
NFS and autofs mounts established within a zone are local to that zone; they cannot be accessed from other zones, including the global
zone. The mounts are removed when the zone is halted or rebooted.
Zones can be assigned logical network interfaces, which can be used to communicate over the network. These interfaces are configured using
the zonecfg(1M) utility. The interface is removed when the zone is halted or rebooted. Only logical interfaces can be assigned to a zone.
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Availability |SUNWcsu |
zlogin(1), zonename(1), in.rlogind(1M), sshd(1M), zoneadm(1M), zonecfg(1M), getzoneid(3C), kill(2), priocntl(2), ucred_get(3C), get-
zoneid(3C), proc(4), attributes(5), privileges(5), crgetzoneid(9F)
SunOS 5.10 13 Apr 2004 zones(5)