Oracle Solaris Virtualization Technologies Akitoshi Ozawa Katsuyuki Suzuki Masami Taoda There is an urgent need to reduce system optimization costs in the information and communications technology (ICT) infrastructure, and virtualization technology is widely expected to be key to more efficient use of system resources. A standard installation of the Oracle Solaris operating system supports server virtualization with Solaris Containers and Oracle VM Server for SPARC (VM: virtual machine) and storage virtualization with Solaris ZFS (Solaris Zettabyte File System). Solaris ZFS is a highly reliable file system that uses storage pool technology and snapshot/ cloning technology to increase disk usage efficiency. This paper discusses the domain management, resource management, and domain migration features of Oracle VM Server for SPARC and the zone management, resource management, and zone migration features of Solaris Containers. The ZFS storage pool and ZFS file system of Solaris ZFS are also introduced. 1. Introduction UNIX server features virtualization functions The information and communications that become more powerful with every update technology (ICT) infrastructure has expanded the release. Among the virtualization functions scale of systems so that business can be conducted provided as standard in SPARC Enterprise, faster and more efficiently. But as the number of this paper introduces the Oracle VM Server servers increases, it becomes more important to for SPARC (VM: virtual machine) and Solaris reduce their operating and administration costs Containers used for server virtualization2), 3) and and power consumption. the Solaris ZFS (Solaris Zettabyte File System) Server virtualization is a technique for functions for storage virtualization.4), 5) efficiently allocating system resources such as central processing units (CPUs) and memory 2. SPARC Enterprise according to the workload on each server so as to virtualization functions reduce up-front costs and enable large numbers SPARC Enterprise provides three server of servers to be integrated economically. It virtualization functions as standard through is possible to create virtual servers instantly hierarchical partitioning of the virtual server without having to wait for new hardware to be (Figure 1). delivered and to discard them when no longer 1) Hardware partition needed. Server virtualization is the first step A partition running an independent Solaris towards system optimization. OS can be configured by logically partitioning the The Oracle Solaris Operating System physical system board. The CPU and memory (Solaris OS)1) installed in Fujitsu’s SPARC can be dynamically modified in response to (scalable processor architecture) Enterprise requests for business expansion, the addition FUJITSU Sci. Tech. J., Vol. 47, No. 2, pp. 227–233 (April 2011) 227 A. Ozawa et al.: Oracle Solaris Virtualization Technologies Business A Business B Business A Business B Business A Business B Virtual OS Virtual OS OS OS OS OS OS Firmware Firmware Firmware Firmware Hardware Hardware Hardware Hardware Hardware partition Oracle VM Server for SPARC Solaris Containers Figure 1 SPARC Enterprise virtualization functions. of new business, and so on without the system Control domain Guest domain I/O domain operation being halted. Business A Business B 2) Oracle VM Server for SPARC Solaris OS Solaris OS Solaris OS Virtual Virtual Oracle VM Server for SPARC (previously service Virtual device service 6) called Sun Logical Domains) can configure Hypervisor LDC logical domains running separate instances of Physical device Physical device Hardware Solaris OS by using the SPARC hypervisor in the firmware layer to partition the physical server Figure 2 into virtual servers. The CPU, memory, and Roles of logical domains. input/output (I/O) devices are flexibly allocated by the Domain Manager. 3) Solaris Containers which the CPU, memory, and I/O devices are Solaris Containers allows the Solaris OS to logically grouped and an independent Solaris be virtually partitioned into zones that constitute OS is running in each logical domain. Each independent virtual OS environments. CPUs logical domain can be started up and shut down and memory are flexibly allocated according to independently, and up to 128 domains can be the zone’s operating conditions. I/O devices are created. Logical domains can communicate allocated when the zone is configured. with each other via hypervisor logical domain Solaris OS also provides Solaris ZFS for channels (LDCs). Virtual devices such as disks storage virtualization as a standard function. and networks access the physical devices by using The ZFS file system manages multiple physical LDCs to communicate with virtual services. disks as a storage pool. Virtualized volumes can be created by allocating the necessary space from 2.1.1 Role of logical domains the storage pool. The ZFS file system is not only Logical domains have three roles (Figure 2). durable and scalable but also easy to administer. 1) Control domain The virtualization functions of Solaris OS are A control domain is a domain operated by described below. the Domain Manager to create and administer other logical domains and allocate virtual 2.1 Oracle VM Server for SPARC resources to them. It also provides virtual device A logical domain is a virtual server in services such as virtual disk servers and virtual 228 FUJITSU Sci. Tech. J., Vol. 47, No. 2 (April 2011) A. Ozawa et al.: Oracle Solaris Virtualization Technologies switches. halted, and its memory contents are compressed 2) I/O domain and transmitted at high speed. When servers are An I/O domain can access physical I/O consolidated, a physical server can be migrated devices directly. Like a control domain, it can to a logical domain by using a physical-to- also provide virtual device services. virtual (P2V) migration tool. The configuration 3) Guest domain information of the physical server is collected A guest domain receives virtual device to create a file system image. A logical domain services from a control or I/O domain, enabling is created on the basis of this configuration itself to use virtual I/O devices such as virtual information, and the file system image is restored disks and virtual networks. on the virtual disk. 2.1.2 Resource management 2.2 Solaris Containers Resources such as virtual CPUs, memory, Solaris Containers consists of a Solaris and virtual I/O devices can be dynamically Zone function for virtually partitioning a single reconfigured while a logical domain is still OS space to make it appear as if multiple OSs operating. Furthermore, the number of virtual are running and a Solaris Resource Manager CPUs of logical domains can be automatically that flexibly allocates hardware resources such increased or decreased according to a dynamic as CPUs and memory. A Solaris Zone is a resource management policy. The dynamic virtualized OS environment that implements a resource management policy is drawn up by safe isolated environment suitable for running combining various factors such as the number of applications. Processes running in each zone are CPUs that are used, the usage ratios, upper/lower isolated and unable to affect other zones. limits, and time slots. In CPU power supply management, power savings can be achieved by 2.2.1 Solaris Zones stopping the power supply to CPUs that fall idle A Solaris system has just one global zone, as the workload changes. which is responsible for managing the entire system (Figure 3). Tasks such as the creation 2.1.3 Domain replication and administration of non-global zones and An existing domain can be replicated to enable virtual servers for new domains to be rapidly provided (provisioned) in response to Non-global zone Non-global zone user requests. If a startup disk image for a guest domain is stored in the ZFS file system, then Business A Business B it can be instantly replicated as a ZFS clone, as described below. Allocating the replicated Virtual Solaris Virtual Solaris startup disk image to another guest domain CPU CPU CPU CPU makes it unnecessary to go through the Solaris OS installation procedure. Resource pool Global zone 2.1.4 Migration Solaris OS With changes in workload, incremental Hardware growth in the number of servers and so on, it is possible to migrate a guest domain to another Figure 3 physical server. The guest domain is temporarily Solaris Containers configuration. FUJITSU Sci. Tech. J., Vol. 47, No. 2 (April 2011) 229 A. Ozawa et al.: Oracle Solaris Virtualization Technologies the allocation of physical I/O devices can be with the global zone of the destination server. performed only in the global zone. Furthermore, an active Solaris 10 OS A non-global zone is a software partition system can use the P2V function to perform of a virtual Solaris environment, in which migration by unpacking a flash archive into a applications can run without affecting other zone. The Solaris 8/9 OS system can use Solaris zones. Up to 8191 zones can be created, each of 8/9 Containers to perform migration to a Solaris which can use only its permitted file system and 10 OS zone without modifying the applications. permitted physical I/O devices. The constituent system files of a non-global 2.3 Solaris ZFS zone are copied from the global zone when the Solaris ZFS is a 128-bit file system that can zone is created. When the global zone is patched manage a practically unlimited data capacity. to modify these files, all the non-global zone files The metadata used for the administration of are also synchronously updated. a ZFS file system is dynamically allocated as required, so there is no limit to the number of file 2.2.2 Solaris Resource Manager systems or the number of files. In a conventional The Solaris Resource Manager periodically file system, the file system size is limited to the monitors resource usage and automatically physical device size. However, Solaris ZFS is not allocates resources within a specified range limited to specific physical devices because the without stopping the zone.