Tired of remapping users or applications to accommodate changes in
your storage? Virtual servers put an end to that and other storage
management challenges by eliminating the restrictive fixed resource
mapping found in traditional storage architectures. Virtual servers
allow both processing power and capacity to be allocated. Tired of
remapping users or applications to accommodate changes in your
storage? Virtual servers put an end to that and other storage
management challenges by eliminating the restrictive fixed resource
mapping found in traditional storage architectures. Virtual servers
allow both processing power and capacity to be allocated when and
where needed, and quickly redeployed to accommodate changing
requirements…
without disrupting users or migrating data. All changes to the
storage infrastructure, whether in capacity, bandwidth, or
availability, can now be transparent to users.
Virtual servers (or “vServers”) are the resource management
foundation on the ONStor NAS platform. A standard feature of all
ONStor NAS, they provide seven significant benefits:
1. Enables transparent server consolidation: Consolidate dozens of
conventional servers to a single NAS Gateway-based storage
environment without impacting users. Because vServers can appear to
users exactly as the original servers appeared (including name, IP
address, and
authentications), the migration process can be completely
transparent.
2. Real time load balancing: By redistributing vServers among NAS
Gateways, workloads can be easily balanced to eliminate
bottlenecks.
3. Seamless performance scaling: Additional NAS Gateways can be
added to the environment and quickly put to work. Simply add a NAS
Gateway and transparently relocate vServers to the new
device.
4. Quick capacity scaling: With conventional servers, adding
capacity is difficult. And once capacity is physically attached to
one server, it cannot be easily redeployed to another. vServers
allow capacity to be deployed when and where it is needed. Capacity
is contained in a single pool, shared by all vServers in the
cluster. Available capacity may be allocated to any of the vServers
on demand.
5. Granular management to meet unique SLAs: Virtual servers can be
individually configured to meet specific requirements for
performance, availability, and security. Administrators retain the
ability to respond to users’ needs while enjoying the simplicity
of a consolidated storage
environment.
6. Five-nines availability: With administrator-defined failover
policies, you can establish multiple levels of redundancy for
enterprise-class availability.
7. Anytime maintenance: When NAS Gateway maintenance is required,
all vServers can be quickly relocated to other NAS Gateways. The
device can then be taken out of service without disrupting ongoing
file services.
Overview of Virtual Server Technology
ONStor virtual servers enable seamless workload balancing,
performance scaling and device failover, all without user
disruption or data migration. In many respects, a vServer is
completely analogous to a physical server: clients and servers on
the LAN see a vServer as a complete file server with its own name,
IP address, permissions, directory structure, and attached storage.
A user is authenticated on an individual vServer just as he would
be authenticated on a physical server.
The power of the vServer lies in its mobility. Each ONStor NAS
Gateway is capable of hosting multiple vServers, all of which share
that NAS Gateway’s processing resources. Any or all of these
vServers can be relocated to other NAS Gateways to meet the
performance, availability, or maintenance objectives. These key
attributes highlight the vServer’s flexibility:
1. Flexible configuration and identity: For simple, non-disruptive
server consolidation, a vServer and all underlying storage can be
structured to look exactly like an existing server. User migration
becomes easy when the names, directory structure, and
authentications on the new vServer-based
device mimic the old device.
2. Transparent relocation: Moving a vServer from one NAS Gateway to
another is transparent to clients. A gratuitous ARP is issued to
alert devices on the network to the move. UNIX/Linux devices are
unaffected. Windows devices can reconnect automatically.
3. Anytime relocation: A vServer may be relocated among NAS
Gateways at anytime without impacting ongoing processes.
4. Granularity: You can relocate a single vServer to balance
workloads, or relocate all of the vServers to completely offload a
device for maintenance.
5. nWay clustering: ONStor supports multiple NAS Gateways in a
cluster. vServers can be moved among any of the NAS Gateways in a
cluster, eliminating the limitations of traditional clustered
pairs.
6. Flexible storage allocation: Available capacity may be allocated
to any vServer. There is no fixed mapping of storage to any
physical resource. Because storage is shared by all NAS Gateways --
and can be dynamically provisioned to any virtual server -- no data
needs to be migrated when the capacity of a volume is
increased.
With these attributes, vServers redefine file server architecture
and eliminate the restrictions that accompany the traditional
approach.
Using Virtual Servers
A vServer is a collection of NAS Gateway resources that allow file
services to be provided for clients over an IP network. A vServer
groups IP connectivity, authentication, export interfaces, and file
systems to make them usable by clients.
Basic Tips&Limitations
vServers are simple to create and manage. Here are a few
basics:
• vServers are created and configured either through the command
line interface or via the NAS Gateway Manager GUI.
• At least one vServer must be created in order to start file
services.
• Multiple vServers can reside on a physical NAS Gateway but
multiple NAS Gateways may not share the same vServer (the vServer
can be moved to another NAS Gateway, but will not exist on more
than one NAS Gateway at a time).
• A maximum of 32 vServers are currently supported per
cluster.
The Management vServer
A single management vServer is automatically created on each NAS
Gateway1, and it is always the first vServer to be configured. It
does not perform file serving functions, but is instead dedicated
to these management tasks:
• Persistent connectivity to domain controllers (this enables the
NAS Gateway to remain authenticated).
• Continuous availability of core dump functionality.
• Persistent connection to an external NTP server, if an external
NTP server exists in the network.
• Continuous availability of a management volume.
• Connection to other NAS Gateways in a cluster.
The management vServer does not function as a file serving device.
It is automatically created, cannot be disabled, and will not
failover to another NAS Gateway during a failure event – every
NAS Gateway has its own management vServer. In a cluster, the IP
address for the management virtual server should be configured on
the same subnet as other nodes in the cluster.
Creating and Configuring vServers
This is the process for bringing a new virtual server on
line:
1. Create the new vServer via either the CLI or the GUI. A new
vServer is always created in a disabled state which allows all
vServer parameters to be configured before the device is brought on
line.
2. Assign a name, IP address (or multiple IP addresses; up to 4
addresses may be assigned), domain and WINS server address (if
applicable).
3. Specify the vServer as “protected” or “not protected.”
By default, a vServer is protected which means the vServer will be
automatically relocated to another NAS Gateway in the cluster if
the original host NAS Gateway becomes unavailable.
4. Assign volumes to the vServer and establish shares for CIFS and
NFS clients. Each vServer can serve files to a mix of Windows, UNIX
or Linux clients and servers.
5. Enable the AutoCreate function. This feature allows the NAS
Gateway to automatically create a user’s home directory share in
a vServer. AutoCreate shares are treated as a CIFS share that are
automatically exported to users whenever they log in. Users have
automatic access to their own directories. This eliminates the need
to configure individual shares for each user.
6. Enable the new vServer. Manually Re-locating a vServer
For load balancing, maintenance, or performance scaling purposes
virtual servers can be manually relocated between NAS Gateways in a
cluster, regardless of whether the vServers are protected or
unprotected. When the move is completed, the entire virtual server
configuration, including the IP
interface(s), volumes, and shares configured on the virtual server
are retained. There is no migration of data and no user
disruption.
Virtual Servers Details Dialog Consolidation with
vServers
ONStor’s NAS Gateways provide an
excellent solution for file server consolidation. Individual
Windows servers can effectively be migrated to the NAS Gateway by
configuring a vServer to appear to the users as the original
server, eliminating user disruption. Typical practical
consolidation ratios are 20 to 40 Windows file servers per NAS
Gateway, which provides the opportunity for significant hardware
and management cost savings.
Summary
By transforming physical NAS
Gateways into a pool of logical file server resources, vServers
offer a powerful solution to some of the most pressing storage
problems:
• Reduce server proliferation
• Simplify file sharing among Windows, UNIX and Linux users
• Streamline capacity or performance additions
• Centralize backup to reduce process complexity and boost
reliability
ONStor’s virtual server technology provides the key to the
enterprise-enabled NAS. vServers deliver the management power and
flexibility to take the pain out of providing enterprise-wide
mission-critical file services, while putting an end to user and
data migration.
