The IBM TotalStorage SAN Volume Controller -- What It Does
Definition of Virtual Disks Above the Disk Controller Adds New
Scope
The SAN Volume Controller has been designed to combine unique and
scalable hardware and software to accomplish Logical Unit virtualization
above the storage disk controller level. This allows the creation of
Virtual Disks that can span multiple, disparate disk subsystems that are
under SAN Volume Controller management, and allows Virtual Disks to be
composed with specific attributes, according to performance,
availability, or cost requirements. Storage virtualization also has the
potential to help simplify maintenance and installation operations, and
enable a central, unified and consistent view of all managed storage
under the SAN Volume Controller.
Mapping RAID Array storage to Block Level Virtualization
Storage systems make available SCSI Logical Units representing the
RAID-controlled storage. The automatic discovery process of the SAN
Volume Controller is designed to find the available SCSI Logical Units
and allow them to be mapped to Managed Disks in a one-to-one
relationship. Managed Disks can then be user-defined into Managed Disk
Groups -- combining all the available disk extents. The user may then
create Virtual Disks, which are associated with each Managed Disk Group
and user-assigned to host systems. Thus, all available disk space in a
Managed Disk Group is made accessible through Virtual Disks, and Virtual
Disks appear to the host as SCSI Logical Units supporting a SCSI command
set.
The user can choose to configure any Virtual Disk to be mapped to
Managed Disks in one of three ways:
- Image mode, to help simplify the transition of storage from a non-
virtualized to a virtualized environment without copying the actual data
from one physical location to another
- Sequential mode, to help maintain the physical connection between the
extents within a given Virtual Disk when placed on physical media (even
if the data is subsequently moved to another physical location)
- Striped mode, whereby the extents within a given Virtual Disk are
distributed evenly among multiple SCSI Logical Units within the Managed
Disk Group
The user will then be in a position to leverage the virtualized
storage environment and address the shortcomings that are inherent in
isolated conventional SAN arrays, such as stranded capacity, varied
intelligence levels, data migration limitations, and management
idiosyncrasies.
The Efficiency Advantages of True Pools
The establishment of Virtual Disks that can span the entire range of
storage in the SAN has the potential to aid in the establishment of
Virtual Disks with precision of purpose, such as performance,
availability, cost, or other attributes, and also helps to maximize the
potential for finding appropriate available storage in the desired
category -- no matter which disk subsystem controls the physical storage.
This has the potential to result in a higher utilization of disk storage
resources.
The volume management efficiency possible on this basis has the
potential to minimize the amount of unused capacity throughout the
installation. Also, with this architecture, less complex, lower cost,
RAID/storage devices are useable to support advanced copy and management
functions. The inherent efficiency of virtual Logical Unit blocking
allows storage pools to maintain uniform performance, even after many
creates and deletes.
System Components, Architecture, and Configurations
The SAN Volume Controller operating environment is based on a Linux
2.4 kernel and is supported by dual IBM 2145 Storage Engines. The SAN
Volume Controller is intended for incorporation into existing customer
SANs, while the IBM TotalStorage SAN Integration Server, another member
of the TotalStorage Virtualization Family, provides a self-contained
solution integrating the SAN Volume Controller with dual UPS, Brocade SAN
switches, and TotalStorage FAStT storage -- for implementation either as
a new SAN or to meet expanding SAN storage requirements.
SAN Volume Controller nodes have been architected to be implemented in
pairs, with one or more pairs constituting a cluster. The pairs of nodes
operate in a dual-active configuration, with each node in a pair backing
up the other, and the cluster configuration shared across the cluster.
Data written to the nodes is duplicated across caches in both nodes and
both nodes are protected by UPSs. This design is intended to avoid
single points of failure and enable maintenance to take place
concurrently with application I/O.
Both systems require a minimum of two nodes, and are expandable to
four nodes per cluster. Nodes must be added in pairs. The architecture
of SAN Volume Controller is designed to be scaled beyond four nodes per
cluster. The architecture allows a single cluster to manage up to two
petabytes of usable storage, regardless of the number of node pairs in
that cluster. Each engine is a customized IBM eServer xSeries server,
with four gigabytes of read/write memory. The majority of this memory is
available for use as read/write cache; any memory used as write cache is
mirrored in the partner engine of the engine pair.
Physical Disk Storage System Support
Storage system support is available for the IBM FAStT models 200, 500,
600, 700, and 900.
Storage system support is available for the IBM Enterprise Storage
Server (ESS) models 2105-F20 and 2105-800.
Host Attachments
The IBM TotalStorage SAN Volume Controller supports RISC-based hosts
running the IBM AIX, Sun Solaris, or Hewlett-Packard HP-UX, and
Intel-based hosts running Microsoft Windows (Windows NT or Windows 2000
Advanced Server) and Red Hat Linux Advanced Server operating systems.
Switch Support
The SAN Volume Controller supports selected models of Brocade, McData,
and INRANGE fibre channel SAN switches.
Current Technical Information
Current host attachment, switch, and controller support information,
including required microcode levels, will be maintained at:
http://www.ibm.com/storage/support/2145
Important Functions and Features
Dynamic Data Migration capability
Powerful data migration functions are part of the base virtualization
software of the SAN Volume Controller. These functions enable
administrators to move storage from one device to another and perform
load balancing across storage without taking data offline and without
losing the availability of the data. This capability is intended to help
reduce or eliminate the planned downtime required to migrate data from
obsolete or end-of-lease storage devices onto newer devices.
Optional Advanced Copy Services
In addition to the Data Migration capabilities included in the base
virtualization software, the SAN Volume Controller offers a complement of
advanced copy functions, including FlashCopy and Synchronous Peer-to-Peer
Remote Copy (PPRC). FlashCopy can be performed for all storage under SAN
Volume Controller management (assigned to a Virtual Disk). PPRC is
available for host applications in the AIX and Windows 2000 environments
using IBM FAStT storage systems. Configuration guidelines and current
support summaries can be found at:
http://www.ibm.com/storage/support/2145
With conventional SAN disk arrays, copy operations are limited to in-
box or like-box-to-like-box scenarios. With SAN-wide virtualization,
FlashCopy (point-in-time) copies can be performed between separate
subsystems within the same cluster and can use differing physical disk
subsystems. To aid in disaster recovery, Remote Copy can be performed
between clusters at different locations. The distance between locations
will affect the performance achieved by Remote Copy. Generally,
locations that are closer together will perform better. Remote Copy can
also be performed within a cluster. This may be useful for test or
production prototyping purposes. Virtual Disk to Managed Disk mappings
can be changed without application disruption, and workload rebalance via
data migration can be simply and efficiently invoked.
These advanced copy functions include architected failover support.
They can be used in conjunction with both LAN-free and server-free
backups, while supporting continuous access to the data.
Consistency Groups
In order to allow copy functions to be managed in a coordinated way
across a number of Virtual Disks, it is possible to create a single
entity for management, known as a Consistency Group. Where an
application issues dependent writes that span multiple virtual disks, it
is the use of Consistency Groups that will provide volume consistency,
even during a rolling disaster.
For example, a set of volumes on a primary cluster could form a
Consistency Group. A set of Remote Copy relationships between the
primary volumes and a set of corresponding secondary volumes could be
treated atomically by the use of a Consistency Group. The SAN Volume
Controller software is designed to make it easy to form and manage
Consistency Group relationships. Consistency Groups can be created,
modified, and deleted with succinct, direct commands. Consistency Groups
may also be established for FlashCopy mappings of Virtual Volumes that
span multiple Virtual Disks -- enabling the FlashCopy operation on
multiple Virtual Disks to take place as an atomic operation.
I/O Metering and I/O Statistics
SAN Volume Controller provides a range of facilities for monitoring,
reporting, and controlling the I/Os received by the cluster. This is
designed to allow the bandwidth and throughput resources available to the
enterprise to be allocated on a per-business-unit basis, or per
application basis, enabling some control of throughput allocation, in
addition to storage space.
Statistics are maintained on a per SCSI Logical Unit basis. That is,
a separate set of counters is maintained for each Virtual Disk, on I/Os
received on each SAN Volume Controller port, from each host port. The
following statistics are maintained:
- Count of read I/Os and write I/Os
- Count of blocks read, and blocks written
I/O Governing
It is possible to constrain I/O operations such that a system is
constrained in the amount of I/O it can perform with respect to a given
Virtual Disk in a period of time. This can be used to satisfy some
quality-of-service constraints or contractual obligations (e.g., a
customer agrees to pay for I/Os performed, but will not pay for I/Os
beyond a certain rate).
Ease of Configuration
With the unified view made possible by the SAN Volume Controller
software, a more unified approach to storage volume management is
possible. A highly-effective automatic hardware discovery function
brings newly installed storage into immediate view. The modularity of
the system also supports nondisruptive installation of additional nodes
and capacity.
Focus on Availability with Avoidance of Downtime for Planned
Outages
Highly Available Clustered Configuration
The redundant design of the SAN Volume Controller allows nondisruptive
software upgrades and leverages proven multipathing software from IBM.
Dual Caches
In addition to the dual components design, the architecture of the SAN
Volume Controller and SAN Integration Server supports high availability
while maintaining performance with read and write caches. Each engine's
cache is independent. Cached writes are mirrored in the paired engine,
before being acknowledged to the application server. The engines are in
turn supported by independent UPS power. This permits cache write
operations to be committed immediately, while supporting the availability
demanded by application servers.
Superior RAS
The SAN Volume Controller has been designed to provide:
- Extensive error logging and analysis functions that serve to
facilitate rapid problem determination
- An internal "watchdog" timer that facilitates automatic engine
restart and re-admission to the cluster without operator intervention
- Service pages that are accessible via the Web, enabling efficient and
flexible operations.
The Command Line Interface (CLI) for the SAN Volume Controller is
accessible via Ethernet, as an alternative or backup to normal
Web-accessed CIM/GUI interface control.
The master console provides a unified point of service for the entire
cluster, helping to reduce time lost to device/controller path
identification and location. The master console also provides access to
a readily available Virtual Private Network connection initiated by the
customer. The master console also provides IBM Call Home and remote
support capabilities, to help support fast, efficient service.
Focus on Economy and Simplicity
Scalability and Price
Scalable software and hardware helps you to both address your current
needs and to grow your data storage in keeping with business demands.
Storage that is leveraged across multiple devices by virtue of virtual
Logical Units enables use of lower cost devices at recovery sites, and,
therefore, can help lower overall cost of backup and recovery operations.
SAN Volume Controller Storage Software is licensed to the cluster in
tiers, according to the amount of storage virtualized and managed by that
cluster. Data Migration functions are included as part of the base
software. Additional optional advanced copy features are also priced in
tiers according to the amount of storage served by each feature. (The
effective tier for each advanced copy service feature may be selected
independently from each other and from that of the total base virtualized
storage tier, so long as the capacity level tier for either advanced copy
feature does not exceed the capacity tier level of licensed base
virtualized storage.)
SAN Volume Controller hardware and software tiers may thus be
independently scaled, according to performance, storage growth, and other
customer functional requirements.
The licensed SAN Volume Controller Storage Software (5639-VC1) runs on
the SAN Volume Controller Storage Engine cluster, either as a stand-alone
cluster or within the SAN Integration Server solution.
Powerful, Centralized Storage Management Interface
The IBM TotalStorage SAN Volume Controller Storage Software provides a
Common Information Model (CIM) Agent that supports the open standards
(SNIA SMIS), and allows the SAN Volume Controller to be managed by
standard-compliant Storage Resource Management applications. The SAN
Volume Controller software also provides a Web-accessible GUI, supporting
flexible and rapid access to storage management information.
This software runs on the master console that is dedicated to support
the SAN Volume Controller hardware and software. The master console also
provides residence for Tivoli SAN Manager, as well as the call-home,
remote support, and other tools utilized with the Virtualization Family.
The entitled version of Tivoli SAN Manager provided in the Tivoli Bonus
Pack supports up to 64 ports per enterprise. See Limitations.
SAN Volume Controller Version 1, Release 1, Modification 1 Adds
New Support
The IBM TotalStorage SAN Volume Controller Storage Software Version
1.1.1 broadens the virtualization storage support for and extends the
copy services offered by IBM's TotalStorage Virtualization Family's first
release of SAN Volume Controller, announced on June 3, 2003.
Users will find in SAN Volume Controller Version 1.1.1 new
virtualization capabilities and additional storage support designed to
help improve management of the complexity and utilization of their
storage environments.
IBM TotalStorage SAN Volume Controller Version 1.1.1 adds support for
additional storage subsystems and products -- see the support Web site
listed under Current Technical Information.
Support for IBM BladeCenter, in Optical Passthrough Mode, is now
available to further extend the SAN Volume Controller host support.
"Single path" support means that between the SAN Volume Controller and
the disk array there is a single path for data transfer as opposed to the
normal multipathing support. If that link is unavailable for any reason,
the SAN Volume Controller will lose access to data on the storage array,
but once the link is restored, the data can become available once again.
Although this level of attachment is not recommended for production data,
it can be used for dynamic data migration from this type of disk array to
another array, or for a single-path array to be used as the target for
FlashCopy data, or for non-critical data storage.
Remote Copy operations are neither recommended nor supported on single
path-attached arrays, due to the availability exposure associated with
this attachment mode.
To address overall storage system interoperability and scalability,
the Subsystem Device Driver (SDD) of SAN Volume Controller now has the
ability to coexist on a particular host with IBM FAStT RDAC (on the AIX,
and Windows platforms). New support to extend environment
interoperability is now available for Cisco MDS 9000 and for Brocade
2109-M12 SAN Fabric vendor switches.
Copy Services also have been enhanced to provide full Peer-to-Peer
Remote Copy (PPRC) function on all hosts supported by this IBM SAN Volume
Controller Storage Software release. Additionally, storage systems that
utilize full multipath attachment capabilities for SAN Volume Controller
attachment, including the storage, switch fabric, and switches newly
added to this release, are now fully supported with PPRC, removing
related restrictions of the initial release.
IBM SAN Volume Controller Storage Software Version 1.1.1 provides new
system infrastructure capabilities to promote storage resiliency in
existing SAN environments and enhanced disaster recovery capabilities
with new backup and recovery functions for SAN Volume Controller
configuration data, including the backup of such configuration data as:
mDisks, mDisk groups, vDisks, vDisks-to-hosts mapping, and FlashCopy and
PPRC copy relationships.
SAN Volume Controller Storage Software, Version 1.1.1 also includes
key Serviceability improvements to the Installation procedure, to help
simplify hardware installation.
IBM TotalStorage SAN Volume Controller V1.2.0 -- Extended Range
and Attachability
IBM TotalStorage SAN Volume Controller Storage Software V1.2.0 further
broadens the virtualization storage support for, and extends the range
of, the functions offered by the first release of SAN Volume Controller,
which was announced in Software Announcement 203-150, dated June 3, 2003,
and augmented by Software Announcement 203-274, dated October 14, 2003.
In SAN Volume Controller V1.2.0, users will find new capabilities and
additional storage support designed to help improve management of the
complexity and utilization of their storage environments.
Using virtualization technology, SAN Volume Controller V1.2.0 is
designed to provide attachment support and virtualization of a wide range
of storage controllers from IBM and other vendors.
Specifically, this release adds support for attachment of:
- EMC Clariion CX200, CX400, CX600, FC4700
- Dell/EMC Clariion CX200, CX400, CX600
- Dell/EMC FC4700
- EMC Symmetrix 8000-series models
- HDS 9530V, 9570V, 9580V
- HDS 9970V, 9980V
Additionally:
- Support for EXP100 SATA drive drawers on FAStT 600, 600T, and 900 is
added.
- Support for HP MA8000, EMA12000, and EMA16000 is upgraded to include
multipath fail-over to SAN Volume Controller.
SAN Volume Controller Storage Software V1.2.0 adds attachment and
support for the following host server operating systems (1):
- Windows 2003 Standard Edition
- Windows 2003 Enterprise Edition
- Sun Solaris 9 (64-bit only)
- VMware ESX 2.1 in single path mode with Windows 2000 Advanced Server,
Windows 2003 Enterprise Edition, and Novel Netware 6.5. Specific
configuration restrictions should be validated for these environments at:
http://www.ibm.com/storage/support/2145
SAN Volume Controller Storage Software V1.2.0 provides attachment and
support for the following fibre channel extender, to augment the
synchronous PPRC path distance capability over which SVC can be deployed:
- CNT UltraNet Edge Storage Router
SAN Volume Controller Storage Software V1.2.0 provides additional
interoperability with the IBM BladeCenter blades by supporting not only
the Optical Passthrough Module, but now, also the 2 port Fibre Channel
Switch module in the following specific configurations:
- IBM BladeCenter HS20 and HS40 features
Plan your installation now
Customers with existing SAN Volume Controller Storage Software
intallations running V1.1.0 or V1.1.1 will want to plan the transition to
V1.2.0. For transition planning guidance and options, refer to the
support Web site listed above.
Prerequisites for Installation
SAN Volume Controller Storage Software V1.2.0 for new orders is
preinstalled on IBM 2145-4F2 SAN Volume Controller Storage Engines, and
requires a co-order of this hardware.
Current SAN Volume Controller Storage Solution customers may install
V1.2.0 on existing SAN Volume Controller Storage Engine hardware,
without hardware modification.
For ordering information and a full description of the SAN
Volume Controller functions, hardware prerequisites, and
publications listing installation requirements, refer to
the SAN Volume Controller Storage
Software and Hardware Announcements dated June 3, 2003.
(1) Note: For updated support information including microcode levels
supported, connectivity support, installation guidance,
as well as current status on configuration or operational
restrictions and limitations
for SAN Volume Controller, visit the TotalStorage Support Web site at:
http://www.ibm.com/storage/support/2145
Section 508 of the U.S. Rehabilitation Act
SAN Volume Controller Storage Software is capable, as of July 25,
2003, when used in accordance with IBM's associated documentation, of
satisfying the applicable requirements of Section 508 of the
Rehabilitation Act provided that any assistive technology used with the
product properly interoperates with it.
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Technical Description
|
This program requires at least one pair of SAN Volume Controller
Storage Engines with dual Uninterruptible Power Supplies and master
console, or one IBM 2146-V1A SAN Integration Server (which integrates the
above elements) for installation.
Current support summaries, including specific software, hardware and
firmware levels supported, are maintained at:
http://www.ibm.com/storage/support/2145
SAN Volume Controller Storage Software supports connectivity with
Intel-based servers running Windows NT, or Windows 2000 Advanced Server,
or Red Hat Linux AS, and with RISC-based servers running AIX, HP-UX, or
Sun Solaris operating systems. These servers require the Subsystem
Device Driver (SDD) multipathing driver.
Current software support summaries, including specific release and
firmware levels, are maintained at:
http://www.ibm.com/storage/support/2145
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Planning Information
|
Customer Responsibilities
Planning for and provision of the power and environmental support of
the corequisite SAN Volume Controller Storage Engines and/or SAN
Integration Server is a customer responsibility.
Planning considerations for SAN Volume Controller Storage Software are
listed in the IBM TotalStorage Virtualization Family SAN Volume
Controller: Planning Guide, GA22-1052.
Limitations
This program, 5639-VC1, operates on specified storage engine hardware
only.
Additional limitations and configuration guidelines may apply, as
documented in the SAN Volume Controller Storage Software README file,
furnished publications for this product, and/or as listed under
configuration requirements and guidelines at:
http://www.ibm.com/storage/support/2145
The SAN Volume Controller includes a license for the IBM Tivoli Bonus
Pack for SAN Management or Bonus Kit for SAN Management. The license for
the IBM Tivoli Bonus Pack for SAN Management or Bonus Kit for SAN
Management applies to the enterprise acquiring the SAN Volume Controller
Storage Software and allows up to 64 switch ports to be managed.
Multiple Bonus Kit licenses (including any licenses the enterprise may
have for the predecessor to the Bonus Kit, IBM Tivoli Bonus Pack for SAN
Management) are not cumulative. These 64 ports may be on more than one
switch, but every port on a switch selected for entitlement management
must count as a port in the "up to" number, unless the entire entitlement
(all 64 ports) are allocated to a single switch which has more than 64
ports. When more than 64 switch ports are managed in an enterprise, a
separate license for the full IBM Tivoli Storage Area Network Manager
product is required.
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Publications
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For new orders, hard copies of the following publications ship with
each corequisite SAN Volume Controller Storage Engine or SAN Integration
Server.
- IBM TotalStorage Virtualization Family SAN Volume Controller:
Installation Guide (SC26-7541)
For new orders, a printable soft copy of all the downloadable IBM
TotalStorage SAN Volume Controller publications listed below, except IBM
TotalStorage Virtualization Family SAN Volume Controller: "Host
Attachment Guide" (SC26-7563), also ships with the corequisite SAN Volume
Controller Storage Engine or SAN Integration Server.
The Publications CD also contains Information Center, for topic-based
online user assistance for product and service information.
The following publications can be downloaded immediately from the IBM
TotalStorage Product Support Web site at:
http://www.ibm.com/storage/support/2145
Title Order Number
--------------------------------------- ------------
IBM TotalStorage Virtualization Family SC26-7541
SAN Volume Controller:
Installation Guide
IBM TotalStorage Virtualization Family SC26-7542
SAN Volume Controller:
Service Guide
IBM TotalStorage Virtualization Family SC26-7543
SAN Volume Controller:
Configuration Guide
IBM TotalStorage Virtualization Family SC26-7544
SAN Volume Controller:
Command-Line Interface User's Guide
IBM TotalStorage Virtualization Family GA22-1052
SAN Volume Controller: Planning Guide
IBM TotalStorage Virtualization Family: SC26-7545
SAN Volume Controller:
CIM Agent Developer's Reference
Subsystem Device Driver User's Guide SC26-7540
for IBM TotalStorage Enterprise Storage
Server and IBM TotalStorage SAN Volume
Controller
IBM TotalStorage Virtualization Family: SC26-7563
SAN Volume Controller:
Host Attachment Guide
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Security, Auditability, and Control
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The IBM TotalStorage SAN Volume Controller Storage Software user
interface uses the security features of Microsoft Windows 2000 Server
Edition, in conjunction with Web Secure Shell (SSH) and Secure Socket
Layer (SSL) protocols and WebSphere.
The customer is responsible for evaluation, selection, and
implementation of security features, administrative procedures, and
appropriate controls in application systems and communication facilities.
Trademarks
(R), (TM), * Trademark or registered trademark of International
Business Machines Corporation.
** Company, product, or service name may be a trademark or service
mark of others.
Windows is a trademark of Microsoft Corporation.
© IBM Corporation 2005.
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