SAN Volume Controller Software V4.2.1 further enhances
the advanced copy functions of SAN Volume Controller Software
V4.2.0 by adding:
Incremental FlashCopy
Cascaded FlashCopy
Dynamically configurable replication services space
Capability to address storage up to eight petabytes
Incremental FlashCopy provides the
ability to copy only the portions of the source
virtual disk (vdisk) that have been updated at either the
source or target, instead of copying the whole vdisk.
This capability enables the FlashCopy function to complete more
quickly, thus reducing the impact of using FlashCopy.
Cascaded FlashCopy
is the ability to use a target vdisk
of a FlashCopy mapping as the source vdisk of another FlashCopy mapping.
The total number of targets from the original
source or based on intermediate target sources, must be 16 or less.
Dynamically configurable replication services space
provides the
ability to configure up to 256 TB of address space per I/O group
as needed, allocatable across FlashCopy, Metro Mirror,
and Global Mirror in variable, user-customizable proportions.
Increased storage addressing provides
support for larger virtual storage configurations by extending
the storage addressing capability of SAN Volume Controller from two
petabytes to eight petabytes per cluster.
Volume management options are improved in
SAN Volume Controller Software V4.2.1 by the new
capability to assign or change the preferred
node, when moving vdisks among I/O groups while performing
I/O group rebalancing.
Managed disk (mdisk) test before add to MDisk Group
is a built-in test allows
an mdisk to be added that is both readable and writable;
this reduces the likelihood of problems when the mdisk is configured.
Interoperability enhancements include:
Host:
IBM AIX V6.1
Storage controllers:
HP StorageWorks 4100/6100/8100 Enterprise Virtual Arrays
SAN Volume Controller Software V4.2.1 is compliant with the
SMI-S 1.2 standard.
Incremental FlashCopy
Incremental FlashCopy provides the ability to optimize a background copy
process to copy only the parts of the source vdisk
which have been
updated (at either the source or target) since the last
time a FlashCopy was
taken.
Note: Incremental FlashCopy
requires the same amount of storage capacity as a regular
FlashCopy.
Incremental FlashCopy:
Is a create-time option (not switchable).
Can be used in conjunction with Multiple Target FlashCopy mappings.
May share same source vdisk with non-incremental FlashCopy.
Up to 256 TB of replication space per I/O Group
can be allocated to Incremental
FlashCopy, only if no other replication service from the same I/O group
requires concurrent allocation. Refer to the text in the
User configurable replication services space up to 256 TB
per I/O Group
section below.
For further operational conditions and vdisk mapping options,
refer to the currently updated user publications:
IBM System Storage SAN Volume Controller
Software Installation and Configuration
Guide, SC23-6628.
IBM System Storage SAN Volume Controller
Command-Line Interface Guide, SC26-7903
Cascaded FlashCopy
SAN Volume Controller Software
V4.2.1 implements the ability to cascade FlashCopy
mappings; that is,
the ability to use a target vdisk
of a FlashCopy mapping as the source vdisk of another FlashCopy mapping.
SAN Volume Controller software prior to V4.2.1
does not allow a disk which is a source in one FlashCopy
mapping to be a target disk in another one. If users wish to copy a
target disk, they must wait for the mapping to be copy-complete. At this
point, they must destroy the mapping, before creating and triggering the
new one.
With SAN Volume Controller Software V4.2.1, users
can define and trigger "Map 2,"
even while "Map 1" is still not copy-complete.
The mappings could be incremental or
non-incremental mappings. An important restriction is that "number of
targets defined from a given source" + "number of targets defined from
any of these targets" must always be less than or equal to 16.
User configurable replication services space up to 256 TB
per I/O Group
SAN Volume Controller Software V4.2.0 provided the ability
to statically divide up to 80 TB of copy services per I/O group
between FlashCopy and Metro/Global Mirror relationships.
SAN Volume Controller Software V4.2.1 adds the ability for the user
to dynamically configure up to 256 TB of copy services address space
per I/O Group, allocated between FlashCopy (including incremental
FlashCopy), Metro Mirror, and Global
Mirror relationships in user-chosen proportions.
This new facility allows for the option to allocate cache memory
address space when needed to achieve copy services requirements.
The exact amount of copy services space available to users will
depend upon the copy services relationships used and the resulting
copy services space allocated to each vdisk.
Increased storage addressing
In SAN Volume Controller Software V4.2.1, the storage addressing
capability has been increased from two
petabytes to eight petabytes per cluster.
This capability is based on an increased extent size (up to 2 GB),
and applies regardless of the number of nodes in the cluster.
Mdisk and vdisk relation and use are unaffected by this increase.
Volume management
SAN Volume Controller Software V4.2.1 introduces the
ability to assign
or change preferred nodes upon vdisk move. Prior to V4.2.1, SAN Volume
Controller software supported the
specification of a preferred node only at
vdisk creation time. It is often desirable to assign preferred nodes
during rebalancing operations.
Specification of preferred nodes during vdisk move operations
requires halting I/O to the affected vdisks, but can result
in restoration of better I/O balance following a change in workload
pattern or in conjunction with post-recovery rebalancing.
Mdisk test before add to mdisk group
This built-in test allows
an mdisk to be added that is both readable and writable,
and thus reduces the likelihood of problems when the mdisk is added.
Interoperability enhancements in V4.2.1 include:
Host:
Aix 6.1
Controller:
HP StorageWorks 4100/6100/8100 Enterprise Virtual Arrays (EVA)
Master Console options
Beginning with the IBM System Storage Productivity Center Basic Edition
V3.3.1,
IBM System Storage Productivity Center will provide an alternative,
preloaded, delivery option for
the SVC GUI and CIM Agent (CIMOM) components
for IBM System Storage SAN Volume Controller V4.2.1.
This alternative to the SVC Master Console may, in some cases, enable
a reduction of the total number of servers
required in an installation to manage the storage environment.
To explore this option,
refer to the current System Storage Productivity Center announcements
listed in the Reference information section,
and consult with your IBM System Storage representative.
SMI-S 1.2 compliance
SAN Volume Controller Software V4.2.1 is compliant with the
Storage Networking Industry Association (SNIA)
Storage Management Initiative Specification (SMI-S) 1.2,
with interoperable support for
volume protection, copy consistency management, and replication,
among other elements of this specification.
IBM System Storage SAN Volume Controller Software V4 is designed to
help address the complexities and costs of managing SAN-based storage.
It is designed so that it can be added to existing SANs and deliver its
benefits
to an increasingly broad customer environment. The copy services
enhancements included in V4.2.1 further increase customer value by
providing more flexibility to customers in managing their environments;
these copy services also provide
important new function that helps enable FlashCopy to be used more widely
and with less impact to applications. The scalability enhancements in
V4.2.1
enable SVC to manage even larger configurations, which helps larger
customers to simplify their environments even more with SVC.
For SAN Volume Controller V4 ordering information,
refer to
Programming Announcement letter ZP06-0241
dated May 23, 2006.
For SAN Volume Controller Software
Advanced Copy function enhancements and interoperability added in
V4.2.0,
refer to
Programming Announcement letter ZP07-0252
dated May 22, 2007.
For the IBM System Storage SVC Master Console Memory Upgrade
availability announcement,
refer to
Product Announcement letter ZG07-0742
dated October 23, 2007.
For implementation of the
Master Console for SAN Volume Controller on the IBM System Storage
Productivity Center solution, refer to the following:
For IBM System Storage Productivity Center, Consolidated Device
Management solution overview,
refer to
Marketing Announcement letter ZA07-0200
dated October 23, 2007.
For IBM System Storage Productivity Center hardware
(Machine type 2805),
refer to
Product Announcement letter ZG07-0686
dated October 23, 2007.
For IBM TotalStorage Productivity Center Basic Edition V3.3.1
pre-installed on IBM System Storage Productivity Center,
refer to
Programming Announcement letter ZP07-0448
dated October 23, 2007.
Current SAN Volume Controller publications will be
updated to reflect the content of this announcement.
Publication order numbers as originally announced are unaffected.
Updated English publications will be available for download
from the SAN Volume Controller Support Web site and from the
Infocenter Web site, by November 9, 2007.
Updated Translated publications will be available from the SAN
Volume Controller Support Web site and from the Infocenter publications
Web site by January 21, 2008.
For publication order numbers and titles,
refer to
Programming Announcement letter ZP07-0252
dated May 22, 2007.
You can use the following options to order or download additional copies:
Visit the IBM Publications Center Web site
http://www.ibm.com/shop/publications/order
Visit the IBM product support Web site
http://www.ibm.com/storage/support/2145
Call the Publications Support Group at 800-879-2755, and select option 1.
Hardware and software requirements
are unchanged from the SAN Volume Controller Software
V4.2 announcement.
For information regarding implementation of the SAN Volume Controller
Master Console on the IBM System Storage Productivity Center solution,
refer to announcements listed in the Reference information
section.
Note for current customers:
The Microsoft Windows platform
provision for SAN Volume Controller Master Console installation is a
customer responsibility.
Further, you must obtain Microsoft Windows license and
code upgrades directly from Microsoft. IBM cannot supply Windows
platform
upgrades for the SAN Volume Controller Master Console platform.
It is recommended that both the Windows
platform upgrade to Windows 2003 R2 and the installation of current
Master Console code be completed by customers,
prior to scheduling upgrade to SAN Volume Controller Software V4.
For further information and current updates, refer to the SAN Volume
Controller
Support Web site:
Ordering features information are unaffected by this announcement.
The announced functions are included in the base SAN Volume Controller
Software V4.2.1 code. Use existing authorization features to order.
For feature and part number ordering information,
refer to
Programming Announcement letter ZP06-0241
dated May 23, 2006.
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Offerings include financing for IT acquisition, including hardware,
software, and services, from both IBM and other manufacturers or
vendors. Offerings (for all customer segments: small, medium, and
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Contact your local IBM Global Financing organization or visit
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to qualified commercial and government customers. Rates are based on a
customer's credit rating, financing terms, offering type, equipment type,
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Rates and offerings are subject to change, extension, or withdrawal
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which is available from the same IBM announcement letters database.
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