IBM System Storage SAN Volume Controller 6.2.0 Configuration Limits and Restrictions

DS4000 Maintenance

SAN Volume Controller supports concurrent ESM firmware upgrades for those DS4000 models listed as such on the Supported Hardware List when they are running either 06.23.05.00 or later controller firmware. However, controllers running firmware levels earlier than 06.23.05.00 will not be supported for concurrent ESM upgrades. Customers in this situation, who wish to gain support for concurrent ESM upgrades, will need to first upgrade the DS4000 controller firmware level to 06.23.05.00. This action is a controller firmware upgrade, not an ESM upgrade and concurrent controller firmware upgrades are already supported in conjunction with SAN Volume Controller. Once the controller firmware is at 06.23.05.00 or later the ESM firmware can be upgraded concurrently.

Note: The DS4000 ESM firmware upgrade must be done on one disk expansion enclosure at a time. A 10 minute delay from when one enclosure is upgraded to the start of the upgrade of another enclosure is required. Confirm via the Storage Manager applications "Recovery Guru" that the DS4000 status is in an optimal state before upgrading the next enclosure. If it is not, then do not continue ESM firmware upgrades until the problem is resolved.

Host Limitations

Windows NTP server

The Linux NTP client used by SAN Volume Controller may not always function correctly with Windows W32Time NTP Server

Windows SAN Boot Clusters (MSCS):

It is possible to SAN Boot a Microsoft Cluster subject to the following restrictions imposed by Microsoft:

• Windows 2000 Server clusters require that the boot disk be on a different storage bus to the cluster server disks.
• On Windows 2003, clustered disks and boot disks can be presented on the same storage bus, but ONLY if the Storport driver is being used.

These restrictions and more are described in the Microsoft White Paper: "Microsoft Windows Clustering: Storage Area Networks".

We have not tested, and therefore do not support, modifying the registry key as suggested on page 28 (which would allow boot disks and clustered disks on the same storage bus on Windows 2003 without the Storport driver).


Oracle

Oracle Version and OS	Restrictions that apply:
Oracle RAC 10g on Windows:	1
Oracle RAC 10g on AIX:	1, 2
Oracle RAC 11g on AIX:	2
Oracle RAC 10g on HP-UX11.31:	1, 2
Oracle RAC 11g on HP-UX11.31:	1, 2
Oracle RAC 10g on HP-UX11.23:	1, 2
Oracle RAC 11g on HP-UX11.23:	1, 2
Oracle RAC 10g on Linux Host:	1, 3

Restriction 1: ASM cannot recognise the size change of the disk when SVC disk is resized unless the disk is removed from ASM and included again.

Restriction 2: After an ASM disk group has successfully dropped a disk, the disk cannot be deleted from the OS. The workaround to the OS restriction is to bring down the ASM instance, delete the disk from the OS, and bring up the ASM instance again.

Restriction 3: For RHEL4 set Oracle Clusterware 'misscount' parameter to a bigger one to allow SDD to do path failover first. The default miscount setting 60s is too short for SDD. We recommend to set it 90s or 120s. Command to use: crsctl set css misscount 90



Maximum Configurations

Configuration limits for SAN Volume Controller 6.2.0:

Property	Maximum Number	Comments
System (Cluster) Properties
Nodes per system (cluster)	8	Arranged as four I/O groups
Nodes per fabric	64	Maximum number of SVC and V7000 nodes that can be present on the same Fibre Channel fabric, with visibility of each other
I/O groups per system	4	Each containing two nodes
Fabrics per system	4	The number of counterpart Fibre Channel SANs which are supported
Inter-cluster partnerships per system	3	A system may partnered with up to three remote systems. No more than four systems may be in the same connected set
Node Properties
Logins per node Fibre Channel port	512	Includes logins from server HBAs, disk controller ports, node ports within the same system and node ports from remote systems
iSCSI sessions per node	256	512 in IP failover mode (when partner node is unavailable)
Managed Disk Properties
Managed disks (MDisks) per system	4096	The maximum number of logical units which can be managed by a cluster. This number includes external MDisks which have not been configured into storage pools (managed disk groups)
Managed disks per storage pool (managed disk group)	128
Storage pools per system	128
Managed disk extent size	8192 MB
Capacity for an individual internal managed disk (array)	-	No limit is imposed beyond the maximum number of drives per array limits.
Capacity for an individual external managed disk	1 PB	Note: External managed disks larger than 2 TB are only supported for certain types of storage systems. Refer to the supported hardware matrix for further details.
Total storage capacity manageable per system	32 PB	Maximum requires an extent size of 8192 MB to be used This limit represents the per system maximum of 2^22 extents.
Volume (Virtual Disk) Properties
Volumes (VDisks) per system	8192	Maximum requires an 8-node cluster; refer to the volumes per I/O group limit below
Volumes per I/O group	2048
Volumes per storage pool	-	No limit is imposed beyond the volumes per system limit
Fully-allocated volume capacity	256 TB	Maximum size for an individual fully-allocated volume
Thin-provisioned (space-efficient) volume capacity	256 TB	Maximum size for an individual thin-provisioned volume
Host mappings per system	20,000	See also - volume mappings per host object below
Mirrored Volume (Virtual Disk) Properties
Copies per volume	2
Volume copies per system	8192	The maximum number of volumes cannot all have the maximum number of copies
Total mirrored volume capacity per I/O group	1024 TB
Generic Host Properties
Host objects (IDs) per system	1024	A host object may contain both Fibre Channel ports and iSCSI names
Host objects (IDs) per I/O group	256	Refer to the additional Fibre Channel and iSCSI host limits below
Volume mappings per host object	512
Total Fibre Channel ports and iSCSI names per system	2048
Total Fibre Channel ports and iSCSI names per I/O group	512
Total Fibre Channel ports and iSCSI names per host object	512
Fibre Channel Host Properties
Fibre Channel hosts per system	1024 - Cisco, Brocade and McDATA fabrics 256 - QLogic fabrics	See also - Fibre Channel hosts per I/O group below
Fibre Channel host ports per system	2048 - Cisco, McDATA and Brocade fabrics 512 - QLogic fabrics
Fibre Channel hosts per I/O group	256 - Cisco, McDATA and Brocade fabrics 64 - QLogic fabrics
Fibre Channel host ports per I/O group	512 - Cisco, McDATA and Brocade fabrics 128 - QLogic fabrics
Fibre Channel hosts ports per host object (ID)	512
iSCSI Host Properties
iSCSI hosts per system	1024	See also - iSCSI hosts per I/O group below
iSCSI hosts per I/O group	256
iSCSI names per host object	256
iSCSI names per I/O group	256
Copy Services Properties
Remote Copy (Metro Mirror and Global Mirror) relationships per system	8192	This can be any mix of Metro Mirror and Global Mirror relationships. Maximum requires an 8-node cluster (volumes per I/O group limit applies)
Remote Copy relationships per consistency group	-	No limit is imposed beyond the Remote Copy relationships per system limit
Remote Copy consistency groups per system	256
Total Metro Mirror and Global Mirror volume capacity per I/O group	1024 TB	This limit is the total capacity for all master and auxiliary volumes in the I/O group.
FlashCopy mappings per system	4096
FlashCopy targets per source	256
FlashCopy mappings per consistency group	512
FlashCopy consistency groups per system	127
Total FlashCopy volume capacity per I/O group	1024 TB
Internal Storage System Properties
Drives per 2145-CF8 node	4
Drives per 2145-CG8 node	4
Min-Max member drives per RAID-0 array	1-4	All drives in a RAID-0 array must be located in the same node
Min-Max member drives per RAID-1 array	2-2	The pair of drives must contain one drive from one node in the I/O group and one drive from the other node in the same I/O group
Min-Max member drives per RAID-10 array	2-8	The drives are specified as a sequence of drive pairs. Each pair of drives must contain one drive from a node in the I/O group and a drive from the other node in the same I/O group
Hot spare drives	-	No limit is imposed
External Storage System Properties
Storage system WWNNs per system (cluster)	1024
Storage system WWPNs per system (cluster)	1024
WWNNs per storage system	16
WWPNs per WWNN	16
LUNs (managed disks) per storage system	-	No limit is imposed beyond the managed disks per system (cluster) limit
System and User Management Properties
User accounts per system	400	Includes the default user accounts
User groups per system	256	Includes the default user groups
Authentication servers per system	1
NTP servers per system	1
iSNS servers per system	1
Concurrent open SSH sessions per system	10
Event Notification Properties
SNMP servers per system	6
Syslog servers per system	6
Email (SMTP) servers per system	6	Email servers are used in turn until the email is successfully sent
Email users (recipients) per system	12