IBM Support

V8.5.4.x Configuration Limits and Restrictions for IBM FlashSystem 50x5 and 5200

Preventive Service Planning


Abstract

This document lists the configuration limits and restrictions specific to IBM FlashSystem 50x5 and 5200 software version 8.5.4.x.

Content

Only FlashSystem 50x5 or 5200 systems can be upgraded to 8.5.x.x software versions.

The use of WAN optimization devices such as Riverbed is not supported in native Ethernet IP partnership configurations containing FlashSystem 50x5 or 5200 systems.

VASA Provider

The embedded VASA Provider feature is not supported on FlashSystem 5200 systems configured with 32 GB memory. In a FlashSystem 5200, a minimum of 64 GB memory must be installed in each node before the embedded VASA Provider is accessible.

Safeguarded Copy

FlashSystem 5200 systems support Safeguarded Copy.

The following restrictions apply for Safeguarded Copy:

  1. Mirrored volumes cannot be safeguarded. Stretched cluster is not supported
  2. Mirroring of existing safeguarded source volumes is supported for migration purposes only
  3. HyperSwap volumes are supported. However, recovery requires that they be converted to regular volumes before use
  4. Pre-defined schedules are designed to avoid running out of FlashCopy maps in a single graph and keep within the supported volumes count. It is possible, using the CLI, to create policies that can, potentially, breach those limits. Caution must be exercised
  5. The GUI does not support creating user-defined policies but can display any created that use the CLI.
  6. The source volume cannot be in an ownership group
  7. The source volume cannot be used with Transparent Cloud Tiering (TCT).

Volume Mobility

The following restrictions apply for Volume Mobility (nondisruptive volume move between systems):

  1. No 3-site support
  2. Not intended to be a DR or HA solution
  3. No support for consistency groups, change volumes, or expanding volumes
  4. Reduced host interoperability support. Only the following host operating systems are supported:
    • RHEL
    • SLES
    • ESXi
    • Solaris
    • HP-UX
    • AIX
  5. SCSI only. Fibre Channel and iSCSI supported. NVMe not supported
  6. No SCSI persistent reservations or Offloaded Data Transfer (ODX).

Data Reduction Pools

The following restrictions apply for Data Reduction Pools (DRP):

  1. VMware vSphere Virtual Volumes (vVols) are not supported in a DRP
  2. A volume in a DRP cannot be shrunk
  3. No volume can move between I/O groups when the volume is a DRP (use FlashCopy or Metro Mirror / Global Mirror instead).
  4. No split of a volume mirror to copy in a different I/O group
  5. Real/used/free/free/tier capacity is not reported per volume - only per pool.

RAID and Distributed RAID

FlashSystem 5015, 5035 and 5200 systems do not support traditional RAID arrays.

FlashSystem 5015, 5035 and 5200 cannot create new DRAID5 arrays with more than 8 member drives (existing DRAID5 arrays with more than 8 members can be supported). Expansion beyond 8 member drives is also supported for new or existing DRAID-5 arrays.

DRAID Strip Size

For candidate drives with a capacity greater than 4 TB, a strip size of 128 cannot be specified for either RAID-5 or RAID-6 DRAID arrays. These drives must have a strip size of 256.

FlashSystem 5015, 5035 and 5200 systems do not support a strip size of 128 for any drive capacity.

Nondisruptive Volume Move (NDVM)

The following Fibre Channel attached host types are supported for nondisruptively moving a volume between I/O groups (control enclosures):

Host Operating System Host Multipathing Host Clustering Notes
AIX 7.2 AIXPCM Nondisruptive volume move can result in the same volume being mapped to different hosts in the same host cluster by using different SCSI IDs. If the host cluster cannot tolerate this configuration, then nondisruptive volume move cannot be used. SAN boot is supported
NPIV is supported
Microsoft Windows 2019 MSDSM Hyper-V Failover Cluster SAN boot is supported
Microsoft Windows 2016 MSDSM Hyper-V Failover Cluster SAN Boot is supported
Red Hat 8 Native
The original paths might need to be manually removed on the host before removing access to the old I/O group
SLES 15 Native The original paths might need to be manually removed on the host before removing access to the old I/O group
VMware 6.7 Native VAAI is supported
VMware 6.5 Native VAAI is supported
Solaris 11.3 SPARC MPXIO SAN boot is supported

Note: For all other host types, I/O needs to be quiesced before moving a volume.

When moving a volume that is mapped to a host cluster, it is required to rescan disk paths on all host cluster nodes to ensure the new paths are detected before removing access from the original I/O group.

Clustered Systems

A system requires native Fibre Channel SAN or alternatively 16Gbps / 32Gbps Direct Attach Fibre Channel connectivity for communication between all nodes in the local cluster. Clustering can also be accomplished with 25Gbps Ethernet, for standard topologies.

Partnerships between systems for Metro Mirror or Global Mirror replication can be used with both Fibre Channel and native Ethernet connectivity. Distances greater than 300 meters are supported by using an FCIP link or Fibre Channel between source and target.

All systems within a cluster must be using the same version of FlashSystem 5200 software.

Model Clustering over Fibre Channel Clustering over 25 Gb Ethernet HyperSwap over Fibre Channel HyperSwap over Ethernet (25 Gb only) Metro / Global Mirror replication over Fibre Channel Metro / Global Mirror replication over Ethernet (10 Gb or 25 Gb)
FS5015 Not supported Not supported Not supported Not supported Yes
FS5035 Yes up to 2 I/O groups Not supported Yes up to 2 I/O groups Not supported Yes
FS5200 Yes up to 4 I/O groups Yes up to 4 I/O groups Yes up to 4 I/O groups Yes up to 4 I/O groups Yes Yes

Transparent Cloud Tiering

Transparent cloud tiering, available on FS5200 systems only, is defined by configuration limitations and rules. See the IBM Documentation Transparent Cloud Tiering maximum limits page for details.

The following restrictions apply for Transparent Cloud Tiering:

  1. When a cloud account is created, it must continue to use the same encryption type, throughout the life of the data in that cloud account - even if the cloud account object is removed and remade on the system, the encryption type for that cloud account cannot be changed while back up data for that system exists in the cloud provider.
  2. Performing rekey operations on a system with an encryption-enabled cloud account, perform the commit operation immediately after the prepare operation. Remember to retain the previous system master key (on USB or in Key server) as this key can still be needed to retrieve your cloud backup data if performing a T4 recovery or an import.
  3. Avoid the use of the 'Restore_uid' option when backup is imported to a new cluster.
  4. Import of Transparent Cloud Tiering data is only supported from systems whose backup data was created at v7.8.0.1.

The following AWS regions are supported by this code-level:

  • us-east-1
  • us-west-1
  • us-west-2
  • ca-central-1
  • eu-west-1
  • eu-west-2
  • eu-west-3
  • eu-central-1
  • sa-east-1
  • ap-southeast-1
  • ap-southeast-2
  • ap-south-1
  • ap-northeast-1
  • ap-northeast-2
Snapshots and TCT
TCT cloud snapshots are supported with the system's new FlashCopy® management model based on snapshot function.
However, cloud snapshots cannot co-exist with the user-owned legacy FlashCopy mappings.
For more information, refer to the following links:-
Snapshot function

Encryption and TCT

There is a small possibility that, on a system that uses both Encryption and Transparent Cloud Tiering, the system can enter a state where an encryption rekey operation is stuck in 'prepared' or 'prepare_failed' state, and a cloud account is stuck in 'offline' state. The user is unable to cancel or commit the encryption rekey because the cloud account is offline. The user is unable to remove the cloud account because an encryption rekey is in progress.
The system can be recovered from this state by using a T4 Recovery procedure.
It is also possible that SAS-attached storage arrays go offline.

The 2 scenarios identify where this might happen:

Scenario A

  1. Using USB encryption and Cloud.
  2. A new USB key is prepared by using 'chencryption -usb newkey -key prepare'.
  3. The new presumptive key is deleted from all USB sticks before the new key is committed.
  4. All nodes in the system are rebooted.
  5. The cloud account is offline as it cannot get the presumptive key. The cloud account cannot be removed, and the encryption rekey cannot be completed or cancelled. The system remains stuck in these cloud and encryption states.
  6. Any SAS-attached arrays are offline and locked.
  7. The system can be restored by T4 to a previous config backup.
 

Scenario B

  1. Using key server encryption and Cloud.
  2. A new key server key is prepared by using 'chencryption -keyserver newkey -key prepare'.
  3. The new presumptive key is deleted from the key server before the new key is committed.
  4. All nodes in the system are rebooted.
  5. The cloud account is offline as it cannot get the presumptive key. The cloud account cannot be removed, and the encryption rekey cannot be completed or cancelled. The system remains stuck in these cloud and encryption states.
  6. SAS-attached arrays are not affected.
  7. The system can be restored by T4 to a previous config backup.

NPIV (N_Port ID Virtualization)

The following recommendations and restrictions can be followed if implementing NPIV:

FCoE is not supported by NPIV.

Operating systems not currently supported for use with NPIV:

  • HPUX 11iV2
  • Veritas DMP multipathing on Windows with RAID-5 volumes in VxVM
  • IBMi in Direct attach

Other Operating Systems

Other operating Systems might also experience the same issue if modifying the NPIV state from "Transitional" to "Disabled", in which case the operating system-specific rescan command can be used.

Fabric Attachment

NPIV mode is only supported when used with Brocade or Cisco Fibre Channel SAN switches that are NPIV capable.

HyperSwap

Configure your host multipath driver to use an ALUA-based path policy.

Due to the requirement for multiple access I/O groups, SAS attached host types are not supported by HyperSwap volumes.

A volume configured with multiple access I/O groups, on a system in the storage layer, cannot be virtualized by a system in the replication layer.  This restriction prevents a HyperSwap volume on one system being virtualized by another.

AIX Live Partition Mobility (LPM)
AIX LPM is supported by the HyperSwap function and AIX 7.x.

Direct Attachment

IBM System Storage DS8000 series is not supported by direct-attached systems.

SAN boot on Windows 2019 (Qlogic HBA) is not supported by 32 GB direct-attached systems.

16 Gbps Fibre Channel Node Connection

Refer to the IBM System Storage Inter-operation Center (SSIC) for supported 16 Gbps Fibre Channel configurations supported by 16 Gbps node hardware.

Note 16 Gbps Node hardware is supported when connected to Brocade and Cisco 8 Gbps or 16 Gbps fabrics only.

Direct connections to 2 Gbps or 4 Gbps SAN or direct host attachment to 2 Gbps or 4 Gbps ports is not supported.

Other configured switches that are not directly connected to the 16 Gbps Node hardware can be any supported fabric switch as currently listed in the SSIC.

25 Gbps Ethernet Canister Connection

For 50xx Products, one optional 2-port 25Gbps Ethernet adapter is supported in each node canister for iSCSI communication with iSCSI capable Ethernet ports in hosts via Ethernet switches.

For 5200 Products, two optional 2-port 25Gbps Ethernet adapters are supported in each node canister for iSCSI communication with iSCSI capable Ethernet ports in hosts via Ethernet switches.

These 2-port 25 Gbps Ethernet adapters do not support FCoE.

There are two types of 25 Gbps Ethernet adapter Feature supported:

1) RDMA over Converged Ethernet (RoCE)

2) Internet Wide-area RDMA Protocol (iWARP)

Either works for standard iSCSI communications with hosts, for example, by not using Remote Direct Memory Access (RDMA). RDMA can be used on the adapters for clustering purpose over iWARP.

When use of RDMA with a 25 Gbps Ethernet adapter becomes possible then RDMA links work between RoCE ports or between iWARP ports (that is, from a RoCE node canister port to a RoCE port on a host or from an iWARP node canister port to an iWARP port on a host).

For Ethernet switches and adapters supported in hosts, visit the SSIC

Example of an RoCE adapter for use in a host

Example of an iWARP adapter for use in a host

IP Partnership

IP partnerships are supported on any of the available Ethernet ports. Using an Ethernet switch to convert a 25 Gb to a 1 Gb IP partnership, or a 10 Gb to a 1 Gb IP partnership is not supported. Therefore, the IP infrastructure on both partnership sites must match. Bandwidth limiting on IP partnerships between both sites is supported.

VMware vSphere Virtual Volumes (vVols)

The maximum number of virtual machines on a single VMware ESXi host in a Storwize / vVol storage configuration is limited to 680.

The use of VMware vSphere Virtual Volumes (vVols) on a system that is configured for HyperSwap is not currently supported by SVC / Storwize.

Host Limitations

SAN BOOT function on AIX 7.2 TL5

SAN BOOT is not supported for AIX 7.2 TL5 when connected by using the NVME/FC protocol.

RDM Volumes attached to guests in VMware 7.0
Using RDM (raw device mapping) volumes attached to any guests, with the RoCE iSER protocol, results in pathing issues or inability to boot the guest.

N2225/N2226 SAS HBA
VMware 6.7 (Guest O/S SLES12SP4) connected by SAS N2225/N2226 host adapters are not supported.

Lenovo 430-16e/8e SAS HBA
VMware 6.7 and 6.5 (Guest O/S SLES12SP4) connected by SAS Lenovo 430-16e/8e host adapters are not supported.
Windows 2019 and 2016 connected by SAS Lenovo 430-16e/8e host adapters are not supported.

Windows 2016 HyperV
RHEL v7.1 guests on Windows 2016 HyperV, with Virtual Fibre Channel, are not supported.

iSER
Operating systems not currently supported for use with iSER:

  • Windows 2012 R2 with Mellanox ConnectX-4 Lx EN adapter
  • Windows 2016 with Mellanox ConnectX-4 Lx EN adapters

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

Fabric Limitation

Only one FCF (Fibre Channel Forwarder) switch per fabric is supported.

Storage connected directly to a Cisco Fabric Extender (FEX) is not supported.

Priority Flow Control for iSCSI / iSER

Priority Flow Control for iSCSI / iSER is supported on Emulex and Chelsio adapters (SVC supported) with all DCBX enabled switches.

Policy-based Replication
FlashSystem 5200 systems support Policy-based replication.  A minimum of 128 GB memory must be installed in each node canister.
The following configuration limits and restrictions apply to policy-based replication:
  1. The name of a volume group cannot be changed while a replication policy is assigned.
  2. The name of a volume cannot be changed while the volume is in a volume group with a replication policy assigned.
  3. Ownership groups are not supported by policy-based replication.
  4. Policy-based replication is not supported on HyperSwap topology systems.
  5. Policy-based replication cannot be used with volumes that are:
  •    Image mode
  •    HyperSwap
  •    Part of a remote-copy relationship
  •    Configured to use Transparent Cloud Tiering (TCT)
  •    VMware vSphere Virtual Volumes (vVols)
The following actions cannot be performed on a volume while the volume is in a volume group with a replication policy assigned:
  1. Resize (expand or shrink)
  2. Migrate to image mode, or add an image mode copy
  3. Move to a different I/O group

Maximum Configurations

Configuration limits for FlashSystem 5015, 5035, 5200:

Property
Hardware Type
Maximum Number
 Comments
System (Cluster) Properties
I/O groups / Control Enclosures per system (cluster) FS5015 1 Each control enclosure contains two node canisters
FS5035 2
FS5200 4
Active nodes per system FS5015 2
FS5035 4 Arranged as two I/O groups
FS5200 8 Arranged as four I/O groups
Nodes per fabric
64
 Maximum number of Spectrum Virtualize nodes that can be present on the same Fibre Channel fabric, with visibility of each other
Fabrics per system
6
 The number of counterpart Fibre Channel SANs that are supported
- Up to 4 fabrics that use native Fibre Channel ports
Inter-cluster partnerships per system
3
 A system can be partnered with up to three remote systems. No more than four systems can be in the same connected set
IP Quorum devices per system
5
Data encryption keys per system
1,024
Key servers per system 4
Node Properties 
Logins per node Fibre Channel WWPN
512
 Includes logins from server HBAs, disk controller ports, node ports within the same system and node ports from remote systems
Portset objects per system 72 FC + Ethernet
IP address objects per system 2,048 Includes duplicated IP addresses
IP address objects per node 256
IP addresses per port 64
When node failover occurs, Ethernet ports that have the same ID are configured with the IP addresses of the partner. Hence there can be a maximum of 128 IP addresses configured per Ethernet port during failover.
For Emulex ports, there can be a maximum of 3 unique VLANs per port and a maximum of 32 IP addresses per port.
For Mellanox iSER connectivity, there can be a maximum of 31 VLANs per port and a maximum of 31 IP addresses per port with VLAN.
Routable IP addresses per port 1
iSCSI sessions per node
1,024
 2048 in IP failover mode (when partner node is unavailable).
This limit includes both iSCSI Host Attach AND iSCSI Initiator sessions
iSER sessions per node FS5200 256
iSCSI + iSER sessions per node FS5200 1,088
Managed Disk Properties 
Managed disks (MDisks) per system
4,096
 The maximum number of logical units that can be managed by a system, including internal arrays.

Internal distributed arrays consume 16 logical units.

This number also includes external MDisks that are not configured into storage pools (managed disk groups)
Managed disks per storage pool (managed disk group)
128
Storage pools per system
1,024
Parent pools per system
128
Child pools per system
1,023
Managed disk extent size
8,192 MB
Capacity for an individual internal managed disk (array)
-
 No limit is imposed beyond the maximum number of drives per array limits.
Maximum size depends on the extent size of the Storage Pool.
Comparison Table: Maximum Volume, MDisk, and System capacity for each extent size.
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.
Maximum size depends on the extent size of the Storage Pool.
Comparison Table: Maximum Volume, MDisk, and System capacity for each extent size.
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.

Comparison Table: Maximum Volume, MDisk, and System capacity for each extent size.
Maximum Provisioning policies 32
Data Reduction Pool Properties
Data Reduction Pools per system
4
MDisks per Data Reduction Pool
128
Volume copies per Data Reduction Pool FS5015 4,096
FS5035
FS5200
 8,192
Extents per I/O group per Data Reduction Pool
524,288 (512K)
Volume (Virtual Disk) Properties 
Basic Volumes per system FS5015 2,048 Each Basic Volume uses 1 VDisk, each with one copy.
FS5035
FS5200
 8,192
Volume copies in host mappable volumes per system FS5015 4,096
FS5035
FS5200
 8,192
Stretched volumes per system N/A
HyperSwap volumes per system FS5035 1,250 Each HyperSwap volume uses 4 VDisks, each with one copy, 1 active-active remote copy relationship, and 4 FlashCopy mappings.
FS5200 2,000
Volume copies per volume 2
Total mirrored volume capacity per I/O group 1 PB
Volumes per I/O group (volumes per caching I/O group) - No limit exists beyond the volumes per system limit
Volume Groups per system
FS5015
FS5035
 0
FS5200 1,024
Volumes per volume group
FS5015
FS5035
 N/A
FS5200 512
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. 

Maximum size depends on the extent size of the Storage Pool.
Comparison Table: Maximum Volume, MDisk, and System capacity for each extent size.
Thin-provisioned (space-efficient) per-volume capacity for volumes in regular and data reduction pools 256 TB Maximum size for an individual thin-provisioned volume.

Maximum size depends on the extent size of the Storage Pool.
Comparison Table: Maximum Volume, MDisk, and System capacity for each extent size.
Host mappings per system 20,000 See also - volume mappings per host object
Host Properties 
Host objects (IDs) per system FS5015 256
FS5035 512
FS5200 1,024
Host objects (IDs) per I/O group
256
Volume mappings per host object 512
Unique IP addresses per port 64
IP addresses per node per portset Host 4
Remote Copy 1
Storage Number of Ethernet Ports on node
FC ports per portset 4
FC Host objects per portset Same as the maximum number of hosts supported on that platform
Host Cluster Properties 
Host clusters per system
512
Hosts in a host cluster
128
Fibre Channel Host Properties
Fibre Channel hosts per system FS5015 256
FS5035 512
FS5200 1,024
Fibre Channel host ports per system FS5015 2,048
FS5035 4,096
FS5200 8,192
Fibre Channel hosts per I/O group
256
Fibre Channel host ports per I/O group
2,048
NPIV Direct Attach Logins per Fibre Channel WWPN 128
Fibre Channel host ports per host object (ID)
32
iSCSI Host Properties 
iSCSI hosts per system FS5015 256
FS5035 512
FS5200
1,024
iSCSI hosts per I/O group
256
iSCSI names per host object
4
iSCSI names per I/O group
512
iSCSI Hardware Properties 
10Gbps Ethernet ports per system FS5200 2 Onboard ports
iSER Host Properties
iSER hosts per system FS5200 1024
iSER hosts per I/O group FS5200 256
iSER names per host object FS5200 4
SAS Host Properties
SAS hosts per system FS5015 4
FS5035 8
FS5200 16
SAS hosts per I/O group 4
Adapter Hardware Properties
4-port 16 Gbps FC adapters per node / canister
FS5015
FS5035
 1
FS5200 2
2-port 32 Gbps FC adapters per node / canister
FS5015
FS5035
 N/A
FS5200 2
4-port 10 Gbps Ethernet adapters per node / canister 1
On board 1 Gbps Ethernet I/O ports per node / canister
FS5015
FS5035
 1 Technician port
FS5200 N/A
On board 10 Gbps Ethernet I/O ports per node / canister
FS5015
FS5035
 N/A
FS5200 2
2-port 25 Gbps iWARP adapters per node per canister
FS5015
FS5035
 1
FS5200 2
2-port 25Gbps RoCE adapters per node / canister
FS5015
FS5035
 1
FS5200 2
NVMe over Fibre Channel Host Properties 
FC-NVMe hosts per system FS5200 64 This limit is not policed by the IBM Storage Virtualize software. Any configurations that exceed this limit can experience significant adverse performance impact.
FC-NVMe hosts per I/O group
FS5200
16
 This limit is not policed by the IBM Storage Virtualize software. Any configurations that exceed this limit can experience significant adverse performance impact.
Fibre Channel Logins per FC-NVMe WWPN FS5200 16 This limit is the number of FC2 logins supported.
NVMe Qualified Names (NQNs) per host object (ID)
FS5200
2
NVMe over RDMA hosts per system FS5200 512
NVMe over RDMA hosts per I/O group FS5200 256
Primary RDMA connections per port FS5200 256
Copy Services Properties 
Total Metro Mirror, Global Mirror, and HyperSwap capacity per I/O group 1,024 TB This limit is the total capacity for all master and auxiliary volumes in the I/O group.
Remote Copy (Metro Mirror and Global Mirror) relationships per system FS5015
2,048
 A mix of Metro Mirror and Global Mirror relationships is allowed
FS5035
FS5200
 8,192
Remote Copy migration relationships per system 256
Maximum round-trip latency for Metro Mirror, HyperSwap, and Migration relationships 3ms
Global Mirror cycling mode relationships (also known as GMCV) per system, with cycle times less than 300 seconds 256
Global Mirror cycling mode relationships (also known as GMCV) per system, with cycle times of 300 seconds or more FS5015 1,024
FS5035
FS5200
 2,500
Active-Active Relationships (HyperSwap) FS5015 N/A
FS5035 1,250 Limit for the number of HyperSwap volumes in a system
FS5200 2,000
Maximum round-trip latency for Global Mirror and Global Mirror cycling mode (also known as GMCV) when using FC replication 80ms 250ms in certain zoning
Remote Copy relationships per consistency group for Metro Mirror, Global Mirror, and Active-Active (HyperSwap) relationships
-
 No limit is imposed beyond the Remote Copy relationships per system limit.
 
Remote Copy relationships per consistency group, for Global Mirror cycling mode relationships (also known as GMCV) 256
Note the I/O pause time at the start of each cycle increases in proportion to the number of relationships in the consistency group.
Refer to the Changes to support for Global Mirror with Change Volumes page for information relating to GMCV performance considerations and best practice.
Remote Copy consistency groups per system
256
3-site Remote Copy (Metro Mirror) relationships per consistency group 256
3-site Remote Copy (Metro Mirror) consistency groups per system 16
3-site Remote Copy (Metro Mirror) relationships per system FS5015 1,024
FS5035 1,250
FS5200 2,048
3-site HyperSwap Remote Copy relationships per system FS5015 N/A
FS5035
FS5200
 1,250
FlashCopy Properties
FlashCopy mappings per system FS5015
2,048
FS5035
FS5200
 8,192
FlashCopy consistency groups per system 500
FlashCopy mappings per consistency group 512
FlashCopy targets per source
256
Snapshots per system
FS5015
FS5035
 N/A
FS5200 15,863
Snapshots per volume copy
FS5015
FS5035
 N/A
FS5200 15,863
Thin-Clone, Clone Volumes per system
FS5015
FS5035
 N/A
FS5200 8,191
Thin-Clone Volumes per Source Volume
FS5015
FS5035
 N/A
FS5200 8,191
Clone Volumes per Source Volume
FS5015
FS5035
 N/A
FS5200 8,191
Total FlashCopy bitmap Allowance
- of which legacy FlashCopy can have up to
 2 GiB
2 GiB
Total FlashCopy volume capacity per I/O group
- of which legacy FlashCopy can have up to
 4 PiB
4 PiB
Safeguarded policies per system 32 Includes 3 predefined and 29 user-defined policies
Snapshot policies per system 32
Safeguarded volumes per system
8,192
Safeguarded volume groups per system
256
Safeguarded volumes per volume group
512
Replication Properties
Policy-based replication
Policy-based replication capacity per I/O group FS5200 1,024 TiB
Policy-based replication replicated volumes per system FS5200 7,932 Volumes per system / 2
Volume groups per system using policy-based replication FS5200 1,024 No limit beyond system limit - volume groups per system
Volumes per volume group using policy-based replication FS5200 512 No limit beyond system limit - volumes per volume group
Maximum round-trip latency for asynchronous policy-based replication that uses Fibre Channel partnerships FS5200 250ms
Maximum round-trip latency for asynchronous policy-based replication that uses IP partnerships FS5200 80ms
Maximum replication policies per system FS5200 32
Maximum I/O groups that use policy-based replication FS5200 2
IP Partnership Properties 
Inter-cluster IP partnerships per system
3
 A system can be partnered with up to three remote systems.
Inter-site links per IP partnership
2
 A maximum of two inter-site links can be used between two IP partnership sites.
Ports per node
1
 A maximum of one port per node can be used for IP partnership.
IP partnership Software Compression Limit
FS5015
FS5035
 140 MB/s
FS5200 N/A
Internal Storage Properties 
SAS chains per control enclosure FS5015 1
FS5035
FS5200
 2
Enclosures per SAS chain
10 x 2Uxx
Or
4 x 5U92
Expansion enclosures per control enclosure FS5015 10
FS5035
FS5200
 20
Expansion enclosures per system FS5015 10
FS5035 40
FS5200 80
Drives per I/O group FS5015 392
FS5035 504
FS5200 748
Drives per system FS5015 392
FS5035 1,008
FS5200 2,992
SCM drives per I/O group 12
Distributed RAID Array Properties 
Arrays per system 32
Encrypted arrays per system 32
Arrays per I/O group
10
Member Drives per array
128
FCM arrays per storage pool 1 Existing multi-array storage pools created before 8.5.0 are supported as 'grandfathered'
Minimum-Maximum member drives per RAID-1 array
2-16
Minimum-Maximum member drives per RAID-5 array
4-8
Minimum-Maximum member drives per RAID-5 array (NVMe drives) FS5200 4-8
Minimum-Maximum member drives per RAID-6 array
6-128
Minimum-Maximum member drives per RAID-6 array (NVMe drives) FS5200 6-24
Rebuild areas per non-FCM array
1-4
Rebuild areas per FCM array FS5200 1
Rebuild areas per non-FCM RAID-1 array (2 drives only) 0
Rebuild areas per non-FCM RAID-1 array (>2 drives)
1
Rebuild areas per FCM RAID-1 array
(2 drives only)
 0
Rebuild areas per FCM RAID-1 array
(>2 drives)
 1
Minimum-Maximum stripe width for RAID-5 array
3-7
Minimum-Maximum stripe width for RAID-6 array
5-16
Maximum drive capacity for RAID-5 arrays
8 TB
 This limit applies to HDDs
Maximum drive capacity for RAID-1 arrays 8 TB This limit applies to HDDs
Drives added to an array in a single DRAID expansion
12
 for DRAID-1
42 for DRAID-5 and DRAID-6
Concurrent DRAID expansions per system
4
Concurrent DRAID expansions per parent storage pool
1
Compressed DRAID arrays per storage pool 1
External Storage System Properties 
Storage System WWNNs per system (cluster)
1,024
Storage System WWPNs per system (cluster)
1,024
WWNNs per Storage System
16
WWPNs per WWNN
16
WWPNs per MDisk 16 WWPNs per MDisk means the limit of Storage System WWPNs that can have LUN mappings for a specific Storage System Logical Unit (LU)
LUNs (managed disks) per Storage System
-
 No limit is imposed beyond the managed disks per system limit
System and User Management Properties 
User accounts per system
FS5015
FS5035
 200 Includes the default user accounts
FS5200
400
User groups per system
256
 Includes the default user groups
Authentication services per system
1
DNS servers per system 2
NTP servers per system
1
iSNS servers per system
1
Concurrent OpenSSH sessions per system
32
Two Person Integrity Requests per system 4
Patches per cluster 7
Patches per node (Includes Installed, Obsolete, and Error) 30
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
LDAP servers per system
6
REST API Properties 
Threads per session
64
HTTP header size
16 KB
 

Extents 

The following table compares the maximum volume, MDisk, and system capacity for each extent size.

Extent size (MB) 
Maximum non thin-provisioned volume capacity in GB
Maximum thin-provisioned volume capacity in GB (for regular pools) 
Maximum compressed volume size (for regular pools) ** 
Maximum thin-provisioned and compressed volume size in data reduction pools in GB
Maximum total thin-provisioned and compressed capacity for all volumes in a single data reduction pool per I/O group in GB
Maximum MDisk capacity in GB 
Maximum DRAID MDisk capacity in TB 
Total storage capacity manageable per system * 
16
2,048
(2 TB)
2,000
2 TB
2,048
(2 TB)
8,192
(8 TB)
2,048
(2 TB)
32
64 TB
32
4,096
(4 TB)
4,000
4 TB
4,096
(4 TB)
16,384
(16 TB)
4,096
(4 TB)
64
128 TB
64
8,192
(8 TB)
8,000
8 TB
8,192
(8 TB)
32,768
(32 TB)
8,192
(8 TB)
128
256 TB
128
16,384
(16 TB)
16,000
16 TB
16,384
(16 TB)
65,536
(64 TB)
16,384
(16 TB)
256
512 TB
256
32,768
(32 TB)
32,000
32 TB
32,768
(32 TB)
131,072
(128 TB)
32,768
(32 TB)
512
1 PB
512
65,536
(64 TB)
65,000
64 TB
65,536
(64 TB)
262,144
(256 TB)
65,536
(64 TB)
1,024
(1 PB)
2 PB
1,024
131,072
(128 TB)
130,000
96 TB ** 
131,072
(128 TB)
524,288
(512 TB)
131,072
(128 TB)
2,048
(2 PB)
4 PB
2,048
262,144
(256 TB)
260,000
96 TB ** 
262,144
(256 TB)
1,048,576
(1 PB)
262,144
(256 TB)
4,096
(4 PB)
8 PB
4,096
262,144
(256 TB)
260,000
96 TB ** 
262,144
(256 TB)
2,097,152
(2 PB)
524,288
(512 TB)
8,192
(8 PB)
16 PB
8,192
262,144
(256 TB)
260,000
96 TB ** 
262,144
(256 TB)
4,194,304
(4 PB)
1,048,576
(1 PB)
16,384
(16 PB)
32 PB

* The total capacity values assume that all of the storage pools in the system use the same extent size. 
** See the following Flash

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Document Information

Modified date:
08 May 2024

UID

ibm16854961

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