FlashSystem machine types, models and product identifiers
The full machine type and model identify a particular enclosure or system offering. A family name alone can cover several chassis and drive arrangements. Order features and service FRUs retain their separate roles; keep each identifier with the model and source context that defines it.
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Control enclosures, node canisters and expansion shelves
A control enclosure contains the controller hardware and its internal drive positions. Node canisters provide processing and connectivity functions. An expansion shelf adds supported drive positions through its attachment connections. A shelf’s dimensions and drive count do not add another control enclosure.
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Internal bays and maximum drive counts
Internal drive positions are the physical bays in the named enclosure. A system maximum can include expansion shelves, and a cluster maximum can include several systems. Keep the enclosure, system and cluster counts separate before calculating capacity or rack space.
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System memory, node cache and paired upgrades
Cache is working memory used by storage controllers. It is separate from the drives holding application data. A per-canister figure and a whole-system memory total have different scopes. An upgrade can require a matched arrangement across node canisters rather than a single module.
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Nominal, raw, usable and effective capacity
A drive’s named capacity, its physical raw media and the usable space after protection are different figures. Effective capacity also assumes data reduction. Keep the exact basis used by the model’s table; a summed nominal FCM figure is not automatically usable application space or physical NAND capacity.
FlashSystem 9500: keep nominal internal FCM totals separate from effective and expansion figures.
IOPS, read hits and read misses
IOPS means input/output operations per second. Block size and read/write mix affect the result. A read hit is served from cache; a read miss needs data from storage. Compare the same test context and configuration rather than treating the largest published IOPS as a workload guarantee.
FlashSystem 5045: compare its cached-read and read-miss performance contexts.
Storage bandwidth and host line speed
Bandwidth describes data transferred per second, often in GB/s. Host links commonly state Gb/s, which counts bits rather than bytes. Protocol overhead and workload also matter. A clustered bandwidth figure must remain separate from a single enclosure’s rating.
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Storage latency and published minimums
Latency is the time taken to complete an I/O operation. A published minimum describes its test conditions rather than every application request. Read-hit, read-miss and mixed-workload latency can differ; compare measured workload latency alongside the stated system configuration.
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FlashCore Module generations and capacities
FlashCore Modules combine flash storage with IBM controller functions. FCM1 through FCM5 identify different generations, not interchangeable capacity labels. Match the exact generation and feature to the enclosure and installed software. Standard NVMe drives do not automatically provide the same compression or computational functions.
Industry-standard NVMe and EDSFF drives
NVMe is a storage protocol; EDSFF describes an enterprise drive form-factor family. Neither name alone confirms that a drive fits a FlashSystem enclosure. Use the model’s supported drive generation, capacity and identifier when planning a replacement or expansion.
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Storage Class Memory: SCM
Storage Class Memory is a distinct low-latency storage option on the models and software levels that support it. It is separate from controller cache and ordinary NAND SSD options. Keep its drive capacity and exact support context with the selected enclosure.
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SAS SSDs, HDDs and nearline disks
SAS is Serial Attached SCSI. A SAS SSD uses solid-state media, while an HDD uses rotating disks. Nearline disks emphasize capacity and have different performance characteristics from higher-speed enterprise disks. Match the carrier and supported enclosure before ordering a replacement.
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SFF, LFF and high-density shelves
SFF and LFF describe small and large drive formats. A high-density shelf packs more positions into its enclosure and has its own rack, weight and service requirements. A supported SAS shelf is not a direct substitute for an internal NVMe drive bay.
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Fibre Channel host attachment
Fibre Channel carries storage traffic through compatible host adapters and SAN connections. Link speed and port count describe connection resources rather than guaranteed application bandwidth. Match host, switch and optics support with the FlashSystem software level.
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Ethernet, iSCSI and NVMe over TCP or RDMA
Ethernet is the network connection. iSCSI and NVMe/TCP are storage protocols carried over supported Ethernet arrangements. RDMA-based NVMe uses a supported RDMA design. Adapter support for one protocol does not imply support for every protocol at the same speed.
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Adapter slots, ports and transceivers
Adapter slots hold supported interface cards. Ports are the connections on those cards or the enclosure. A transceiver provides the physical optical or electrical interface. Check the system port limit as well as card count, speed and the required optics.
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SAS expansion attachment
Expansion SAS connections attach supported shelves to the controller. They serve a different role from host-facing Fibre Channel or Ethernet ports. Match enclosure model, cable type and supported chain layout rather than assuming an advertised SAS speed establishes compatibility.
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RAID protection and usable drive capacity
RAID uses a supported arrangement of drives to protect data against specified drive failures. Protection, spare capacity and system overhead reduce the space available for applications. A raw drive total therefore cannot be quoted as usable capacity without the selected layout.
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IBM Storage Virtualize and minimum software levels
Storage Virtualize is the storage software family used by supported FlashSystem models; older releases use the Spectrum Virtualize name. Drive, adapter and data-service support depends on the model and release. Keep a published minimum with its exact feature rather than applying it to every option.
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Hosts, host ports, IDs and mappings
A host object represents a server attachment. Host ports and identifiers describe its connections. A mapping makes a volume available to a host. Maximum hosts, host ports and mappings are separate limits, so one larger number cannot replace the others in a configuration plan.
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NVMe hosts and qualified names
An NVMe host uses the supported NVMe-over-fabrics attachment. An NVMe Qualified Name, or NQN, identifies an NVMe host or subsystem. Host counts and NQN counts are different limits. Keep NVMe/FC, NVMe/TCP and NVMe/RDMA limits with their own protocol.
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Volumes, managed disks, pools and volume groups
A volume is logical storage presented for use. Managed disks provide capacity to storage pools, and volume groups organize supported management or policy operations. Maximum volume size, volume count and total managed storage describe different constraints.
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Compression, deduplication and data-reduction pools
Compression reduces data representation; deduplication avoids retaining repeated data. A data-reduction pool uses supported efficiency functions. Savings depend on the stored data and enabled features. Already compressed or encrypted data may not deliver the reduction assumed by an effective-capacity figure.
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FlashCopy, snapshots and Remote Copy
Snapshots and FlashCopy mappings describe point-in-time copy functions. Remote Copy relationships replicate data between supported configurations. A mapping or relationship limit is a software resource limit, not extra drive capacity. Retention and recovery planning still need usable space and a supported topology.
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HyperSwap and high-availability relationships
HyperSwap provides supported dual-site access to storage volumes. Its relationships and topology have their own software and attachment requirements. It is separate from taking a backup or retaining a historical copy. Check the complete site arrangement before counting the advertised relationship maximum.
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Encryption features and key management
Encryption protects stored data using the supported encryption arrangement. An enablement feature, an encrypted drive and a key-management service have different roles. Retain the model’s exact feature context and plan key access for recovery before changing hardware or software.
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FlashSystem Grid, clustered systems and scale
A FlashSystem Grid coordinates supported storage systems through shared management and operations. A clustered-system limit can describe a different topology. Retain the model’s stated scope for systems, enclosures and effective capacity; do not multiply a single-enclosure specification without the supported arrangement.
FlashSystem 7600: compare the single-enclosure and FlashSystem Grid scopes.
FlashSystem withdrawal and support milestones
Withdrawal from marketing and end of standard support describe different dates. A recommended replacement identifies a model to evaluate, not a promise that existing drives or licences move to it. We check the installed software, host attachment and migration requirements with the proposed replacement.
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FlashSystem power supplies, rack fit and service parts
A replacement supply or canister must match its enclosure and service identifier. Rack height is only one room requirement; depth, loaded weight and service clearance also matter. Send the full machine type and serial number with the installed part label for a repair quote.
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Host connectivity and storage protocols
Host connectivity describes the connections between application servers and the FlashSystem. Fibre Channel and Ethernet use different physical interfaces and supported protocols. Keep the exact adapter, port count and protocol with the host operating system and storage software level. Front-end host ports serve a different role from expansion-shelf connections.
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