Category: Logical Devices (Client)#

The Logical Devices (Client) category documents the logical storage devices (LUNs, volumes) assigned to a server from a SAN storage system. It is a multi-value category -- a server can use many LUNs from different storage systems simultaneously.

This category shows the consumer side of the SAN storage assignment: Which LUNs does this server see, through which paths does it reach them, and which multipath technology provides redundancy? The counterpart on the storage side is the Logical Devices (LDEV Server) category, in which the LUNs on the storage array itself are documented.

Usage#

Typical use cases:

• Document LUN assignments: In SAN environments, the question "Which LUNs are assigned to which server?" is one of the most frequent requests to the storage team. The Logical Devices (Client) category answers this question directly on the server object, without having to connect to the storage management console.
• Multipath documentation: The Multipath technology field documents which multipath framework is used -- e.g. DM-Multipath (Linux), PowerPath (Dell EMC), RDAC, or Windows MPIO. This information is critical for troubleshooting during path failures, because each technology has its own diagnostic tools and configuration specifics.
• Path analysis: The Path field shows through which FC ports and HBAs the LUN is reachable. In the event of an HBA failure, you can immediately identify which LUNs are affected and whether the remaining path is sufficient.
• Prepare storage migration: When migrating from an old to a new storage system, the category shows which servers use which LUNs. This is the foundation for the migration plan: which servers need to be switched over, which new LUNs are needed, and which paths need to be configured?
• Capacity planning: In combination with the storage-side LDEV Server entries, a complete overview of which servers use how much SAN storage emerges -- helpful for budget planning and procurement of additional capacity.

Fields#

Title#

The name of the logical device as the server sees it, e.g. sdb, dm-3, LUN 42, or the volume label. Use the designation that the operating system administrator also knows, so that the assignment is unambiguous.

Path#

The FC port paths through which the logical device is reachable. Here the FC ports are linked through which the server accesses the LUN. In a multipath configuration, a logical device typically has two or four paths -- ideally through different HBAs and fabrics.

Logical Devices (LDEV Server)#

The link to the storage-side LDEV Server entry. This field establishes the connection between the client view (server) and the server view (storage array). Through this link, navigation is possible: from the server to the LUN configuration on the storage system and vice versa.

Primary Path#

The preferred path for I/O operations. In active/passive configurations (e.g. ALUA with preferred path), this is the path through which data flows during normal operation. In active/active configurations, this value can be used to designate the optimized path.

Multipath Technology#

The multipath framework used, e.g. DM-Multipath, PowerPath, Windows MPIO, NativeMPIO, or RDAC. Dialog+ field -- custom values can be added. The multipath technology determines the diagnostic tools and failover behavior, making this information essential during disruptions.

Description#

Free text for additional information: LUN ID on the storage system, file system type (ext4, XFS, NTFS), mount point, capacity, performance tier (SSD/HDD), or usage notes (e.g. "Oracle Tablespace DATA").

Technical Reference#

Fields (API Reference)#

API Examples#

Create an entry#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.save",
    "params": {
        "apikey": "your-api-key",
        "object": 1042,
        "category": "C__CATG__LDEV_CLIENT",
        "data": {
            "title": "dm-3 (LUN 42)",
            "assigned_ldevserver": 2055,
            "multipath": "DM-Multipath",
            "description": "Oracle Tablespace DATA, XFS, 500 GB, Performance-Tier SSD, LUN-ID 42 auf NetApp FAS8700"
        }
    },
    "id": 1
}

Read entries#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.read",
    "params": {
        "apikey": "your-api-key",
        "object": 1042,
        "category": "C__CATG__LDEV_CLIENT"
    },
    "id": 2
}

Update an entry#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.save",
    "params": {
        "apikey": "your-api-key",
        "object": 1042,
        "category": "C__CATG__LDEV_CLIENT",
        "entry": 9,
        "data": {
            "assigned_ldevserver": 3010,
            "description": "2026-04: LUN-Migration von NetApp FAS8700 (LUN 42) auf Pure Storage FlashArray (Vol oracle-data-01)"
        }
    },
    "id": 3
}