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SAN (Storage Area Network)
In brief
A SAN (Storage Area Network) is a dedicated, fast network through which servers access central storage systems as if they were local hard drives. The storage is divided into logical units, so-called LUNs, which are assigned to individual servers. When a data center is dismantled, SAN systems often contain hundreds of drives with company data that must be erased or destroyed individually.
Structure and distinctions
A SAN consists of storage systems with many hard drives or SSDs, switches, and adapters in the servers. Typical protocols are Fibre Channel and iSCSI. Servers see the storage as block devices on which they create their own file systems.
| Term | Access | Typical use |
|---|---|---|
| SAN | Block level over a dedicated storage network | Databases, virtualization |
| NAS | File level over the normal network | File shares, backups |
| DAS (Direct Attached Storage) | connected directly to the server | individual servers |
More on file storage in the entry NAS.
What to consider when dismantling
Data in a SAN is distributed across many drives, usually in a RAID array. For decommissioning there are two levels: as long as a system keeps running, individual LUNs can be erased logically, for example before returning them to a leasing provider. More on this in the entry LUN erasure. If the system is taken out of operation, every drive is erased individually and documented by serial number, or destroyed. How a dismantling proceeds is shown in our guide sell used servers. For this, Second IT uses Blancco Drive Eraser and, for storage environments, Blancco LUN Eraser, with a certificate for each device.
Frequently asked questions about SAN
What is the difference between SAN and NAS?
A SAN provides storage at block level over a dedicated network, a NAS provides files over the normal network. SANs are designed for high performance for servers, NAS for shared file storage.
Is it enough to erase the LUNs before decommissioning?
Not for a system that is being taken out of operation completely. Spare drives, caches, and failed drives may contain data. Every physical drive should be erased or destroyed and documented individually.
Do used SAN systems still have value?
That depends on age, manufacturer, and maintenance status. A valuation based on the device list with models and serial numbers provides clarity.
What is a LUN in a SAN?
A LUN is a logical unit into which the storage of a SAN is divided. It is assigned to individual servers. The servers see it as a block device and create their own file systems on it.
What does a Storage Area Network consist of?
Of storage systems with many hard drives or SSDs, of switches, and of adapters in the servers. Typical protocols are Fibre Channel and iSCSI. The data is usually distributed across many drives in a RAID array.
Dismantle storage systems – every drive verifiably erased.
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