Offline storage

Last updated:

June 15, 2025

What do we mean by offline storage?

Offline storage is used to store records culled from the primary system as they are no longer current, have a low access rate, or require additional layers of security. Offline storage may be referred to as removable storage, backup storage or cold storage and may refer to digital records held on:

servers kept independently of the system
individual removeable pieces of media, including external hard drives, NAS devices, USB/flash memory drives/SD cards, magnetic tape, CDs/DVDs, or older media housing records
cloud devices that are similar in functionality to the first two points.

The key characteristic of offline storage is that the information held on it is not immediately accessible. It must be retrieved, loaded, and possibly processed before it can be accessed. This often-manual step takes longer and requires more effort than accessing records from online storage.

Online storage may appear to be offline in situations where it is separated from a main system. If the records held in storage are always accessible, they are not being held offline. Some examples of online storage that may appear to be offline include:

back-up or disaster recovery regimes of any type as the information is always accessible online and the back-up is an additional copy
hierarchical storage systems as the primary copy never leaves the system. The removable pieces of media are managed by the system and loaded automatically
any form of cloud storage as the storage is still conceptually part of the system
isolated systems as even though they are not connected to anything, the primary copy is still held in the system.

When is offline storage backup storage?

If the records must be retrieved, loaded and possibly processed before they can be accessed, and are not accessible already within the system (which as copies, backup records should be) then it may be considered offline storage.

Backup technologies guard against hardware/software failure or operator error as part of disaster recovery/business continuity programs. They contain an additional copy of records and may be stored in a cloud environment or on an external server or other media.

If the backup technology is being used to archive data and records not stored elsewhere, the data/records must be managed in accordance with the recordkeeping Standards issued by the Keeper of Public Records regardless of whether the backup is being maintained online or offline. For more information, see the Backup Technologies and Records Management Policy.

Benefits and risks

Benefits of offline storage

Benefit	Description
Increased security	Unauthorised people would need to obtain physical access to the media in order to compromise the records when records are stored offline. Keeping records on physical media means the organisation has direct control over records held so they can implement their own security measures rather than hire a third party. For example, controls may include encryption, physical access, or locking records in a vault or other secure space.
Decreased costs	Offline storage can be located within a building owned/occupied by the organisation rather than hire a third party. This can reduce storage costs as the organisation would not be paying a third-party provider for storage facilities. Instead, storage costs would be covered by the organisation's general building costs. An internet connection is not required to access the records.
Secondary backup layer	An alternative access method may be needed for records during an internet outage or because the internet isn't currently available to enable access through the main system. Offline storage may be a secondary back-up (or failsafe) as part of a hybrid or multilayered approach to maintaining secure backups, to call on should an issue with cloud-based backup services occur.

Risks of offline storage

Risk	Mitigation
Hardware of software failure	Minimise the types of digital media used for storage. Have copies of digital records on at least two different types of media, or on different brands if using the same type of media. Ensure that the media chosen for digital records are the best quality for storing digital records for the duration required. Conduct regular spot checks of digital records stored for errors.
Unable to access or read the records held when required	Use software capable of producing a long-term sustainable format to aid preservation of the record in an accessible and readable format. Have a conversion strategy to ensure that the digital records are maintained and remain readable over time even when converted from one format to another. Have a migration strategy to maintain the digital record over time by being migrated from one storage medium to another to ensure the survival of the bit stream.
Records lost through damage to the media housing them	House media in containers that protect the physical carrier from damage. Handle media appropriately so that the data is not damaged. Store the media at temperature and humidity levels that will preserve the data. Minimise dust and other pollutants to prevent damage to the media. Minimise direct sunlight or UV radiation to prevent them from damaging the media. Store the media away from magnetic electrical fields to prevent damage. Protect media from high-risk areas such as pipes or vents that could result in damage due to water, heat or fire.
Records lose their evidential integrity	Ensure audit logs and unauthorised access checks cover records held in offline storage. Retain records in relation to their context so they remain understandable and useable. Context includes details about the hardware and software required to access and use the records, the business functions and processes the records relate to, lifecycle information such as when they were created, who created them and how long they need to be kept, and so on. Conduct checks to ensure records continue to be understandable when placing records onto digital media, including as part of media refresh programs.
Inadequate security - records held by third party provider	Ensure security provisions prevent unauthorised access and detect tampering. Check access provisions, including exit fees and conditions, and ensure contract clauses are appropriate. Consider whether media is owned by the storage provider or by the organisation, including the implications to records stored, such as the ability for the records to be totally removed from the media if needed when the records are due to be disposed of. Review and mitigate security risks associated with services offered by the provider regarding records held in storage, such as unauthorised access, or security breach.
Inadequate security - in house storage	Provide a dedicated, lockable space for storage of media housing records. Ensure security provisions prevent unauthorised access detect tampering. Review the security needs of records housed in line with the Information Security Manual and Essential Eight and address areas of risk. Have a maintenance plan and appropriate governance structures for the records and media so that the space and security provisions are regularly reviewed and updated.

Managing records held in storage

Governance

Governance includes strategies and other structures required to manage records held in offline storage as part of the broader records management program. Governance structures will need to consider both current and legacy records, as well as current and legacy media used to house records.

Records held in storage must be reliably available and useable when the organisation needs them. This means the records:

are preserved for the duration of their minimum required retention period
are discoverable, accessible and useable when needed
are secure from unauthorised access or alteration
are not lost or damaged.

Current records being stored offline will be using currently available software and hardware, and media, which means the technology required should be readily available. Legacy records may be on media no longer used and require older versions of software to be read or require specialised hardware that isn't used anymore.

Questions to ask when determining how to manage records held in offline storage include the following:

How long will the records need to be kept?
What media is being used to house the records?
Is the metadata captured sufficient for the record to be accessed and understood in context over time?
Will the format used continue to be accessible and understandable for as long as needed?
What equipment (including software) needs to be maintained to ensure ongoing access to records?
What checks and reviews will be needed over time to ensure that the record can continue to be accessible, readable and useable?
What preservation strategies, such as media refresh, migration and conversion, will be needed to preserve the record in context over time?

Records held in offline storage should be regularly monitored so that risk to the records can be identified and mitigated effectively. This may include the following:

Integrity checks, such as checksum verification, to ensure the records have not been compromised
Security checks to ensure records are not at risk of being compromised or lost through unauthorised access
Reviews of the software and hardware required to ensure they remain viable and enable the records to be accessed, read and used
Reviews of the media used to ensure they have not been damaged or compromised in a way that would negatively impact the records
Reviews of the formats records are captured in to ensure they remain viable, accessible and usable
Reviews of the storage environment to ensure it is secure and does not endanger the record
Risk identification and mitigation as part of a regular program of risk management.

The type of media uses to store records will:

have a specific lifespan before what is stored in it begins to degrade, which is often shorter than the duration that records need to be retained for
need to be stored in specific conditions for optimal performance
need to be aligned in particular ways to prevent it from becoming damaged, which can distort or otherwise affect records stored on it
need specific hardware and software in order for records to be accessed and read.

Format

All electronic formats become unreadable and unusable over time. Periodic evaluations need to be undertaken to ensure the formats don't become obsolete. If issues with the format are identified, a preservation strategy will be needed. This may be to convert the record into a new format or to implement other measures to enable the record it its current format to continue to be managed and used.

Records identified as State Archives must be transferred to PROV using the VERS Encapsulated Objects (VEOs) format in accordance with the Victorian Electronic Records Strategy (VERS) for the long-term preservation of digital records so that:

the record along with information about the operating system, the software used to create the record, and the classification scheme and other structures it was used within are preserved
the evidential integrity of the record is protected
the information needed to render the record into a readable format if necessary is provided
the record can be understood in context with the systems that governed its use.

VERS is mandatory for digital records identified in PROV Retention and Disposal Authorities as being State Archives. Records identified as State Archives must be held in long-term sustainable formats as per the Long Term Sustainable Formats Specification. It is highly recommended that long-term temporary records are also held in accordance with this Specification.

Metadata

Records held in offline storage should be captured in context and include the associated contextual metadata to ensure they continue to be understood over time.

Detailed and well labelled metadata files should be captured and include information on the following:

The technology and software used to create the record, its format and other information to enable the record to be opened, read and used
The context of the record, such as relationships to other records, classifications assigned (for example, business and security related classifications), descriptive information (such as identifiers, keywords and so on).

Metadata should conform to PROV's Minimum Metadata Standards.

Disposal

Records held in storage must be retained for the duration of their retention periods and then disposed of lawfully and in a timely manner.

Removing records before their retention period ends is an offence under the Public Records Act. Retaining records for longer than their set retention periods can increase the risk of identity theft or other cyber threats.

Where disposal is applied directly to the media housing the records, there is a danger that the records will be discarded or become inaccessible before their retention period expires, or that they will be over retained.

Commonly used preservation strategies

Media refresh

Media refresh is a process that involves storing in exact copy of a record to the same type of media that it was originally captured on. Nothing is changed about the record except for the piece of media used to house it. Storage technologies or density may change as part of the refresh where needed.

A media refresh strategy will be used in situations where media is near to the end of their lifespan. This tends to be a short-term solution to managing records placed in storage as media and the technology required to use and view it evolve rapidly.

Conversion

Conversion ensures long-term usability of records by converting records from one format to another format.

Conversion is likely to occur in conjunction with a migration strategy or a media refresh strategy. The functionality or the appearance of the records is often affected by the conversion process. Once stored, the record, including metadata, and media used, will need to be regularly checked to ensure that the records remain usable and readable.

Examples of conversion include capturing the information from a database as a Software Independent Archiving of Relational Databases (SIARD) file, or a series of Portable Document Format (PDF) reports. This may result in some loss of the functionality of the record and may change how the information contained in the record is viewed.

Migration

Migration is a change to the tools and system used to manage and access the records, not the format of the record. A migration strategy ensures that records retain their authenticity, integrity, reliability and useability and remain accessible when being moved from one system to another or moved from one type of media to a different type of media.

A migration strategy involves upgrading or changing the software or system used so that records along with their contextual metadata are continually maintained. Upgrading or changing from one system or version of software to another, will impact on how the information is displayed. It may also impact on other aspects, such as the context of the data if metadata fields do not match up correctly and the metadata is lost.