How and where you store your records is key to ensuring they remain full and accurate for the entire time they need to be kept.
Records must be kept safe, stored in appropriate conditions, and preserved to reduce their deterioration.
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When looking at storage for digital records, you need to think about the mode of storage, the technologies or media you store them on, and where the media itself is stored.
Choose digital storage based on:
- how often you need to access the records
- access restrictions for the records
- the file format
- how long you need to keep them
- the best way to preserve and manage the records
- what options are available.
Most digital storage devices have a limited life expectancy of around 5 to 7 years.
- the specific combinations of hardware and software needed to access the information
- moving records across to new media before the storage devices or related equipment become unsupported or obsolete
- the media you choose and how long you will be able to use it
- security or access restrictions that may rely on the specific format or storage media.
Consult with your IT area or specialist about storage media and file formats.
There are 4 main ways to store digital records:
Note: There are additional recordkeeping considerations when using cloud-based storage and services.
Storage media is usually either:
- Solid state media–data is stored in ‘flash memory’ rather than rotating disks or optical media (e.g. USB flash drive or thumb drive, SD and CF cards used in cameras). Some newer portable hard drives and external storage devices are solid state media.
- Magnetic media–information is recorded and retrieved in the form of a magnetic signal (e.g. floppy disks, magnetic hard disks, magnetic tape, including reels, cassettes and cartridges).
- Optical media–information is read optically (by a laser) (e.g. CDs, DVDs). These may be one use only or reusable. Rewritable optical discs–also known as EO (erasable optical) disks–allow the user to record information on a disc, erase it, and replace it with new data. The most common forms of rewritable discs are CD-RW and DVD-RW.
Note: there are additional recordkeeping considerations when using cloud-based storage and services.
Assess storage media using these criteria:
Availability and speed
If records need to be accessed often or quickly, choose a storage mode with a fast retrieval time.
The longevity or lifespan of media depends on the type, format, quality of manufacture, frequency of handling and proper storage conditions.
Most media will only last 5 to 7 years. Even if storage media is capable of lasting longer under appropriate storage conditions, the hardware or software required to access the information may become obsolete
The selected media should be robust with have a clearly defined migration path and widespread industry support.
Think about your current and future needs when considering capacity.
Robust error detection and integrity checks (e.g. checksums) should be used to ensure there has been no inadvertent change, deterioration or data loss.
Make sure that the media and/or the technology or hardware required to read the media isn’t likely to become obsolete or unsupported in the near future.
Some older optical media and magnetic hard disks, tapes, cartridges and proprietary flexible disks (e.g. Bernoulli, Zip or Jaz disks) are at risk of obsolescence if they are dependent on specific operational environments or hardware.
The cost of storage should include the:
- capacity of storage media (e.g. storage space per gigabyte)
- hardware and software required to access the media or read the information
- special storage environments
- resources required for active management, monitoring, integrity checking and support.
You should consider the published failure rate or mean time to failure (if known) of the hardware.
The susceptibility of media to damage depends on the type, format, quality of manufacture, handling and treatment, and proper storage conditions.
You should implement controls to protect the media from damage during handling and usage.
Solid state media
Solid state storage devices are generally quite robust, but can be vulnerable to power variations, physical shock and high temperatures and humidity.
Magnetic media has particles that retain the coded information in a magnetic layer. These particles can become unstable, leading to a gradual loss of signal quality and eventually to total information loss.
Flexible magnetic disks are prone to catastrophic loss of data due to physical degradation and exposure to magnetic fields.
Magnetic tapes in humid environments are also particularly susceptible to mould.
The critical portion of an optical disc is the data layer, which can be damaged relatively easily. Small amounts of degradation can cause significant information loss.
Optical media are susceptible to:
- solvents–they can affect the lacquer layer and subsequently the metal layer on a CD
- markings or deposits (e.g. scratches, fingerprints) on the data side
- age related damage–the polycarbonate plastic layer tends to slowly lose shape, making them difficult to read
- mould, moisture and dust
- high or dramatic and sudden changes in temperature and humidity, including direct sunlight
- corrosion of the metal layer–certain metals, such as gold, are more resistant to corrosion than others
- inks, adhesives from labels and damage from writing implements–even on the ‘label’ side, they can easily damage or corrode the plastic or lacquer layer, and subsequently the metal layer.
Storage for magnetic and optical media must have controls in place to reduce the risks.
- Temperature and humidity should be as constant as possible.
- Avoid power variations or power spikes.
- Avoid paper and cardboard enclosures, and remove paper (e.g. information booklets) from cases as they generate dust and increase moisture.
- Media should be stored upright. Media should not be stacked, stored horizontally or packaged so that they lean against each other.
- Hard disks which are not part of networked storage should be stored in anti-static bags.
- Earth metal storage shelves.
- Magnetic disks should remain powered as intelligent storage arrays can test for data corruption and self-repair (within limits). If disks must be powered down for extended periods, they should be ‘parked’ according to manufacturer instructions.
- Media should be stored in reasonably dust-proof cases made of an inert plastic, such as polypropylene, or non-magnetic material. Polyvinylchloride (PVC) is unsuitable because it contains substances that may be damage the media.
- Tape cases should have fittings to hold the tapes in position by the hub–they should be strong enough to protect the cassettes from physical damage and they should close tightly to keep out dust particles.
- If optical discs must be labelled, use a water-based felt-tip permanent marker to mark the label side of the disc. Do not use ballpoint pens, pencils or adhesive labels.
Storage facilities for physical records, digital storage media and data storage centres should:
- be in a suitable location and be well designed, constructed, and maintained
- be able to control environmental conditions and protect against excessive light, dust, dirt, dampness, heat, pests and mould
- offer suitable housing for records with different requirements such as shelving for boxes, and cabinets or drawers for maps and plans
- be secure from unauthorised access
- provide protection from damage and disaster (e.g. facility is not in a high-risk location, and check that it has a disaster management plan and damage prevention processes)
- allow appropriate access to the records.
Use the records storage standard criteria assessment tool as a checklist to assess your current and future storage, and identify any areas for improvement.
See a list of available commercial off-site storage providers.
Note: If you are using off-site storage, sentence records before you transfer them off-site to make things easier when the time comes for disposal.
The Queensland State Archives' storage standards are a voluntary code of best practice. Use this to assess storage facilities and conditions for both physical and digital records.
The storage standard is based on 9 principles covering physical, administrative and systemic controls.
- Location–storage facilities are conveniently located and away from known hazards.
- Facility design and construction–storage facilities are specifically designed to protect and preserve records.
- Environmental control–storage facilities provide environmental conditions that are appropriate to records’ formats and retention periods.
- Shelving and packaging–records are protected from damage and slow deterioration.
- Accessibility–records can be easily identified, located and retrieved.
- Handling–records are retrieved, handled and used in a manner that prevents damage and slows deterioration.
- Privacy and security–storage conditions ensure the privacy and security of the records.
- Protection from disaster–disaster management programs are established and maintained to minimise risks.
- Monitoring and maintenance–storage facilities are monitored, managed and maintained to ensure records’ safety.
Storage standards for magnetic and optical media
There are additional storage requirements for magnetic and optical media.
Magnetic tape should be stored as specified in ISO 18923:2000 Imaging materials–Polyesterbase magnetic tape–Storage practices.
Regular use of magnetic media should be in accordance with ISO 18933:2012 Imaging materials–Magnetic tape–Care and handling practices for extended usage.
Optical media should be stored as specified in ISO 18925:2008 Imaging materials–Optical disc media–Storage practices.
Offline media should be stored at less than 20°C. For long-term storage, less than 18°C and 40% relative humidity is recommended. For very long-term storage (decades), the temperature and humidity should be lower, however, magnetic media should not be stored below 8°C.
|Quality of manufacture||Lifespan in years at 30ºC and 40% relative humidity||Lifespan in years at 20ºC and 30% relative humidity||Lifespan in years at 10ºC and 25% relative humidity|
|Very high quality media||10–20||20–50||50–100|
Environmental levels need to be stable. Mould will start to grow at around 60% relative humidity and if the humidity fluctuates more than 10% in 24 hours.
Exposure to ultraviolet (UV) light will also hasten media degradation. Fluorescent tubes with UV filters should be used in storage areas, and turned off when not in use. UV light can be easily measured with a light metre, and levels should not exceed 75μW/lumen. An ideal storage area would have no windows, but if windows are present, they should be covered with curtains or blinds.
Appropriate environmental conditions will slow the deterioration of physical records while poor environmental conditions damage them. Damage will be incremental and cumulative which may take some time to become apparent.
Recommended environmental levels and tolerances will depend on how long records need to be kept and their format. The longer the records need to be kept, the more critical environmental controls are.
Appropriate storage conditions for long-term temporary and permanent records must be maintained on a 24/7 basis.
Temperature and Relative Humidity (RH)
A constant temperature and RH levels should be maintained within specific tolerances. Controlled temperature and relative humidity will help prevent both physical and chemical degradation of records, damage to data storage and media, and the threat from pests and mould.
Magnetic and optical media are particularly susceptible to temperature and humidity changes, and mould growth.
Find out about the recommended temperature and relative humidity levels according to format type and retention period.
Records storage areas need to be kept clean and free of dust and dirt, especially for long-term temporary and permanent records.
Particulates such as dust, dirt and soot should be filtered. 60–80% of dust particles that are more than half a micron in diameter give up to a total 50 micrograms of particles (solids) in a cubic metre volume of air sampled.
Gaseous pollutants including sulphur dioxide, nitrogen gases and ozone should each not exceed 5–10 parts per billion by volume.
Similarly acetic acid and formaldehyde levels should not exceed 4 parts per billion by volume.
Light should be managed to exclude ultraviolet sources or be filtered to remove it. Minimise overall light intensity and reduce exposure times.
Some common materials will damage records if used long term, or left on or in contact with records.
Store solid state media in anti-static bags and earth metal shelving.
Avoid timber and composites. All shelving and cabinets should be powder coated or baked enamel metal (unless otherwise specified). They must fully contain the records (i.e. no overhang or protrusion).
Long-term temporary and all permanent unbound records should be contained. Containers and wrapping materials should meet NAA archival quality standard and/or photographic activity test (unless otherwise stated).
Other materials can damage physical records. Avoid using metal clips and fasteners such as bull dog clips, sticky tape, some cardboard and plastics, laminates, post-it notes, and sticky tabs.
Find out what compatible materials, shelving, containers and wrappings to use according to format type.
Any digital storage media that relies on power should remain powered whenever possible. For solid state and magnetic media, avoid power variations (power spikes).
Avoid physical shock to storage media.
Be aware of the life of the format or media, for example, memory wear on solid state media (i.e. the number of times data can be rewritten before the device is damaged).
Find out what other conditions and requirements you should meet according to format type.
Recommended specific storage and environmental conditions
Find out what recommended storage and environmental conditions , shelving, compatible materials and containers to use.