Stutch Data Sees Tape as Long Term Future for Storage
Stutch Data Services are a Sydney-based computer data storage media, hardware and software supply company. With experience in mainframe operations, help desks, systems and network support, data recovery, data destruction, offsite storage, disaster recovery, data protection and storage solutions the company is well placed to advise on data protection issues.
Here Stutch Data Services GM, Richard Stutchbury, comments on the current state of data management and protection in Australia.
Interviewer: What is your view on degaussing and destruction of data in Australia? What are the issues surrounding degaussing and the destruction of data?
Richard Stutchbury: Degaussing is the permanent removal of data from magnetic storage media like tape and hard disk drives. It is done by passing the media through a high strength magnetic field which removes the data and restores the bits to a near zero state. The field strength (gauss) must be at least double the strength of that written data (oersteds) called signal coercivity, and at this degaussing field strength data cannot be recovered.
Degaussing is used in Australia, but is not as common as it should be. Many companies believe that crushing is satisfactory on its own but unfortunately the data is still stored on the tape or hard drive platters or both. This leaves the data open to recovery by forensic processes even if it is in pieces. If the media is degaussed, it can then be crushed but it does not need to be unless there is government, defence, personal or financial data held on it or other audit requirements to consider. This would save a lot of crushing, and tapes and hard disk drives could be recycled in a much cleaner way. Unfortunately most tapes, including LTO tapes and hard disk drives are no longer re-useable once they have been degaussed, equally they are definitely no longer re-useable if crushed. Tape encryption has been used as a way to protect data on tape and hard disks from falling into the wrong hands. This does not remove the need to degauss the tapes and hard disk drives once the data they hold is no longer required as encrypted data is vulnerable to people with the encryption codes or forensic recovery with sufficient time. Lastly, it is a legal obligation for Australian companies to maintain records for tax and legal purposes to defend their position. A similar obligation exists for records with financial and personal information that should be destroyed when they are no longer required to protect the people or companies the information relates to.
Interviewer: Do you think people are aware of how long data is stored on tapes and hard drives?
Richard: Not always, but there are two issues here, firstly that data is stored on a piece or pieces of media until it is removed or it is completely destroyed. This means data is available as long as the media survives in reasonable condition. The second issue is that using the forensic recovery methods mentioned above, an expert can go back up to nine re-writes of the data. Say I had a tape or hard drive used nine times for a full backup of data. It is possible to recover data from each of those backups going back to the first one. Degaussing is the only way to ensure this data cannot be recovered, the most recent or the data from up to nine writes ago.
Interviewer: What is your solution for the removal of data from storage media?
Richard: The best method of complete data removal is degaussing using an electronic magnetic field at least twice the strength of the media’s oersted rating or signal coercivity. Some degaussers use rare earth magnets but they slowly degrade over time and have weaker fields each time they are used. Some storage media like Solid State Disk (SSD) need to be crushed as degaussing will not remove that data. SSD is mainly used on portable laptops and therefore does not usually hold sensitive data like would be on a tape, server or Network Attached Storage (NAS).
Interviewer: Some people crushing their hard drives or even throwing them into lakes so people can’t get hold of the data on them. Are these extreme measures necessary?
Richard: Obviously these methods will damage the media to some extent but data can still potentially be recovered. Degaussing is an invisible process and people cannot see it has been done unlike crushing. Customers must test the process if they have their doubts but once they see the results through testing they realise it is the best solution.
Interviewer: What advice would you give to people using and storing data for the long term?
Richard: Use new tape for long term storage and manage the media with software like TapeTrack to ensure the correct tapes are held on and offsite. Once the data is no longer required the media holding the data should be degaussed to ensure the data does not get into the wrong hands. After a large amount of use or long storage period people should copy the data to the latest generation of new media. Please see the manufacturer’s recommendations for this. Always use new tapes for any long term storage and ensure the tapes you are buying are new and not re-certified. Re-certified tapes have been used by others are not reliable for any data storage due to degradation by past wear and age. Always test the data you have backed up and archived to ensure you can restore. There are too many stories from the past about data backed up and when they went to restore there was nothing there!
Interviewer: Is any particular media better or worse for data storage and retention in your view?
Richard: Yes, tape is by far the best medium for storing data over medium to long term or for disaster recovery purposes. Hard drives are great for fast online storage of data but as soon as it is rarely accessed, (archive) or a copy needs to be made for disaster recovery purposes, tape is the way to go on price and reliability. Hard drives have too many failures and are too expensive over the longer term for archive and DR. For short term data and online data, hard drives are the way to go, but not when the data is being used for disaster recovery as they do not travel well (to offsite storage) and are therefore used onsite. Disaster recovery is preparing to recover data when your main site is lost or un-useable and thus they are unsuitable. Tapes by comparison are cheaper, reliable and most importantly portable so they can be taken to a safe offsite location. Some large organisations use duplicate data centres but to ensure they can recover over the long term they need offsite tape backup as well.