FAQ for Wiping Mass Storage Device

  1. What should we pay attention to when we dispose IT equipment with storage devices or external storage devices or when we transfer them for recycle-use?
    It is not easy to say whether a storage device contains sensitive information or not. As a rule of thumb, when we dispose or transfer storage device for recycle use, we should make sure that all data contents stored inside are erased in such a way that they are unrecoverable.

  2. Is it safe to delete and purge all files or reformat the whole storage devices using standard means?
    Files deleted on hard disk or a disk format using standard means will leave behind traces of magnetic characteristics such that, with special tools, it is possible to recover deleted information.

  3. What is the meaning of “unrecoverable”? What should I do?
    There are at least two methods that can remove data permanently and are unrecoverable - by use of a degausser or by use of a hard disk wiping tool.

  4. What services are provided by Computing Services Centre (CSC) in data erasure?
    The Computing Services Centre (CSC) is currently providing two types of data erasure tools to support departments. These include hard disk degaussing and disk wiping equipment. The following is a brief description and comparison between these two methods. Users can choose the one that fits them most.

  5. HDD Degaussing HDD Wiping
    Principle of the method Destroying the magnetic patterns that record the data. Destroy the data by writing data patterns to the storage devices multiple times.
    Suitable for
    • Magnetic hard disks only.
    • Drives to be disposed of are not functioning.
    • Any kind connection (SATA, PATA, SCSI…etc.).
    • Both magnetic and non-magnetic (e.g. SSD hard disks) type of data storage.
    • Recycle use of hard disks
    NOT suitable for
    • Drives larger than 500GB due to the existing equipment’s limit.
    • Non-magnetic storage devices such as SSD hard disk and flash drives
    • Connection type other than SATA and PATA, that is, SCSI drives are not support
    • Drives already found malfunctioning.
    Recycling No. Hard disks once erased by this method CANNOT be reused since the factory setting of the hard disk is also destroyed in the process. Yes. Storage devices normally can be reused as this method just overwrites the drives with randomized data pattern.
    Time required Very short required and does not depend on the hard disks. Normally less than 10 seconds per disk. The time is only required in charging up the equipment. Very long time required but depends on the size and speed of the storage device. (e.g. 500GB magnetic drive will require more than 3 hours to complete).
    Where to obtain the service? A degausser can be loaned to department from CSC Workshop in YEUNG-Y2518 (see below on how to obtain the service). One wiper machine can be loaned to department from CSC Workshop in YEUNG-Y2518 (see below on how to obtain the service). Alternatively, staff can self-help themselves and use another wiper machine located in CSC Teaching Studio Area (see below on how to obtain the service).
  6. What is the procedure to apply for the data removal services from CSC?
    To use the wiper machine in CSC Teaching Studio Area, users can reserve it through the CSC Booking System which can be found in the Portal. To borrow a storage removal tool, staff can apply through the departmental DNA to raise a CSC online Work Request. CSC usually can provide assistance and consultation to users, however, the actual operation of the machines have to be done by users themselves.

  7. Can I get back my data from the storage device after performing data erasure?
  8. One of the very important reminder is that, data after removed by one of the above ways, users can no longer able to get it back by any mean. Therefore, the CSC colleague who handles the request will ask users to sign a declaration form before to ensure users are clearly agreed with the consequence of data removal.

  9. Is there any outside service provider recommended for wiping service?
  10. Yes. As some wiping services are not available from CSC e.g. wiping smart phones data, a standing order agreement was made with an outside service provider (a recommended one for departments to consider) to offer a complete solution. In this agreement, users can choose between wiping* and shredding** services. In the shredding service, heavy-duty equipment is employed to cut devices into small broken pieces. The following table shows the prices of different options. This order is valid until March 2020.

    Unit Price (HK$) Unit Price (HK$)
      Carry-in by User Pick-up by Supplier
    Data Wiping Service for    
    Smart Phone 100 200
    Tablet 100 200
    USB Thumb Drive 100 200
    SSD Hard Disk 100 200
    Data Shredding Service    
    Smart Phone 50 150
    Tablet 100 200
    USB Thumb Drive 50 150
    SSD Hard Disk 50 150

    If you want more information, please contact the CSC Help Desk for more information.

    * Wiping is a method which overwrites the existing data in a storage media with dummy text so as to clear all existing data. Wiping is suitable for media which is working and writable, and is intended for reuse.

    **Shredding is a method which physically breaks a storage media into pieces. This is for media that is not intended for reuse.