Help & Support

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 AC1-Y25118 (see below on how to obtain the service). One wiper machine can be loaned to department from CSC Workshop in AC1-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 ePortal. 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.

csc@cityu.edu.hk