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Postgraduate · Chapter 9 · English

Chapter 9 — Recovery and continuity

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Chapter 9 — Recovery and continuity

Lesson map

Lesson 09 published. Map, example, EX041.

flowchart TD
  N0["Learning outcomes"]
  N1["9.1 Targets"]
  N2["9.2 Rebuilds"]
  N3["9.3 Testing"]
  N4["9.4 Ransomware readiness"]
  N5["Mapping dependencies"]
  N6["Communication during outages"]
  N7["Recovery for exception devices"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7
  N7 --> EX["Worked example"]
  EX --> Q["Exercise EX041"]

Logical drawing

flowchart LR
  N0["Learning outcomes"]
  N1["9.1 Targets"]
  N2["9.2 Rebuilds"]
  N3["9.3 Testing"]
  N4["9.4 Ransomware readiness"]
  N5["Mapping dependencies"]
  N6["Communication during outages"]
  N7["Recovery for exception devices"]
  N0 --> N1 --> N2 --> N3 --> N4 --> N5 --> N6 --> N7 --> Q["EX041"]

[Learning outcomes]
    |
    v
[9.1 Targets]
    |
    v
[9.2 Rebuilds]
    |
    v
[9.3 Testing]
    |
    v
[9.4 Ransomware readiness]
    |
    v
[Mapping dependencies]
    |
    v
[Communication during outages]
    |
    v
[Recovery for exception devices]
    |
    v
[Worked example] --> [Exercise EX041]

Learning outcomes

You will (1) define recovery targets; (2) test restores; (3) plan for a failed workstation.

9.1 Targets

The operations manager sets targets: a failed reception PC replaced within two hours from a pre-built spare; imaging server restored within one day. Targets come from the business, not the supplier, because the operations manager knows how long a clinic can work without a PC or images. A reception PC can be replaced quickly because desktops are standard. The imaging server takes longer because it holds images and vendor software. Priya records each target with the reason given, and the targets become the measure for recovery tests. Each clinic keeps one pre-built spare desktop for this purpose.

9.2 Rebuilds

Supported desktops are rebuilt from a standard image and management enrolment. Imaging PCs need vendor steps, so Priya documents them with the vendor. A standard image means a failed desktop can be replaced with a working one that already has the baseline settings and management. Imaging PCs are different: their software, licences and capture cards must be installed by the vendor or following its steps. Priya writes those steps down with the vendor's help, including what must be backed up beforehand, so the clinic is not dependent on one engineer's memory. The rebuild document is stored with the exception register, since the same imaging PCs appear in both.

9.3 Testing

A restore test of the image server on spare hardware takes seven hours, within the target, and reveals a missing licence file, now added to backups. Testing on spare hardware shows whether the restore works when it is needed, not just whether backups exist. The missing licence file would have stopped the server working after a real failure. Priya records the test date, duration, problems found and fixes made, and the operations manager agrees to repeat the test each year, as well as after any major change to the imaging server or its vendor software.

9.4 Ransomware readiness

One backup copy is offline. Isolated imaging segments limit spread. An offline copy cannot be encrypted by malware that reaches the network, so it remains available for recovery. Priya checks with the supplier how often the offline copy is updated and where it is kept. The isolated imaging segment helps in a different way: unsupported imaging PCs cannot reach most other machines, so ransomware that starts at reception has fewer paths to them. Restoring from the offline copy is part of the yearly recovery test. Priya records both measures in the recovery plan, so they are reviewed each year.

Mapping dependencies

Recovery needs to know what depends on what. The practice management client needs the central database; imaging PCs need the image server and the licence server; reception needs printers and card readers. Priya draws a simple dependency list for each clinic, so that during an outage staff restore things in the right order rather than rebooting everything at once.

She also identifies manual fallbacks: printed day lists so clinics can still see patients if the schedule is unavailable, and a paper form for treatment notes to be entered later. These fallbacks are tested once a year in a quiet session.

Communication during outages

Outages create a second problem besides the technical one: uncertainty. Clinic managers phone the supplier repeatedly, staff improvise workarounds and patients are told different things at each site. Priya prepares a short message template that the supplier sends to all clinic managers when a shared system fails. It states what is affected, what staff should do meanwhile, such as using the printed day lists, and when the next update will arrive even if nothing has changed. Updates go out at fixed intervals, every hour during an outage. Having the template ready saves time, reduces calls to the supplier and keeps every clinic acting on the same information.

Recovery for exception devices

Machines on old operating systems are the hardest to rebuild, because installation media, drivers and licence keys are old and may no longer be downloadable. If an exception imaging PC fails, Kestrel could find that it cannot be restored at all. Priya asks the vendor to confirm in writing that a rebuild remains possible and what it requires. The installation media, capture card drivers and licence keys are copied and stored offline with the backups, and the rebuild steps are documented. A rebuild is tested on a spare machine once. This turns a fragile dependency into a known procedure until the machines are finally replaced.

Worked example

The spare-PC test at Mill clinic swaps a reception PC in 75 minutes.

Synthetic case. Figures are synthetic.

Errors and limits

Untested backups often lack something; the licence file shows why.

Exercises

Synthesis

Recovery plans earn trust only through tests.

Continue studying — chapter 09 of 12

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