Shared drive went read-only
10 or more people were affected for an hour or more. How severity is set
- Started
- 2026-03-10 08:40 EDT
- Noticed
- 2026-03-10 09:15 EDT
- Back to normal
- 2026-03-10 12:20 EDT
- Time to notice
- 35 min
- Time to fix
- 3 h 5 min
- Total
- 3 h 40 min
01 What happened
A made-up 12-person design studio. The office file server ran out of disk space overnight, so the shared drive turned read-only. Nobody could save work from 08:40 until 12:20.
Old project exports had filled the disk, and the backup job kept failing on the full disk without anyone seeing the warning.
02 Impact and cost
- People affected
- 12
- Customers affected
- No
- Data
- Some lost, all recovered
- Private data exposed
- No
Estimated cost$1,720
| People time (12 × $35/h × 3 h 40 min) | $1,540 |
|---|---|
| Lost sales | $0 |
| Outside help | $180 |
| Parts and replacements | $0 |
03 Timeline
- Note
Nightly backup fails: "no space left on device" (email warning lands in a shared inbox nobody reads)
- Note
First failed save in the design app (seen later in the server log)
- Noticed
Two designers report "file is read-only" errors to the office manager
- Told
Office manager tells the team to save work to their own laptops for now
- Did
IT contractor called; finds the disk 100% full
- Did
Old exports moved to an external drive; 180 GB freed
- Fixed
Shared drive writable again; laptop copies moved back
04 Why it happened
- Why 1
Why could nobody save? The shared drive turned read-only.
- Why 2
Why? The server disk was full.
- Why 3
Why? Years of project exports were kept on the same disk as live work.
- Why 4
Why was nobody warned? The disk and backup warnings went to an inbox nobody reads.
- Why 5
Why? The warning address was set up by a former employee and never changed.
Root cause
Disk space was never watched by anyone: the only warnings went to an unread inbox, and old exports shared a disk with live work.
Contributing factors
- Nothing alerted us; a person noticed
- An alert fired but was missed or muted
- Ran out of disk, memory or capacity
- Nobody clearly owned it
05 What went well
The office manager moved everyone to local saves within 15 minutes, so no work was lost.
What was hard
Nobody knew which files were safe to move, so freeing space took almost two hours.
06 Action items
| Status | Type | Action | Owner | Due |
|---|---|---|---|---|
| Done | Detect | Send disk and backup warnings to the office manager and the IT contractor | IT contractor | 2026-03-13 |
| Open | Prevent | Move finished projects to the archive drive every quarter | Studio lead | 2026-04-01 |
| Open | Detect | Alert at 80% disk use, not 100% | IT contractor | 2026-03-20 |
| Open | Respond | Write a one-page "server is full" checklist | Office manager | 2026-03-27 |