dgraph-io/badger · error

ErrWindowsNotSupported

ErrWindowsNotSupported

Error message

Read-only mode is not supported on Windows

What it means

ErrWindowsNotSupported is returned when opt.ReadOnly is used on Windows, where read-only mode is not implemented. It surfaces from acquireDirectoryLock (dir_windows.go:62) during DB.Open, and some tests special-case it. Defined in errors.go.

Source

Thrown at errors.go:82

	// ErrManagedTxn is returned if the user tries to use an API which isn't
	// allowed due to external management of transactions, when using ManagedDB.
	ErrManagedTxn = stderrors.New(
		"Invalid API request. Not allowed to perform this action using ManagedDB")

	// ErrNamespaceMode is returned if the user tries to use an API which is allowed only when
	// NamespaceOffset is non-negative.
	ErrNamespaceMode = stderrors.New(
		"Invalid API request. Not allowed to perform this action when NamespaceMode is not set.")

	// ErrInvalidDump if a data dump made previously cannot be loaded into the database.
	ErrInvalidDump = stderrors.New("Data dump cannot be read")

	// ErrZeroBandwidth is returned if the user passes in zero bandwidth for sequence.
	ErrZeroBandwidth = stderrors.New("Bandwidth must be greater than zero")

	// ErrWindowsNotSupported is returned when opt.ReadOnly is used on Windows
	ErrWindowsNotSupported = stderrors.New("Read-only mode is not supported on Windows")

	// ErrPlan9NotSupported is returned when opt.ReadOnly is used on Plan 9
	ErrPlan9NotSupported = stderrors.New("Read-only mode is not supported on Plan 9")

	// ErrTruncateNeeded is returned when the value log gets corrupt, and requires truncation of
	// corrupt data to allow Badger to run properly.
	ErrTruncateNeeded = stderrors.New(
		"Log truncate required to run DB. This might result in data loss")

	// ErrBlockedWrites is returned if the user called DropAll. During the process of dropping all
	// data from Badger, we stop accepting new writes, by returning this error.
	ErrBlockedWrites = stderrors.New("Writes are blocked, possibly due to DropAll or Close")

	// ErrNilCallback is returned when subscriber's callback is nil.
	ErrNilCallback = stderrors.New("Callback cannot be nil")

	// ErrEncryptionKeyMismatch is returned when the storage key is not
	// matched with the key previously given.

View on GitHub (pinned to 2a001d466f)

Solutions

1. Disable ReadOnly on Windows and open the DB read-write
2. Move read-only workloads to Linux/Plan9-free environments
3. Gate the WithReadOnly option behind a runtime.GOOS check in your config code

Example fix

// before
opts = append(opts, badger.WithReadOnly(true))
db, err := badger.Open(opts...)
// after
if runtime.GOOS != "windows" {
	opts = append(opts, badger.WithReadOnly(true))
}
db, err := badger.Open(opts...)

if readOnly && runtime.GOOS == "windows" { return errors.New("ReadOnly unsupported on Windows") }

db, err := badger.Open(opts)
if errors.Is(err, ErrWindowsNotSupported) {
	// fall back to read-write mode or fail fast on Windows
}

When it happens

Trigger: Opening a DB with badger.WithReadOnly(true) on a Windows host; the check fires immediately in acquireDirectoryLock during Open.

Common situations: Cross-platform applications using ReadOnly on a dev machine running Windows; CI matrix including Windows; running a read-replica deployment on Windows hosts.

Related errors

• ErrPlan9NotSupported
• ErrReadOnlyTxn
• ErrTruncateNeeded
• ErrGCInReadOnlyMode
• Cannot use GetSequence in read-only mode.

AI-assisted analysis of dgraph-io/badger@2a001d466f (2026-09-05). Data as JSON: /api/errors/ab3abea7d2f63519. Report an issue: GitHub.