{"record":{"id":"1fc991448414207c","repo":"hyperledger/fabric","slug":"error-opening-block-file-writer-for-file-s","errorCode":null,"errorMessage":"error opening block file writer for file %s","messagePattern":"error opening block file writer for file (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"critical","filePath":"common/ledger/blkstorage/blockfile_rw.go","lineNumber":52,"sourceCode":"\t}\n\treturn nil\n}\n\nfunc (w *blockfileWriter) append(b []byte, sync bool) error {\n\t_, err := w.file.Write(b)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif sync {\n\t\treturn w.file.Sync()\n\t}\n\treturn nil\n}\n\nfunc (w *blockfileWriter) open() error {\n\tfile, err := os.OpenFile(w.filePath, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0o660)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error opening block file writer for file %s\", w.filePath)\n\t}\n\tif err := fileutil.SyncParentDir(w.filePath); err != nil {\n\t\treturn err\n\t}\n\tw.file = file\n\treturn nil\n}\n\nfunc (w *blockfileWriter) close() error {\n\treturn errors.WithStack(w.file.Close())\n}\n\n// //  READER ////\ntype blockfileReader struct {\n\tfile *os.File\n}\n\nfunc newBlockfileReader(filePath string) (*blockfileReader, error) {","sourceCodeStart":34,"sourceCodeEnd":70,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/common/ledger/blkstorage/blockfile_rw.go#L34-L70","documentation":"This error is produced by blockfileWriter.open() when os.OpenFile fails to open (or create) the ledger's block file with O_RDWR|O_APPEND|O_CREATE. The underlying OS error is wrapped, so the original cause (permission denied, no such directory, etc.) appears in the chain. It occurs while opening a block file for writing during ledger creation or block commit.","triggerScenarios":"Calling newBlockfileWriter followed by open() when the file path's parent directory does not exist, the process lacks write permission on the file/directory, the path is a directory, or the filesystem is read-only or full (device-specific failures).","commonSituations":"Misconfigured peer.fileSystemPath / ledger data location pointing to a nonexistent or unwritable directory; running the peer as a non-root user without ownership of /var/hyperledger/production; container volumes mounted read-only; disk-full or corrupted ledger directory.","solutions":["Check the wrapped cause in the error chain (e.g. 'permission denied', 'no such file or directory') and fix that specific OS condition.","Verify the ledger data directory (peer.fileSystemPath/ledgersData) exists and is writable by the peer process user: mkdir -p and chown the directory.","Confirm the volume/mount is not read-only and the disk is not full (df -h, mount options).","If the ledger state is corrupt/unrecoverable, back up and remove the affected ledgersData directory and let the peer recreate it."],"exampleFix":"// before: peer started with data dir owned by root, peer runs as nonroot\n// ERROR: error opening block file writer for file /var/hyperledger/production/ledgersData/chains/chains/mychannel/blockfile_000000\n// after (shell):\nmkdir -p /var/hyperledger/production/ledgersData\nchown -R peer:peer /var/hyperledger/production","handlingStrategy":"validation","validationCode":"// Go: check writability of the ledger data dir before starting/committing\nfunc ensureWritable(path string) error {\n\tif st, err := os.Stat(path); err != nil {\n\t\tif os.IsNotExist(err) {\n\t\t\treturn os.MkdirAll(path, 0o750)\n\t\t}\n\t\treturn err\n\t} else if !st.IsDir() {\n\t\treturn fmt.Errorf(\"%s is not a directory\", path)\n\t}\n\tf, err := os.CreateTemp(path, \".writetest*\")\n\tif err != nil {\n\t\treturn err\n\t}\n\tf.Close()\n\tos.Remove(f.Name())\n\treturn nil\n}","typeGuard":null,"tryCatchPattern":"// Go: unwrap the cause to branch on the OS error\nif err := writer.open(); err != nil {\n\tswitch {\n\tcase os.IsPermission(errors.Cause(err)):\n\t\t// fix ownership/mode or fail fast with a clear config message\n\tcase os.IsNotExist(errors.Cause(err)):\n\t\t// create the parent directory and retry once\n\tdefault:\n\t\treturn err\n\t}\n}","preventionTips":["Run the peer with a dedicated user that owns peer.fileSystemPath recursively.","Provision the data directory (and mount it read-write) before first start.","Monitor disk free space; full disks surface first at block-file open/append.","Never mount ledgersData read-only or share it across peers."],"tags":["filesystem","io","ledger","hyperledger-fabric"],"backgroundTag":"file-open-failed","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T05:18:18.240Z"}