{"record":{"id":"67247d847b4459f2","repo":"hashicorp/nomad","slug":"failed-to-create-allocation-directory-for-volume","errorCode":null,"errorMessage":"failed to create allocation directory for volume (%s): %v","messagePattern":"failed to create allocation directory for volume \\((.+?)\\): (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"client/pluginmanager/csimanager/volume.go","lineNumber":466,"sourceCode":"\tif err != nil {\n\t\treturn \"\", false, fmt.Errorf(\"mount point detection failed for volume (%s): %v\", vol.ID, err)\n\t}\n\n\treturn hostStagingPath, !isNotMount, nil\n}\n\n// ensureAllocDir attempts to create a directory for use when publishing a volume\n// and then validates that the path is not already a mount point (e.g when reattaching\n// to existing allocs).\n//\n// Returns whether the directory is a pre-existing mountpoint, the publish path,\n// and any errors that occurred.\nfunc (v *volumeManager) ensureAllocDir(vol *structs.CSIVolume, alloc *structs.Allocation, usage *UsageOptions) (string, bool, error) {\n\tallocPath := v.allocDirForVolume(v.mountRoot, vol.ID, alloc.ID)\n\n\t// Make the alloc path, owned by the Nomad User\n\tif err := os.MkdirAll(allocPath, 0700); err != nil && !os.IsExist(err) {\n\t\treturn \"\", false, fmt.Errorf(\"failed to create allocation directory for volume (%s): %v\", vol.ID, err)\n\t}\n\n\t// Validate that the target is not already a mount point\n\ttargetPath := v.targetForVolume(v.mountRoot, vol.ID, alloc.ID, usage)\n\n\tm := mount.New()\n\tisNotMount, err := m.IsNotAMountPoint(targetPath)\n\n\tswitch {\n\tcase errors.Is(err, os.ErrNotExist):\n\t\t// ignore; path does not exist and as such is not a mount\n\tcase err != nil:\n\t\treturn \"\", false, fmt.Errorf(\"mount point detection failed for volume (%s): %v\", vol.ID, err)\n\t}\n\n\treturn targetPath, !isNotMount, nil\n}\n","sourceCodeStart":448,"sourceCodeEnd":484,"githubUrl":"https://github.com/hashicorp/nomad/blob/482b49bf1aec006f089bcfc7e632d8f6ac303e5e/client/pluginmanager/csimanager/volume.go#L448-L484","documentation":"ensureAllocDir in Nomad's CSI volume manager creates the per-allocation directory (mode 0700) that a published volume is mounted into. If os.MkdirAll fails with any error other than 'already exists', publishVolume fails with this message wrapping the OS error.","triggerScenarios":"os.MkdirAll(allocPath, 0700) returns a non-IsExist error during publishVolume — e.g. the alloc dir path component is a file, the mount root is unwritable, disk full, or read-only filesystem.","commonSituations":"Nomad client data dir permissions broken after host migration/restore; alloc directory corrupted (file where directory expected); ENOSPC on the node; security policies (SELinux/AppArmor) blocking writes under the client data dir.","solutions":["Inspect the wrapped OS error and the alloc path on the host; remove/fix any non-directory file occupying the path","Correct ownership/permissions on the Nomad client data dir for the Nomad user","Free disk space or remount read-write if ENOSPC/EROFS is the cause","Restart the Nomad client after fixing the filesystem so the alloc dir is recreated"],"exampleFix":"// before (host)\nls -l /var/lib/nomad/client/<alloc_id>  # regular file\n// after (host)\nrm /var/lib/nomad/client/<alloc_id>\n# restart nomad client; alloc dir recreated with mode 0700","handlingStrategy":"validation","validationCode":"allocPath := filepath.Join(mountRoot, allocID)\nif fi, err := os.Stat(allocPath); err == nil && !fi.IsDir() {\n    return fmt.Errorf(\"alloc path %s is not a directory\", allocPath)\n}\nif err := unix.Access(mountRoot, unix.W_OK); err != nil {\n    return fmt.Errorf(\"mount root %s not writable: %v\", mountRoot, err)\n}","typeGuard":null,"tryCatchPattern":"path, published, err := vm.EnsureAllocDir(vol, alloc, usage)\nif err != nil {\n    return fmt.Errorf(\"alloc dir setup failed: %w\", err) // fix OS-level cause before retry\n}","preventionTips":["Keep the Nomad client data dir owned and writable by the Nomad user","Monitor node disk usage and filesystem health","Do not place regular files where alloc directories are created","Re-validate data dir integrity after crash recovery or host migration"],"tags":["csi","nomad","filesystem","mkdir","volume-publish"],"backgroundTag":"mkdir-permission-denied","analyzedSha":"482b49bf1aec006f089bcfc7e632d8f6ac303e5e","analyzedAt":"2026-09-04T07:54:14.808Z","contentChangedAt":"2026-09-04T07:54:14.808Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}