message: nydusd: remove uncommonly used short options
  Remove uncommonly used short options.
diff: @@ -229,7 +229,6 @@ fn append_fs_options(app: Command) -> Command {
  .arg(
  Arg::new("prefetch-files")
  .long("prefetch-files")
  - .short('P')
  .help("List of files/directories to prefetch")
  .required(false)
  .requires("bootstrap")
  @@ -264,7 +263,6 @@ fn append_fuse_options(app: Command) -> Command {
  .arg(
  Arg::new("threads")
  .long("thread-num")
  - .short('T')
  .default_value("4")
  .help("Number of worker threads to serve IO requests")
  .value_parser(thread_validator)
  @@ -273,7 +271,6 @@ fn append_fuse_options(app: Command) -> Command {
  .arg(
  Arg::new("writable")
  .long("writable")
  - .short('W')
  .action(ArgAction::SetTrue)
  .help("Mounts FUSE filesystem in rw mode"),
  )
  @@ -291,7 +288,6 @@ fn append_virtiofs_options(cmd: Command) -> Command {
  cmd.arg(
  Arg::new("hybrid-mode")
  .long("hybrid-mode")
  - .short('H')
  .help("Enables both `rafs` and `passthroughfs` modes")
  .action(ArgAction::SetFalse)
  .required(false),
  @@ -299,7 +295,6 @@ fn append_virtiofs_options(cmd: Command) -> Command {
  .arg(
  Arg::new("sock")
  .long("sock")
  - .short('v')
  .help("Vhost-user API socket")
  .required(false),
  )
  @@ -332,9 +327,7 @@ fn append_fscache_options(app: Command) -> Command {
  fn append_services_subcmd_options(cmd: Command) -> Command {
  let subcmd = Command::new("singleton")
  - .about(
  - "Run as a global daemon instance to service multiple blobcache/fscache/fuse services.",
  - )
  + .about("Run as a global daemon to host multiple blobcache/fscache/fuse/virtio-fs services")
  .arg(
  Arg::new("fscache")
  .long("fscache")
  @@ -380,7 +373,6 @@ fn prepare_commandline_options() -> Command {
  .arg(
  Arg::new("id")
  .long("id")
  - .short('I')
  .help("Service instance identifier")
  .required(false)
  .requires("supervisor")
  @@ -415,7 +407,6 @@ fn prepare_commandline_options() -> Command {
  .arg(
  Arg::new("rlimit-nofile")
  .long("rlimit-nofile")
  - .short('R')
  .default_value("1000000")
  .help("Set rlimit for maximum file descriptor number (0 leaves it unchanged)")
  .required(false)
  @@ -424,7 +415,6 @@ fn prepare_commandline_options() -> Command {
  .arg(
  Arg::new("supervisor")
  .long("supervisor")
  - .short('S')
  .help("Supervisor API socket")
  .required(false)
  .requires("id")
  @@ -433,7 +423,6 @@ fn prepare_commandline_options() -> Command {
  .arg(
  Arg::new("upgrade")
  .long("upgrade")
  - .short('U')
  .help("Starts daemon in upgrade mode")
  .action(ArgAction::SetTrue)
  .required(false)
  