diff --git a/Cargo.lock b/Cargo.lock
index f41d5fc..29f7ecd 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -29,6 +29,12 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "boxfnonce"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5988cb1d626264ac94100be357308f29ff7cbdd3b36bda27f450a4ee3f713426"
+
 [[package]]
 name = "bumpalo"
 version = "3.9.1"
@@ -66,6 +72,16 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "daemonize"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70c24513e34f53b640819f0ac9f705b673fcf4006d7aab8778bee72ebfc89815"
+dependencies = [
+ "boxfnonce",
+ "libc",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.3"
@@ -148,6 +164,7 @@ dependencies = [
  "anyhow",
  "kaminari 0.9.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "realm_io",
+ "realm_syscall",
  "tokio",
 ]
 
@@ -316,14 +333,25 @@ dependencies = [
 
 [[package]]
 name = "realm_io"
-version = "0.3.2"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6acf08c84d59f96c48b46d5e8bce63d311469a9e43ee971a246344f6ad4d081b"
+checksum = "765e31d68e3708d65d98c7f66023c3715711614553ec279499ef5c1a2544e256"
 dependencies = [
  "libc",
  "tokio",
 ]
 
+[[package]]
+name = "realm_syscall"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd1c4fd7ea55ef4a956906e911f99250f51154f25f699aca154d9cefe94a7c9a"
+dependencies = [
+ "daemonize",
+ "libc",
+ "socket2",
+]
+
 [[package]]
 name = "ring"
 version = "0.16.20"
diff --git a/cmd/Cargo.toml b/cmd/Cargo.toml
index ec2acc5..91829f4 100644
--- a/cmd/Cargo.toml
+++ b/cmd/Cargo.toml
@@ -10,7 +10,8 @@ license = "GPL-3.0"
 
 [dependencies]
 anyhow = "1"
-realm_io = "0.3.2"
+realm_io = "0.3.4"
+realm_syscall = "0.1.6"
 kaminari = { version = "0.9.2", features = ["ws"] }
 tokio = { version = "1.9", features = ["rt", "net", "macros"] }
 
diff --git a/cmd/src/client.rs b/cmd/src/client.rs
index f8de4a8..44f9ac3 100644
--- a/cmd/src/client.rs
+++ b/cmd/src/client.rs
@@ -9,7 +9,7 @@ use kaminari::trick::Ref;
 use kaminari::AsyncConnect;
 use kaminari::nop::NopConnect;
 use kaminari::ws::WsConnect;
-#[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+#[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
 use kaminari::tls::TlsConnect;
 
 use kaminari_cmd::{Endpoint, parse_cmd, parse_env};
@@ -19,7 +19,7 @@ async fn main() -> Result<()> {
     let (Endpoint { local, remote }, options) = parse_env().or_else(|_| parse_cmd())?;
 
     let ws = opt::get_ws_conf(&options);
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     let tls = opt::get_tls_client_conf(&options);
 
     eprintln!("listen: {}", &local);
@@ -29,13 +29,16 @@ async fn main() -> Result<()> {
         eprintln!("ws: {}", ws)
     }
 
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     if let Some(tls) = &tls {
         eprintln!("tls: {}", &tls);
     }
 
     let lis = TcpListener::bind(local).await?;
 
+    #[cfg(all(unix, not(target_os = "android")))]
+    let _ = realm_syscall::bump_nofile_limit();
+
     macro_rules! run {
         ($cc: expr) => {
             println!("connect: {}", $cc.as_ref());
@@ -75,7 +78,7 @@ async fn main() -> Result<()> {
         }
     }
 
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     match (ws, tls) {
         (None, None) => {
             let client = NopConnect {};
@@ -95,7 +98,7 @@ async fn main() -> Result<()> {
         }
     };
 
-    #[cfg(not(any(feature="tls-rustls", feature="tls-openssl")))]
+    #[cfg(not(any(feature = "tls-rustls", feature = "tls-openssl")))]
     if let Some(ws) = ws {
         let client = WsConnect::new(NopConnect {}, ws);
         run_ws_each!(client);
diff --git a/cmd/src/server.rs b/cmd/src/server.rs
index b18206c..93d0d62 100644
--- a/cmd/src/server.rs
+++ b/cmd/src/server.rs
@@ -9,7 +9,7 @@ use kaminari::trick::Ref;
 use kaminari::AsyncAccept;
 use kaminari::nop::NopAccept;
 use kaminari::ws::WsAccept;
-#[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+#[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
 use kaminari::tls::TlsAccept;
 
 use kaminari_cmd::{Endpoint, parse_cmd, parse_env};
@@ -30,7 +30,7 @@ async fn main() -> Result<()> {
 
     let ws = opt::get_ws_conf(&options);
 
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     let tls = opt::get_tls_server_conf(&options);
 
     eprintln!("listen: {}", &local);
@@ -40,13 +40,16 @@ async fn main() -> Result<()> {
         eprintln!("ws: {}", ws)
     }
 
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     if let Some(tls) = &tls {
         eprintln!("tls: {}", &tls);
     }
 
     let lis = TcpListener::bind(local).await?;
 
+    #[cfg(all(unix, not(target_os = "android")))]
+    let _ = realm_syscall::bump_nofile_limit();
+
     macro_rules! run {
         ($ac: expr) => {
             println!("accept: {}", $ac.as_ref());
@@ -64,7 +67,7 @@ async fn main() -> Result<()> {
         };
     }
 
-    #[cfg(any(feature="tls-rustls", feature="tls-openssl"))]
+    #[cfg(any(feature = "tls-rustls", feature = "tls-openssl"))]
     match (ws, tls) {
         (None, None) => {
             let server = NopAccept {};
@@ -84,7 +87,7 @@ async fn main() -> Result<()> {
         }
     };
 
-    #[cfg(not(any(feature="tls-rustls", feature="tls-openssl")))]
+    #[cfg(not(any(feature = "tls-rustls", feature = "tls-openssl")))]
     if let Some(ws) = ws {
         let server = WsAccept::new(NopAccept {}, ws);
         run!(Ref::new(&server));