diff --git a/mayastor/src/bdev/mod.rs b/mayastor/src/bdev/mod.rs
index 9e5d77078..efa5a785e 100644
--- a/mayastor/src/bdev/mod.rs
+++ b/mayastor/src/bdev/mod.rs
@@ -21,7 +21,12 @@ pub use nexus::{
     },
     nexus_persistence::{ChildInfo, NexusInfo},
 };
-pub use nvmx::nvme_io_ctx_pool_init;
+pub use nvmx::{
+    nvme_io_ctx_pool_init,
+    NvmeController,
+    NvmeControllerState,
+    NVME_CONTROLLERS,
+};
 
 mod aio;
 pub(crate) mod dev;
@@ -33,7 +38,7 @@ pub(crate) mod nexus;
 mod null;
 mod nvme;
 mod nvmf;
-mod nvmx;
+pub(crate) mod nvmx;
 mod uring;
 pub mod util;
 
diff --git a/mayastor/src/bdev/nvmx/mod.rs b/mayastor/src/bdev/nvmx/mod.rs
index 7779ef473..c4bd90bde 100755
--- a/mayastor/src/bdev/nvmx/mod.rs
+++ b/mayastor/src/bdev/nvmx/mod.rs
@@ -28,7 +28,7 @@ pub mod utils;
 
 #[derive(Debug)]
 #[allow(clippy::upper_case_acronyms)]
-pub(crate) struct NVMeCtlrList<'a> {
+pub struct NVMeCtlrList<'a> {
     entries: RwLock<HashMap<String, Arc<Mutex<NvmeController<'a>>>>>,
 }
 
@@ -90,6 +90,16 @@ impl<'a> NVMeCtlrList<'a> {
         let mut entries = self.write_lock();
         entries.insert(cid, ctl);
     }
+
+    /// Get the names of all available NVMe controllers.
+    pub fn controllers(&self) -> Vec<String> {
+        let entries = self.read_lock();
+        entries
+            .keys()
+            .map(|k| k.to_string())
+            .filter(|k| k.contains("nqn")) // Filter out CIDs
+            .collect::<Vec<_>>()
+    }
 }
 
 impl<'a> Default for NVMeCtlrList<'a> {
@@ -102,7 +112,8 @@ impl<'a> Default for NVMeCtlrList<'a> {
     }
 }
 
-static NVME_CONTROLLERS: Lazy<NVMeCtlrList> = Lazy::new(NVMeCtlrList::default);
+pub static NVME_CONTROLLERS: Lazy<NVMeCtlrList> =
+    Lazy::new(NVMeCtlrList::default);
 
 pub fn nvme_bdev_running_config() -> &'static NvmeBdevOpts {
     &Config::get().nvme_bdev_opts
diff --git a/mayastor/src/bin/mayastor-client/controller_cli.rs b/mayastor/src/bin/mayastor-client/controller_cli.rs
new file mode 100755
index 000000000..df330e18b
--- /dev/null
+++ b/mayastor/src/bin/mayastor-client/controller_cli.rs
@@ -0,0 +1,95 @@
+//!
+//! methods to interact with NVMe controllers
+
+use super::context::Context;
+use crate::{context::OutputFormat, GrpcStatus};
+use ::rpc::mayastor as rpc;
+use clap::{App, AppSettings, ArgMatches, SubCommand};
+use colored_json::ToColoredJson;
+use snafu::ResultExt;
+use tonic::Status;
+
+pub fn subcommands<'a, 'b>() -> App<'a, 'b> {
+    let list =
+        SubCommand::with_name("list").about("List existing NVMe controllers");
+
+    SubCommand::with_name("controller")
+        .settings(&[
+            AppSettings::SubcommandRequiredElseHelp,
+            AppSettings::ColoredHelp,
+            AppSettings::ColorAlways,
+        ])
+        .about("NVMe controllers")
+        .subcommand(list)
+}
+
+pub async fn handler(
+    ctx: Context,
+    matches: &ArgMatches<'_>,
+) -> crate::Result<()> {
+    match matches.subcommand() {
+        ("list", Some(args)) => list_controllers(ctx, args).await,
+        (cmd, _) => {
+            Err(Status::not_found(format!("command {} does not exist", cmd)))
+                .context(GrpcStatus)
+        }
+    }
+}
+
+fn controller_state_to_str(idx: i32) -> String {
+    match rpc::NvmeControllerState::from_i32(idx).unwrap() {
+        rpc::NvmeControllerState::New => "new",
+        rpc::NvmeControllerState::Initializing => "init",
+        rpc::NvmeControllerState::Running => "running",
+        rpc::NvmeControllerState::Faulted => "faulted",
+        rpc::NvmeControllerState::Unconfiguring => "unconfiguring",
+        rpc::NvmeControllerState::Unconfigured => "unconfigured",
+    }
+    .to_string()
+}
+
+async fn list_controllers(
+    mut ctx: Context,
+    _matches: &ArgMatches<'_>,
+) -> crate::Result<()> {
+    let response = ctx
+        .client
+        .list_nvme_controllers(rpc::Null {})
+        .await
+        .context(GrpcStatus)?;
+
+    match ctx.output {
+        OutputFormat::Json => {
+            println!(
+                "{}",
+                serde_json::to_string_pretty(&response.get_ref())
+                    .unwrap()
+                    .to_colored_json_auto()
+                    .unwrap()
+            );
+        }
+        OutputFormat::Default => {
+            let controllers = &response.get_ref().controllers;
+            if controllers.is_empty() {
+                ctx.v1("No NVMe controllers found");
+                return Ok(());
+            }
+
+            let table = controllers
+                .iter()
+                .map(|c| {
+                    let size = c.size.to_string();
+                    let blk_size = c.blk_size.to_string();
+                    let state = controller_state_to_str(c.state);
+
+                    vec![c.name.clone(), size, state, blk_size]
+                })
+                .collect();
+
+            let hdr = vec!["NAMEs", "SIZE", "STATE", "BLKSIZE"];
+            ctx.print_list(hdr, table);
+        }
+    }
+
+    Ok(())
+}
diff --git a/mayastor/src/bin/mayastor-client/main.rs b/mayastor/src/bin/mayastor-client/main.rs
index 5a1d67c6e..eb21b44d9 100644
--- a/mayastor/src/bin/mayastor-client/main.rs
+++ b/mayastor/src/bin/mayastor-client/main.rs
@@ -12,6 +12,7 @@ use ::rpc::mayastor::{
 
 mod bdev_cli;
 mod context;
+mod controller_cli;
 mod device_cli;
 mod jsonrpc_cli;
 mod nexus_child_cli;
@@ -108,6 +109,7 @@ async fn main() -> crate::Result<()> {
         .subcommand(rebuild_cli::subcommands())
         .subcommand(snapshot_cli::subcommands())
         .subcommand(jsonrpc_cli::subcommands())
+        .subcommand(controller_cli::subcommands())
         .get_matches();
 
     let ctx = Context::new(&matches).await.context(ContextError)?;
@@ -121,6 +123,7 @@ async fn main() -> crate::Result<()> {
         ("replica", Some(args)) => replica_cli::handler(ctx, args).await,
         ("rebuild", Some(args)) => rebuild_cli::handler(ctx, args).await,
         ("snapshot", Some(args)) => snapshot_cli::handler(ctx, args).await,
+        ("controller", Some(args)) => controller_cli::handler(ctx, args).await,
         ("jsonrpc", Some(args)) => jsonrpc_cli::json_rpc_call(ctx, args).await,
         _ => panic!("Command not found"),
     };
diff --git a/mayastor/src/grpc/controller_grpc.rs b/mayastor/src/grpc/controller_grpc.rs
new file mode 100755
index 000000000..0867958ae
--- /dev/null
+++ b/mayastor/src/grpc/controller_grpc.rs
@@ -0,0 +1,72 @@
+use crate::{
+    bdev::{
+        nexus::nexus_bdev,
+        NvmeController,
+        NvmeControllerState,
+        NVME_CONTROLLERS,
+    },
+    grpc::{rpc_submit, GrpcResult},
+};
+
+use ::rpc::mayastor as rpc;
+use std::convert::From;
+use tonic::{Response, Status};
+
+impl<'a> NvmeController<'a> {
+    fn to_grpc(&self) -> rpc::NvmeController {
+        let (size, blk_size) = self
+            .namespace()
+            .map_or((0, 0), |ns| (ns.size_in_bytes(), ns.block_len() as u32));
+
+        rpc::NvmeController {
+            name: self.name.to_string(),
+            state: rpc::NvmeControllerState::from(self.get_state()) as i32,
+            size,
+            blk_size,
+        }
+    }
+}
+
+impl From<NvmeControllerState> for rpc::NvmeControllerState {
+    fn from(state: NvmeControllerState) -> Self {
+        match state {
+            NvmeControllerState::New => rpc::NvmeControllerState::New,
+            NvmeControllerState::Initializing => {
+                rpc::NvmeControllerState::Initializing
+            }
+            NvmeControllerState::Running => rpc::NvmeControllerState::Running,
+            NvmeControllerState::Faulted(_) => {
+                rpc::NvmeControllerState::Faulted
+            }
+            NvmeControllerState::Unconfiguring => {
+                rpc::NvmeControllerState::Unconfiguring
+            }
+            NvmeControllerState::Unconfigured => {
+                rpc::NvmeControllerState::Unconfigured
+            }
+        }
+    }
+}
+
+pub async fn list_controllers() -> GrpcResult<rpc::ListNvmeControllersReply> {
+    let rx = rpc_submit::<_, _, nexus_bdev::Error>(async move {
+        let controllers = NVME_CONTROLLERS
+            .controllers()
+            .iter()
+            .filter_map(|n| {
+                NVME_CONTROLLERS
+                    .lookup_by_name(n)
+                    .map(|c| c.lock().to_grpc())
+            })
+            .collect::<Vec<_>>();
+
+        Ok(rpc::ListNvmeControllersReply {
+            controllers,
+        })
+    })?;
+
+    rx.await
+        .map_err(|_| Status::cancelled("cancelled"))?
+        .map_err(Status::from)
+        .map(Response::new)
+}
diff --git a/mayastor/src/grpc/mayastor_grpc.rs b/mayastor/src/grpc/mayastor_grpc.rs
index d9ed8ed8e..9a4697717 100644
--- a/mayastor/src/grpc/mayastor_grpc.rs
+++ b/mayastor/src/grpc/mayastor_grpc.rs
@@ -2,7 +2,7 @@
 //!
 //! The Mayastor gRPC methods serve as a higher abstraction for provisioning
 //! replicas and targets to be used with CSI.
-//!
+//
 //! We want to keep the code here to a minimal, for example grpc/pool.rs
 //! contains all the conversions and mappings etc to whatever interface from a
 //! grpc perspective we provide. Also, by doing his, we can test the methods
@@ -16,6 +16,7 @@ use crate::{
     },
     core::{Bdev, BlockDeviceIoStats, CoreError, Protocol, Share},
     grpc::{
+        controller_grpc::list_controllers,
         nexus_grpc::{
             nexus_add_child,
             nexus_destroy,
@@ -152,6 +153,7 @@ impl From<Lvol> for Replica {
         }
     }
 }
+
 #[tonic::async_trait]
 impl mayastor_server::Mayastor for MayastorSvc {
     async fn create_pool(
@@ -904,4 +906,11 @@ impl mayastor_server::Mayastor for MayastorSvc {
         trace!("{:?}", reply);
         Ok(Response::new(reply))
     }
+
+    async fn list_nvme_controllers(
+        &self,
+        _request: Request<Null>,
+    ) -> GrpcResult<ListNvmeControllersReply> {
+        list_controllers().await
+    }
 }
diff --git a/mayastor/src/grpc/mod.rs b/mayastor/src/grpc/mod.rs
index 024d93b01..c57353bba 100644
--- a/mayastor/src/grpc/mod.rs
+++ b/mayastor/src/grpc/mod.rs
@@ -35,6 +35,7 @@ impl From<CoreError> for tonic::Status {
     }
 }
 mod bdev_grpc;
+mod controller_grpc;
 mod json_grpc;
 mod mayastor_grpc;
 mod nexus_grpc;
diff --git a/rpc/proto/mayastor.proto b/rpc/proto/mayastor.proto
index 612dd15cd..b3aa08579 100644
--- a/rpc/proto/mayastor.proto
+++ b/rpc/proto/mayastor.proto
@@ -75,6 +75,9 @@ service Mayastor {
 
   // Obtain resource usage statistics for the current process
   rpc GetResourceUsage (Null) returns (GetResourceUsageReply) {}
+
+  // NVMe controllers
+  rpc ListNvmeControllers (Null) returns (ListNvmeControllersReply) {}
 }
 
 // Means no arguments or no return value.
@@ -470,6 +473,26 @@ message CreateReply {
   string name = 1;
 }
 
+enum NvmeControllerState {
+  NEW = 0;
+  INITIALIZING = 1;
+  RUNNING = 2;
+  FAULTED = 3;
+  UNCONFIGURING = 4;
+  UNCONFIGURED = 5;
+}
+
+message NvmeController {
+  string name = 1;               // NVMe controller name
+  NvmeControllerState state = 2; // Current state of the NVMe controller
+  uint64 size = 3;               // Size of the controller's namespace (0 if no namespace attached).
+  uint32 blk_size = 4;           // Block size of the namespace (0 if no namespace attached).
+}
+
+message ListNvmeControllersReply {
+  repeated NvmeController controllers = 1;
+}
+
 // SPDK json-rpc proxy service
 
 service JsonRpc {
diff --git a/test/grpc/test_cli.js b/test/grpc/test_cli.js
index f2720b957..44d599f27 100644
--- a/test/grpc/test_cli.js
+++ b/test/grpc/test_cli.js
@@ -177,6 +177,26 @@ describe('mayastor-client', function () {
             ]
           }
         },
+        {
+          method: 'ListNvmeControllers',
+          input: {},
+          output: {
+            controllers: [
+              {
+                name: '10.0.0.4:8420/nqn.2019-05.io.openebs:null1n1',
+                state: 2,
+                size: 100 * (1024 * 1024),
+                blkSize: 4096
+              },
+              {
+                name: '10.0.0.5:8420/nqn.2019-05.io.openebs:null1n1',
+                state: 3,
+                size: 100 * (1024 * 1024),
+                blkSize: 4096
+              }
+            ]
+          }
+        },
         {
           method: 'DestroyNexus',
           input: {
@@ -495,6 +515,42 @@ describe('mayastor-client', function () {
       });
     });
 
+    it('should list nvme controllers for nexus children', function (done) {
+      const cmd = util.format('%s -q controller list', EGRESS_CMD);
+
+      exec(cmd, (err, stdout, stderr) => {
+        const controllers = [];
+        if (err) { return done(err); }
+        assert.isEmpty(stderr);
+
+        stdout.split('\n').forEach((line) => {
+          const parts = line.trim().split(' ').filter((s) => s.length !== 0);
+          if (parts.length <= 1) { return; }
+
+          controllers.push({
+            name: parts[0],
+            size: parts[1],
+            state: parts[2],
+            blk_size: parts[3]
+          });
+        });
+
+        assert.lengthOf(controllers, 2);
+
+        assert.equal(controllers[0].name, '10.0.0.4:8420/nqn.2019-05.io.openebs:null1n1');
+        assert.equal(controllers[0].size, '104857600');
+        assert.equal(controllers[0].state, 'running');
+        assert.equal(controllers[0].blk_size, '4096');
+
+        assert.equal(controllers[1].name, '10.0.0.5:8420/nqn.2019-05.io.openebs:null1n1');
+        assert.equal(controllers[1].size, '104857600');
+        assert.equal(controllers[1].state, 'faulted');
+        assert.equal(controllers[1].blk_size, '4096');
+
+        done();
+      });
+    });
+
     it('should list nexus children', function (done) {
       const cmd = util.format('%s -q nexus children %s', EGRESS_CMD, UUID1);