Merge #1587

1587: Feat: LVM as a pool backend r=tiagolobocastro a=tiagolobocastro

Add LVM as an experimental alternative backend to Mayastor:
1. it allows us to use a low latency single replica
local volume (app pinned to the same node)
2. robust backend for existing LVM users which may prefer it
3. combine local engines into mayastor

This differs from the existing lvm localpv as rather than importing
the existing VGs we create the LVM PV's and the LVM VG itself.
On destruction, if the VG has no non-mayastor LVs then we destroy it,
otherwise we leave it behind, untagged.

The existing pool/replica services are also refactored to support
adding other backends in the future as well.
This is achieved by implementing the service interface separately
and binding them at a higher level. This way it avoids mixing
the backend code, at least as much as possible.

Co-authored-by: Tiago Castro <tiagolobocastro@gmail.com>

Author: mayastor-bors

ci.nix

@@ -72,6 +72,7 @@ mkShell {
   SPDK_PATH = if nospdk then null else "${spdk}";
   FIO_SPDK = if nospdk then null else "${spdk}/fio/spdk_nvme";
   ETCD_BIN = "${etcd}/bin/etcd";
+  LVM_BINS = "${lvm2.bin}/bin";
 
   IO_ENGINE_DIR = if asan then "target/x86_64-unknown-linux-gnu/debug" else "target/debug";
 
@@ -102,6 +103,7 @@ mkShell {
     ${pkgs.lib.optionalString (!nospdk) "echo 'SPDK version    :' $(echo $SPDK_PATH | sed 's/.*libspdk-//g')"}
     ${pkgs.lib.optionalString (!nospdk) "echo 'SPDK path       :' $SPDK_PATH"}
     ${pkgs.lib.optionalString (!nospdk) "echo 'SPDK FIO plugin :' $FIO_SPDK"}
+    echo 'LVM path        :' $LVM_BINS
     ${pkgs.lib.optionalString (!norust) "echo 'Rust version    :' $(rustc --version 2> /dev/null || echo '${norustc_msg}')"}
     ${pkgs.lib.optionalString (!norust) "echo 'Rust path       :' $(which rustc 2> /dev/null || echo '${norustc_msg}')"}
     echo 'I/O engine dir  :' $IO_ENGINE_DIR

doc/lvm.md

@@ -0,0 +1,109 @@
+# LVM as an alternative backend to Mayastor (Experimental!)
+
+Mayastor, a cloud-native declarative data plane written in Rust, aims to abstract storage resources
+and their differences through the data plane.
+
+In this document, we’ll explore how to integrate Logical Volume Management (LVM) as an alternative
+backend for Mayastor pools.
+LVM, a mature and widely adopted storage management system in Linux environments, offers robustness
+and extensive features that can enhance Mayastor’s storage services.
+
+## Motivation
+
+LVM is a mature and widely adopted storage management system in Linux environments.
+While the SPDK Blobstore (LVS) has been a reliable option, integrating LVM as an alternative backend
+can captivate a broader audience due to its robustness and maturity, feature set,
+and community support make it an attractive choice for Mayastor users.
+By integrating LVM, we can also allow users to upgrade existing non-replicated LVM volumes
+(eg: lvm-localpv) seamlessly.
+
+## Goals
+
+Alternative Backend: Enable Mayastor to use LVM volume groups as an alternative backend for storage
+pools.
+Dynamic Volume Management: Leverage LVM’s volume management features (resizing, snapshots,
+thin provisioning) within Mayastor.
+Simplicity: Abstract LVM complexities from users while providing robust storage services.
+
+### Supporting Changes
+1. Pools
+
+   Mayastor pools represent devices supplying persistent backing storage.
+   Introduce a new pool type: LVM Pool.
+   Users can create new Mayastor pools with the LVM backend type.
+
+2. LVM Integration
+
+   Extend Mayastor to integrate with LVM.
+   Implement LVM-specific logic for pool and replica creation, replica resizing, and snapshot management.
+   Ensure seamless interaction between Mayastor and LVM.
+
+3. Replication (HA)
+
+   Extend Mayastor’s replication mechanisms to work with LVM-backed logical units.
+   In short, make LVM backed volumes highly available across nodes.
+
+4. Volume Management
+
+   Mayastor will expose LVM volume management features through its pool API.
+   Users can resize volumes online.
+   Snapshots are managed transparently.
+
+Features
+---
+
+- [x] Pool Operations
+  - [x] Create
+  - [x] Destroy
+  - [x] Import
+  - [x] List
+- [x] Replica Operations
+  - [x] Create
+  - [x] Destroy
+  - [x] Share/Unshare
+  - [x] Resize
+  - [x] List
+- [ ] Thin Provisioning
+- [ ] Snapshots
+- [ ] Clones
+- [ ] RAIDx
+
+### Limitation
+- Thin provisioning and snapshot support is not yet integrated
+- RAID is not yet integrated
+
+## Conclusion
+
+By integrating LVM with Mayastor, you can leverage the benefits of both technologies. LVM provides dynamic volume management,
+while Mayastor abstracts storage complexities, allowing you to focus on your applications.
+Happy storage provisioning! 🚀
+
+
+```mermaid
+graph TD;
+   subgraph Volume Group - VG
+      VG_1 --> LV_1["replica 1"]
+      VG_1 --> LV_2["replica 2"]
+      VG_2 --> LV_3["replica 3"]
+   end
+
+   subgraph Mayastor Volume
+      LV_1 --> VOL_1["1-replica volume"]
+      LV_2 --> VOL_2["2-replica volume"]
+      LV_3 --> VOL_2["2-replica volume"]
+   end
+
+   subgraph Physical Volumes
+      PV_1 --> VG_1["Volume Group - VG 1"]
+      PV_2 --> VG_1
+      PV_3 --> VG_2["Volume Group - VG 2"]
+   end
+
+   subgraph Node1
+      /dev/sda --> PV_1
+      /dev/sdb --> PV_2
+   end
+   subgraph Node2
+      /dev/sdc --> PV_3
+   end
+```

io-engine-tests/src/pool.rs

@@ -118,6 +118,7 @@ impl PoolBuilder {
                 uuid: None,
                 pooluuid: self.uuid.clone(),
                 query: None,
+                pooltypes: vec![],
             })
             .await
             .map(|r| r.into_inner().replicas)

io-engine-tests/src/replica.rs

@@ -228,6 +228,7 @@ pub async fn list_replicas(
             uuid: None,
             pooluuid: None,
             query: None,
+            pooltypes: vec![],
         })
         .await
         .map(|r| r.into_inner().replicas)
@@ -246,6 +247,7 @@ pub async fn find_replica_by_uuid(
             uuid: Some(uuid.to_owned()),
             pooluuid: None,
             query: None,
+            pooltypes: vec![],
         })
         .await
         .map(|r| r.into_inner().replicas)?

io-engine/src/bdev/lvs.rs

@@ -31,7 +31,7 @@ use crate::{
     bdev_api::BdevError,
     core::LogicalVolume,
     lvs::LvsLvol,
-    pool_backend::PoolArgs,
+    pool_backend::{PoolArgs, PoolBackend},
 };
 
 /// An lvol specified via URI.
@@ -215,6 +215,7 @@ impl Lvs {
             disks: vec![self.disk.to_owned()],
             uuid: None,
             cluster_size: None,
+            backend: PoolBackend::Lvs,
         };
         match &self.mode {
             LvsMode::Create => {

io-engine/src/bin/io-engine-client/main.rs

@@ -1,5 +1,6 @@
 use byte_unit::Byte;
 use snafu::{Backtrace, Snafu};
+use strum::ParseError;
 use tonic::transport::Channel;
 
 use io_engine_api::v0::{
@@ -23,6 +24,11 @@ pub enum ClientError {
         source: tonic::Status,
         backtrace: Backtrace,
     },
+    #[snafu(display("gRPC status: {}", source))]
+    GrpcParseStatus {
+        source: ParseError,
+        backtrace: Backtrace,
+    },
     #[snafu(display("Context building error: {}", source))]
     ContextCreate {
         source: context::Error,