[pve-devel] [PATCH manager 5/5] ceph pools: allow to create erasure code pools

[Aaron Lauterer <a.lauterer@proxmox.com>]

To use erasure coded (EC) pools for RBD storages, we need two pools. One
regular replicated pool that will hold the RBD omap and other metadata
and the EC pool which will hold the image data.

The coupling happens when an RBD image is created by adding the
--data-pool parameter. This is why we have the 'data-pool' parameter in
the storage configuration.

To follow already established semantics, we will create a 'X-metadata'
and 'X-data' pool. The storage configuration is always added as it is
the only thing that links the two together (besides naming schemes).

Different pg_num defaults are chosen for the replicated metadata pool as
it will not hold a lot of data.

Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>
---
we need some more follow ups as setting pool parameters on ec pools will
currently fail when trying to set the size. In that case, we most likely
should adapt the gui as well and make inon changeable settings, such as
size, read only.

changes since rfc:

ec profile parameters need to be configured during pool creation now. or
alternatively the name of an ec profile can be provided.

cleanup of ec profile & crush rule on pool destruction

 PVE/API2/Ceph/Pools.pm | 120 ++++++++++++++++++++++++++++++++++++++---
 PVE/Ceph/Tools.pm      |  11 ++--
 2 files changed, 122 insertions(+), 9 deletions(-)

diff --git a/PVE/API2/Ceph/Pools.pm b/PVE/API2/Ceph/Pools.pm
index 05855e15..69cf0d1a 100644
--- a/PVE/API2/Ceph/Pools.pm
+++ b/PVE/API2/Ceph/Pools.pm
@@ -280,7 +280,7 @@ my $ceph_pool_common_options = sub {
 
 
 my $add_storage = sub {
-    my ($pool, $storeid) = @_;
+    my ($pool, $storeid, $data_pool) = @_;
 
     my $storage_params = {
 	type => 'rbd',
@@ -290,6 +290,8 @@ my $add_storage = sub {
 	content => 'rootdir,images',
     };
 
+    $storage_params->{'data-pool'} = $data_pool if $data_pool;
+
     PVE::API2::Storage::Config->create($storage_params);
 };
 
@@ -330,10 +332,41 @@ __PACKAGE__->register_method ({
 	properties => {
 	    node => get_standard_option('pve-node'),
 	    add_storages => {
-		description => "Configure VM and CT storage using the new pool.",
+		description => "Configure VM and CT storage using the new pool. ".
+				"Always enabled for erasure coded pools.",
 		type => 'boolean',
 		optional => 1,
 	    },
+	    k => {
+		type => 'integer',
+		description => "Number of data chunks. Will create an erasure coded pool plus a ".
+				"replicated pool for metadata.",
+		optional => 1,
+	    },
+	    m => {
+		type => 'integer',
+		description => "Number of coding chunks. Will create an erasure coded pool plus a ".
+				"replicated pool for metadata.",
+		optional => 1,
+	    },
+	    'failure-domain' => {
+		type => 'string',
+		description => "CRUSH failure domain. Default is 'host'. Will create an erasure ".
+				"coded pool plus a replicated pool for metadata.",
+		optional => 1,
+	    },
+	    'device-class' => {
+		type => 'string',
+		description => "CRUSH device class. Will create an erasure coded pool plus a ".
+				"replicated pool for metadata.",
+		optional => 1,
+	    },
+	    ecprofile => {
+		description => "Override the erasure code (EC) profile to use. Will create an ".
+				"erasure coded pool plus a replicated pool for metadata.",
+		type => 'string',
+		optional => 1,
+	    },
 	    %{ $ceph_pool_common_options->() },
 	},
     },
@@ -344,10 +377,31 @@ __PACKAGE__->register_method ({
 	PVE::Cluster::check_cfs_quorum();
 	PVE::Ceph::Tools::check_ceph_configured();
 
-	my $pool = extract_param($param, 'name');
+	my $pool = my $name = extract_param($param, 'name');
 	my $node = extract_param($param, 'node');
 	my $add_storages = extract_param($param, 'add_storages');
 
+	my $ec_k = extract_param($param, 'k');
+	my $ec_m = extract_param($param, 'm');
+	my $ec_failure_domain = extract_param($param, 'failure-domain');
+	my $ec_device_class = extract_param($param, 'device-class');
+
+	my $is_ec = 0;
+
+	my $ecprofile = extract_param($param, 'ecprofile');
+	die "Erasure code profile '$ecprofile' does not exist.\n"
+	    if $ecprofile && !PVE::Ceph::Tools::ecprofile_exists($ecprofile);
+
+	if ($ec_k || $ec_m || $ec_failure_domain || $ec_device_class) {
+	    die "'k' and 'm' parameters are needed for an erasure coded pool\n"
+		if !$ec_k || !$ec_m;
+
+	    $is_ec = 1;
+	}
+
+	$is_ec = 1 if $ecprofile;
+	$add_storages = 1 if $is_ec;
+
 	my $rpcenv = PVE::RPCEnvironment::get();
 	my $user = $rpcenv->get_user();
 
@@ -370,13 +424,47 @@ __PACKAGE__->register_method ({
 	$param->{application} //= 'rbd';
 	$param->{pg_autoscale_mode} //= 'warn';
 
-	my $worker = sub {
+	my $data_param = {};
+	my $data_pool = '';
+	if (!$ecprofile) {
+	    $ecprofile = PVE::Ceph::Tools::get_ecprofile_name($pool);
+	    eval {
+		PVE::Ceph::Tools::create_ecprofile(
+		    $ecprofile,
+		    $ec_k,
+		    $ec_m,
+		    $ec_failure_domain,
+		    $ec_device_class,
+		);
+	    };
+	    die "could not create erasure code profile '$ecprofile': $@\n" if $@;
+	}
+
+	if ($is_ec) {
+	    # copy all params, should be a flat hash
+	    $data_param = { map { $_ => $param->{$_} } keys %$param };
 
+	    $data_param->{pool_type} = 'erasure';
+	    $data_param->{allow_ec_overwrites} = 'true';
+	    $data_param->{erasure_code_profile} = $ecprofile;
+	    delete $data_param->{size};
+	    delete $data_param->{min_size};
+
+	    # metadata pool should be ok with 32 PGs
+	    $param->{pg_num} = 32;
+
+	    $pool = "${name}-metadata";
+	    $data_pool = "${name}-data";
+	}
+
+	my $worker = sub {
 	    PVE::Ceph::Tools::create_pool($pool, $param);
 
+	    PVE::Ceph::Tools::create_pool($data_pool, $data_param) if $is_ec;
+
 	    if ($add_storages) {
-		eval { $add_storage->($pool, "${pool}") };
-		die "adding PVE storage for ceph pool '$pool' failed: $@\n" if $@;
+		eval { $add_storage->($pool, "${name}", $data_pool) };
+		die "adding PVE storage for ceph pool '$name' failed: $@\n" if $@;
 	    }
 	};
 
@@ -414,6 +502,12 @@ __PACKAGE__->register_method ({
 		optional => 1,
 		default => 0,
 	    },
+	    remove_ecprofile => {
+		description => "Remove the erasure code profile. Used for erasure code pools. Default is true",
+		type => 'boolean',
+		optional => 1,
+		default => 1,
+	    },
 	},
     },
     returns => { type => 'string' },
@@ -428,6 +522,7 @@ __PACKAGE__->register_method ({
 	    if $param->{remove_storages};
 
 	my $pool = $param->{name};
+	my $remove_ecprofile = $param->{remove_ecprofile} // 1;
 
 	my $worker = sub {
 	    my $storages = $get_storages->($pool);
@@ -447,8 +542,21 @@ __PACKAGE__->register_method ({
 		}
 	    }
 
+	    my $pool_properties = PVE::Ceph::Tools::get_pool_properties($pool);
+
 	    PVE::Ceph::Tools::destroy_pool($pool);
 
+	    if (my $ecprofile = $pool_properties->{erasure_code_profile}) {
+		my $crush_rule = $pool_properties->{crush_rule};
+		eval { PVE::Ceph::Tools::destroy_crush_rule($crush_rule); };
+		warn "removing crush rule '${crush_rule}' failed: $@\n" if $@;
+
+		if ($remove_ecprofile) {
+		    eval { PVE::Ceph::Tools::destroy_ecprofile($ecprofile) };
+		    warn "removing EC profile '${ecprofile}' failed: $@\n" if $@;
+		}
+	    }
+
 	    if ($param->{remove_storages}) {
 		my $err;
 		foreach my $storeid (keys %$storages) {
diff --git a/PVE/Ceph/Tools.pm b/PVE/Ceph/Tools.pm
index 7e94ee58..f50cec67 100644
--- a/PVE/Ceph/Tools.pm
+++ b/PVE/Ceph/Tools.pm
@@ -8,7 +8,7 @@ use File::Basename;
 use IO::File;
 use JSON;
 
-use PVE::Tools qw(run_command dir_glob_foreach);
+use PVE::Tools qw(run_command dir_glob_foreach extract_param);
 use PVE::Cluster qw(cfs_read_file);
 use PVE::RADOS;
 use PVE::Ceph::Services;
@@ -277,12 +277,17 @@ sub create_pool {
 
     my $pg_num = $param->{pg_num} || 128;
 
-    $rados->mon_command({
+    my $mon_params = {
 	prefix => "osd pool create",
 	pool => $pool,
 	pg_num => int($pg_num),
 	format => 'plain',
-    });
+    };
+    $mon_params->{pool_type} = extract_param($param, 'pool_type') if $param->{pool_type};
+    $mon_params->{erasure_code_profile} = extract_param($param, 'erasure_code_profile')
+	if $param->{erasure_code_profile};
+
+    $rados->mon_command($mon_params);
 
     set_pool($pool, $param);
 
-- 
2.30.2