[RFC pve-storage 02/27] diskmanage: add helper to list multipath devices

[Dietmar Maurer <dietmar@proxmox.com>]

Multipath mapped devices are deliberately not part of get_disks, whose
callers (node disk list, local storage creation, ceph OSDs) manage
local disks only. The storage wizard however needs to offer SAN LUNs,
which on production FC/SAS setups are usually multipath devices.

Aggregate vendor, model and transport from the member paths and reuse
the usage detection of get_disks, so callers can tell whether a LUN is
unused, already an LVM physical volume or otherwise occupied.

Signed-off-by: Dietmar Maurer <dietmar@proxmox.com>
---
 src/PVE/Diskmanage.pm                         | 79 ++++++++++++++++++-
 src/test/disk_tests/multipath/disklist        |  9 +++
 .../multipath/disklist_expected.json          | 74 +++++++++++++++++
 src/test/disk_tests/multipath/dm-0/dm/name    |  1 +
 src/test/disk_tests/multipath/dm-0/dm/uuid    |  1 +
 src/test/disk_tests/multipath/dm-0/size       |  1 +
 src/test/disk_tests/multipath/dm-0_slaves     |  4 +
 src/test/disk_tests/multipath/dm-1/dm/name    |  1 +
 src/test/disk_tests/multipath/dm-1/dm/uuid    |  1 +
 src/test/disk_tests/multipath/dm-1/size       |  1 +
 src/test/disk_tests/multipath/dm-1_slaves     |  4 +
 src/test/disk_tests/multipath/dm-2/dm/name    |  1 +
 src/test/disk_tests/multipath/dm-2/dm/uuid    |  1 +
 src/test/disk_tests/multipath/dm-2/size       |  1 +
 src/test/disk_tests/multipath/dm-2_slaves     |  1 +
 src/test/disk_tests/multipath/dm-3/dm/name    |  1 +
 src/test/disk_tests/multipath/dm-3/dm/uuid    |  1 +
 src/test/disk_tests/multipath/dm-3/size       |  1 +
 src/test/disk_tests/multipath/dm-3_slaves     |  1 +
 src/test/disk_tests/multipath/dm-4/dm/name    |  1 +
 src/test/disk_tests/multipath/dm-4/dm/uuid    |  1 +
 src/test/disk_tests/multipath/dm-4/size       |  1 +
 src/test/disk_tests/multipath/dm-4_slaves     |  1 +
 src/test/disk_tests/multipath/lsblk           | 63 +++++++++++++++
 src/test/disk_tests/multipath/lvs             |  0
 src/test/disk_tests/multipath/mounts          |  1 +
 .../multipath/multipath_expected.json         | 59 ++++++++++++++
 src/test/disk_tests/multipath/partlist        |  0
 src/test/disk_tests/multipath/pvs             |  1 +
 .../disk_tests/multipath/sda/device/model     |  1 +
 .../disk_tests/multipath/sda/device/vendor    |  1 +
 .../disk_tests/multipath/sda/holders/holder   |  1 +
 .../disk_tests/multipath/sda/queue/rotational |  1 +
 src/test/disk_tests/multipath/sda/size        |  1 +
 src/test/disk_tests/multipath/sda_udevadm     | 18 +++++
 .../disk_tests/multipath/sdb/device/model     |  1 +
 .../disk_tests/multipath/sdb/device/vendor    |  1 +
 .../disk_tests/multipath/sdb/holders/holder   |  1 +
 .../disk_tests/multipath/sdb/queue/rotational |  1 +
 src/test/disk_tests/multipath/sdb/size        |  1 +
 src/test/disk_tests/multipath/sdb_udevadm     | 18 +++++
 .../disk_tests/multipath/sdc/device/model     |  1 +
 .../disk_tests/multipath/sdc/device/vendor    |  1 +
 .../disk_tests/multipath/sdc/holders/holder   |  1 +
 .../disk_tests/multipath/sdc/queue/rotational |  1 +
 src/test/disk_tests/multipath/sdc/size        |  1 +
 src/test/disk_tests/multipath/sdc_udevadm     | 18 +++++
 .../disk_tests/multipath/sdd/device/model     |  1 +
 .../disk_tests/multipath/sdd/device/vendor    |  1 +
 .../disk_tests/multipath/sdd/holders/holder   |  1 +
 .../disk_tests/multipath/sdd/queue/rotational |  1 +
 src/test/disk_tests/multipath/sdd/size        |  1 +
 src/test/disk_tests/multipath/sdd_udevadm     | 18 +++++
 src/test/disk_tests/multipath/zpool           |  1 +
 src/test/disklist_test.pm                     | 49 +++++++++++-
 55 files changed, 452 insertions(+), 2 deletions(-)
 create mode 100644 src/test/disk_tests/multipath/disklist
 create mode 100644 src/test/disk_tests/multipath/disklist_expected.json
 create mode 100644 src/test/disk_tests/multipath/dm-0/dm/name
 create mode 100644 src/test/disk_tests/multipath/dm-0/dm/uuid
 create mode 100644 src/test/disk_tests/multipath/dm-0/size
 create mode 100644 src/test/disk_tests/multipath/dm-0_slaves
 create mode 100644 src/test/disk_tests/multipath/dm-1/dm/name
 create mode 100644 src/test/disk_tests/multipath/dm-1/dm/uuid
 create mode 100644 src/test/disk_tests/multipath/dm-1/size
 create mode 100644 src/test/disk_tests/multipath/dm-1_slaves
 create mode 100644 src/test/disk_tests/multipath/dm-2/dm/name
 create mode 100644 src/test/disk_tests/multipath/dm-2/dm/uuid
 create mode 100644 src/test/disk_tests/multipath/dm-2/size
 create mode 100644 src/test/disk_tests/multipath/dm-2_slaves
 create mode 100644 src/test/disk_tests/multipath/dm-3/dm/name
 create mode 100644 src/test/disk_tests/multipath/dm-3/dm/uuid
 create mode 100644 src/test/disk_tests/multipath/dm-3/size
 create mode 100644 src/test/disk_tests/multipath/dm-3_slaves
 create mode 100644 src/test/disk_tests/multipath/dm-4/dm/name
 create mode 100644 src/test/disk_tests/multipath/dm-4/dm/uuid
 create mode 100644 src/test/disk_tests/multipath/dm-4/size
 create mode 100644 src/test/disk_tests/multipath/dm-4_slaves
 create mode 100644 src/test/disk_tests/multipath/lsblk
 create mode 100644 src/test/disk_tests/multipath/lvs
 create mode 100644 src/test/disk_tests/multipath/mounts
 create mode 100644 src/test/disk_tests/multipath/multipath_expected.json
 create mode 100644 src/test/disk_tests/multipath/partlist
 create mode 100644 src/test/disk_tests/multipath/pvs
 create mode 100644 src/test/disk_tests/multipath/sda/device/model
 create mode 100644 src/test/disk_tests/multipath/sda/device/vendor
 create mode 100644 src/test/disk_tests/multipath/sda/holders/holder
 create mode 100644 src/test/disk_tests/multipath/sda/queue/rotational
 create mode 100644 src/test/disk_tests/multipath/sda/size
 create mode 100644 src/test/disk_tests/multipath/sda_udevadm
 create mode 100644 src/test/disk_tests/multipath/sdb/device/model
 create mode 100644 src/test/disk_tests/multipath/sdb/device/vendor
 create mode 100644 src/test/disk_tests/multipath/sdb/holders/holder
 create mode 100644 src/test/disk_tests/multipath/sdb/queue/rotational
 create mode 100644 src/test/disk_tests/multipath/sdb/size
 create mode 100644 src/test/disk_tests/multipath/sdb_udevadm
 create mode 100644 src/test/disk_tests/multipath/sdc/device/model
 create mode 100644 src/test/disk_tests/multipath/sdc/device/vendor
 create mode 100644 src/test/disk_tests/multipath/sdc/holders/holder
 create mode 100644 src/test/disk_tests/multipath/sdc/queue/rotational
 create mode 100644 src/test/disk_tests/multipath/sdc/size
 create mode 100644 src/test/disk_tests/multipath/sdc_udevadm
 create mode 100644 src/test/disk_tests/multipath/sdd/device/model
 create mode 100644 src/test/disk_tests/multipath/sdd/device/vendor
 create mode 100644 src/test/disk_tests/multipath/sdd/holders/holder
 create mode 100644 src/test/disk_tests/multipath/sdd/queue/rotational
 create mode 100644 src/test/disk_tests/multipath/sdd/size
 create mode 100644 src/test/disk_tests/multipath/sdd_udevadm
 create mode 100644 src/test/disk_tests/multipath/zpool

diff --git a/src/PVE/Diskmanage.pm b/src/PVE/Diskmanage.pm
index c04408e..ed5181f 100644
--- a/src/PVE/Diskmanage.pm
+++ b/src/PVE/Diskmanage.pm
@@ -174,7 +174,7 @@ sub get_smart_data {
 }
 
 sub get_lsblk_info {
-    my $cmd = [$LSBLK, '--json', '-o', 'path,parttype,fstype,tran'];
+    my $cmd = [$LSBLK, '--json', '-o', 'path,parttype,fstype,tran,pttype'];
     my $output = "";
     eval {
         run_command($cmd, outfunc => sub { $output .= "$_[0]\n"; });
@@ -192,6 +192,7 @@ sub get_lsblk_info {
                 parttype => $_->{parttype},
                 fstype => $_->{fstype},
                 tran => $_->{tran},
+                pttype => $_->{pttype},
             }
         } @{$list}
     };
@@ -771,6 +772,82 @@ sub get_disks {
     return $disklist;
 }
 
+# Lists multipath mapped devices with information aggregated from their member paths, keyed by
+# their kernel device name (dm-X). These are deliberately not returned by get_disks, as its
+# callers manage local disks only.
+sub get_multipath_disks {
+    my $mounted = mounted_blockdevs();
+    my $lsblk_info = get_lsblk_info();
+    my $zfshash = get_zfs_devices($lsblk_info);
+    my $lvmhash = get_lvm_devices($lsblk_info);
+
+    my $disklist = {};
+
+    dir_glob_foreach(
+        '/sys/block',
+        'dm-\d+',
+        sub {
+            my ($dev) = @_;
+            my $sysdir = "/sys/block/$dev";
+
+            my $uuid = file_read_firstline("$sysdir/dm/uuid") // return;
+            return if $uuid !~ m/^mpath-(\S+)$/;
+            my $wwid = $1;
+
+            my $name = file_read_firstline("$sysdir/dm/name") // return;
+            my $devpath = "/dev/mapper/$name";
+            my $resolved_devpath = abs_path($devpath);
+            my @devpaths = ($devpath);
+            push @devpaths, $resolved_devpath
+                if defined($resolved_devpath) && $resolved_devpath ne $devpath;
+
+            my $size = get_sysdir_size($sysdir) or return;
+
+            my $slaves = [];
+            dir_glob_foreach("$sysdir/slaves", '[^.].*', sub { push @$slaves, $_[0]; });
+            @$slaves = sort @$slaves;
+
+            my ($vendor, $model, $transport) = ('unknown', 'unknown', undef);
+            if (my $first = $slaves->[0]) {
+                if (my $sysdata = get_sysdir_info("/sys/block/$first")) {
+                    $vendor = $sysdata->{vendor};
+                    $model = $sysdata->{model};
+                }
+                $transport = $lsblk_info->{"/dev/$first"}->{tran};
+            }
+
+            my $used;
+            $used = 'LVM' if grep { $lvmhash->{$_} } @devpaths;
+            $used //= 'ZFS' if grep { $zfshash->{$_} } @devpaths;
+            my $info = {};
+            for my $path (@devpaths) {
+                $info = $lsblk_info->{$path} // next;
+                last;
+            }
+            $used //= "$info->{fstype}" if defined($info->{fstype});
+            $used //= 'mounted' if grep { $mounted->{$_} } @devpaths;
+            $used //= 'partitions'
+                if defined($info->{pttype}) && $info->{pttype} ne '';
+            # partition mappings and other stacked devices show up as holders
+            $used //= 'Device Mapper' if !dir_is_empty("$sysdir/holders");
+
+            $disklist->{$dev} = {
+                devpath => $devpath,
+                size => $size,
+                vendor => $vendor,
+                model => $model,
+                wwn => $wwid,
+                paths => scalar($slaves->@*),
+                slaves => [map { "/dev/$_" } $slaves->@*],
+            };
+            $disklist->{$dev}->{transport} = $transport if defined($transport);
+            $disklist->{$dev}->{used} = $used if $used;
+        },
+    );
+
+    return $disklist;
+}
+
 sub get_partnum {
     my ($part_path) = @_;
 
diff --git a/src/test/disk_tests/multipath/disklist b/src/test/disk_tests/multipath/disklist
new file mode 100644
index 0000000..9293589
--- /dev/null
+++ b/src/test/disk_tests/multipath/disklist
@@ -0,0 +1,9 @@
+sda
+sdb
+sdc
+sdd
+dm-0
+dm-1
+dm-2
+dm-3
+dm-4
diff --git a/src/test/disk_tests/multipath/disklist_expected.json b/src/test/disk_tests/multipath/disklist_expected.json
new file mode 100644
index 0000000..a8e74fa
--- /dev/null
+++ b/src/test/disk_tests/multipath/disklist_expected.json
@@ -0,0 +1,74 @@
+{
+    "sda": {
+        "devpath": "/dev/sda",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "serial": "SSERa",
+        "wwn": "0x600140500000000a",
+        "gpt": 0,
+        "rpm": -1,
+        "type": "unknown",
+        "health": "UNKNOWN",
+        "wearout": "N/A",
+        "osdid": -1,
+        "osdid-list": null,
+        "by_id_link": "/dev/disk/by-id/scsi-36001405000000000000000000000000a",
+        "transport": "fc",
+        "used": "Device Mapper"
+    },
+    "sdb": {
+        "devpath": "/dev/sdb",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "serial": "SSERb",
+        "wwn": "0x600140500000000b",
+        "gpt": 0,
+        "rpm": -1,
+        "type": "unknown",
+        "health": "UNKNOWN",
+        "wearout": "N/A",
+        "osdid": -1,
+        "osdid-list": null,
+        "by_id_link": "/dev/disk/by-id/scsi-36001405000000000000000000000000b",
+        "transport": "fc",
+        "used": "Device Mapper"
+    },
+    "sdc": {
+        "devpath": "/dev/sdc",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "serial": "SSERc",
+        "wwn": "0x600140500000000c",
+        "gpt": 0,
+        "rpm": -1,
+        "type": "unknown",
+        "health": "UNKNOWN",
+        "wearout": "N/A",
+        "osdid": -1,
+        "osdid-list": null,
+        "by_id_link": "/dev/disk/by-id/scsi-36001405000000000000000000000000c",
+        "transport": "fc",
+        "used": "Device Mapper"
+    },
+    "sdd": {
+        "devpath": "/dev/sdd",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "serial": "SSERd",
+        "wwn": "0x600140500000000d",
+        "gpt": 0,
+        "rpm": -1,
+        "type": "unknown",
+        "health": "UNKNOWN",
+        "wearout": "N/A",
+        "osdid": -1,
+        "osdid-list": null,
+        "by_id_link": "/dev/disk/by-id/scsi-36001405000000000000000000000000d",
+        "transport": "fc",
+        "used": "Device Mapper"
+    }
+}
diff --git a/src/test/disk_tests/multipath/dm-0/dm/name b/src/test/disk_tests/multipath/dm-0/dm/name
new file mode 100644
index 0000000..0ed057a
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-0/dm/name
@@ -0,0 +1 @@
+mpatha
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-0/dm/uuid b/src/test/disk_tests/multipath/dm-0/dm/uuid
new file mode 100644
index 0000000..094955a
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-0/dm/uuid
@@ -0,0 +1 @@
+mpath-3600140500000000000000000000000001
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-0/size b/src/test/disk_tests/multipath/dm-0/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-0/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-0_slaves b/src/test/disk_tests/multipath/dm-0_slaves
new file mode 100644
index 0000000..1637315
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-0_slaves
@@ -0,0 +1,4 @@
+.
+..
+sda
+sdb
diff --git a/src/test/disk_tests/multipath/dm-1/dm/name b/src/test/disk_tests/multipath/dm-1/dm/name
new file mode 100644
index 0000000..f70ac3d
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-1/dm/name
@@ -0,0 +1 @@
+mpathb
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-1/dm/uuid b/src/test/disk_tests/multipath/dm-1/dm/uuid
new file mode 100644
index 0000000..7e8567b
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-1/dm/uuid
@@ -0,0 +1 @@
+mpath-3600140500000000000000000000000002
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-1/size b/src/test/disk_tests/multipath/dm-1/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-1/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/dm-1_slaves b/src/test/disk_tests/multipath/dm-1_slaves
new file mode 100644
index 0000000..cde08b3
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-1_slaves
@@ -0,0 +1,4 @@
+.
+..
+sdc
+sdd
diff --git a/src/test/disk_tests/multipath/dm-2/dm/name b/src/test/disk_tests/multipath/dm-2/dm/name
new file mode 100644
index 0000000..4770de4
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-2/dm/name
@@ -0,0 +1 @@
+mpathc
diff --git a/src/test/disk_tests/multipath/dm-2/dm/uuid b/src/test/disk_tests/multipath/dm-2/dm/uuid
new file mode 100644
index 0000000..2d607ea
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-2/dm/uuid
@@ -0,0 +1 @@
+mpath-3600140500000000000000000000000003
diff --git a/src/test/disk_tests/multipath/dm-2/size b/src/test/disk_tests/multipath/dm-2/size
new file mode 100644
index 0000000..14faeec
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-2/size
@@ -0,0 +1 @@
+20971520
diff --git a/src/test/disk_tests/multipath/dm-2_slaves b/src/test/disk_tests/multipath/dm-2_slaves
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-2_slaves
@@ -0,0 +1 @@
+
diff --git a/src/test/disk_tests/multipath/dm-3/dm/name b/src/test/disk_tests/multipath/dm-3/dm/name
new file mode 100644
index 0000000..a98ef69
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-3/dm/name
@@ -0,0 +1 @@
+mpathd
diff --git a/src/test/disk_tests/multipath/dm-3/dm/uuid b/src/test/disk_tests/multipath/dm-3/dm/uuid
new file mode 100644
index 0000000..75f25b8
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-3/dm/uuid
@@ -0,0 +1 @@
+mpath-3600140500000000000000000000000004
diff --git a/src/test/disk_tests/multipath/dm-3/size b/src/test/disk_tests/multipath/dm-3/size
new file mode 100644
index 0000000..14faeec
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-3/size
@@ -0,0 +1 @@
+20971520
diff --git a/src/test/disk_tests/multipath/dm-3_slaves b/src/test/disk_tests/multipath/dm-3_slaves
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-3_slaves
@@ -0,0 +1 @@
+
diff --git a/src/test/disk_tests/multipath/dm-4/dm/name b/src/test/disk_tests/multipath/dm-4/dm/name
new file mode 100644
index 0000000..e084e8f
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-4/dm/name
@@ -0,0 +1 @@
+mpathe
diff --git a/src/test/disk_tests/multipath/dm-4/dm/uuid b/src/test/disk_tests/multipath/dm-4/dm/uuid
new file mode 100644
index 0000000..0ca7875
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-4/dm/uuid
@@ -0,0 +1 @@
+mpath-3600140500000000000000000000000005
diff --git a/src/test/disk_tests/multipath/dm-4/size b/src/test/disk_tests/multipath/dm-4/size
new file mode 100644
index 0000000..14faeec
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-4/size
@@ -0,0 +1 @@
+20971520
diff --git a/src/test/disk_tests/multipath/dm-4_slaves b/src/test/disk_tests/multipath/dm-4_slaves
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/test/disk_tests/multipath/dm-4_slaves
@@ -0,0 +1 @@
+
diff --git a/src/test/disk_tests/multipath/lsblk b/src/test/disk_tests/multipath/lsblk
new file mode 100644
index 0000000..91f7457
--- /dev/null
+++ b/src/test/disk_tests/multipath/lsblk
@@ -0,0 +1,63 @@
+{
+   "blockdevices": [
+      {
+         "path": "/dev/sda",
+         "parttype": null,
+         "fstype": null,
+         "tran": "fc"
+      },
+      {
+         "path": "/dev/sdb",
+         "parttype": null,
+         "fstype": null,
+         "tran": "fc"
+      },
+      {
+         "path": "/dev/sdc",
+         "parttype": null,
+         "fstype": null,
+         "tran": "fc"
+      },
+      {
+         "path": "/dev/sdd",
+         "parttype": null,
+         "fstype": null,
+         "tran": "fc"
+      },
+      {
+         "path": "/dev/mapper/mpatha",
+         "parttype": null,
+         "fstype": null,
+         "tran": null,
+         "pttype": null
+      },
+      {
+         "path": "/dev/mapper/mpathb",
+         "parttype": null,
+         "fstype": null,
+         "tran": null,
+         "pttype": null
+      },
+      {
+         "path": "/dev/mapper/mpathc",
+         "parttype": null,
+         "fstype": null,
+         "tran": null,
+         "pttype": "gpt"
+      },
+      {
+         "path": "/dev/dm-3",
+         "parttype": null,
+         "fstype": null,
+         "tran": null,
+         "pttype": null
+      },
+      {
+         "path": "/dev/dm-4",
+         "parttype": null,
+         "fstype": null,
+         "tran": null,
+         "pttype": null
+      }
+   ]
+}
diff --git a/src/test/disk_tests/multipath/lvs b/src/test/disk_tests/multipath/lvs
new file mode 100644
index 0000000..e69de29
diff --git a/src/test/disk_tests/multipath/mounts b/src/test/disk_tests/multipath/mounts
new file mode 100644
index 0000000..06ada27
--- /dev/null
+++ b/src/test/disk_tests/multipath/mounts
@@ -0,0 +1 @@
+/dev/mapper/mpathe /mnt
diff --git a/src/test/disk_tests/multipath/multipath_expected.json b/src/test/disk_tests/multipath/multipath_expected.json
new file mode 100644
index 0000000..62e6e1c
--- /dev/null
+++ b/src/test/disk_tests/multipath/multipath_expected.json
@@ -0,0 +1,59 @@
+{
+    "dm-0": {
+        "devpath": "/dev/mapper/mpatha",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "wwn": "3600140500000000000000000000000001",
+        "paths": 2,
+        "slaves": [
+            "/dev/sda",
+            "/dev/sdb"
+        ],
+        "transport": "fc"
+    },
+    "dm-1": {
+        "devpath": "/dev/mapper/mpathb",
+        "size": 10737418240,
+        "vendor": "SANVEND",
+        "model": "SANMODEL",
+        "wwn": "3600140500000000000000000000000002",
+        "paths": 2,
+        "slaves": [
+            "/dev/sdc",
+            "/dev/sdd"
+        ],
+        "transport": "fc",
+        "used": "LVM"
+    },
+    "dm-2": {
+        "devpath": "/dev/mapper/mpathc",
+        "size": 10737418240,
+        "vendor": "unknown",
+        "model": "unknown",
+        "wwn": "3600140500000000000000000000000003",
+        "paths": 0,
+        "slaves": [],
+        "used": "partitions"
+    },
+    "dm-3": {
+        "devpath": "/dev/mapper/mpathd",
+        "size": 10737418240,
+        "vendor": "unknown",
+        "model": "unknown",
+        "wwn": "3600140500000000000000000000000004",
+        "paths": 0,
+        "slaves": [],
+        "used": "ZFS"
+    },
+    "dm-4": {
+        "devpath": "/dev/mapper/mpathe",
+        "size": 10737418240,
+        "vendor": "unknown",
+        "model": "unknown",
+        "wwn": "3600140500000000000000000000000005",
+        "paths": 0,
+        "slaves": [],
+        "used": "mounted"
+    }
+}
diff --git a/src/test/disk_tests/multipath/partlist b/src/test/disk_tests/multipath/partlist
new file mode 100644
index 0000000..e69de29
diff --git a/src/test/disk_tests/multipath/pvs b/src/test/disk_tests/multipath/pvs
new file mode 100644
index 0000000..9c2f9b9
--- /dev/null
+++ b/src/test/disk_tests/multipath/pvs
@@ -0,0 +1 @@
+  /dev/dm-1
diff --git a/src/test/disk_tests/multipath/sda/device/model b/src/test/disk_tests/multipath/sda/device/model
new file mode 100644
index 0000000..2f50f3f
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda/device/model
@@ -0,0 +1 @@
+SANMODEL
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sda/device/vendor b/src/test/disk_tests/multipath/sda/device/vendor
new file mode 100644
index 0000000..ead8944
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda/device/vendor
@@ -0,0 +1 @@
+SANVEND
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sda/holders/holder b/src/test/disk_tests/multipath/sda/holders/holder
new file mode 100644
index 0000000..9255a92
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda/holders/holder
@@ -0,0 +1 @@
+dm-holder
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sda/queue/rotational b/src/test/disk_tests/multipath/sda/queue/rotational
new file mode 100644
index 0000000..56a6051
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda/queue/rotational
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sda/size b/src/test/disk_tests/multipath/sda/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sda_udevadm b/src/test/disk_tests/multipath/sda_udevadm
new file mode 100644
index 0000000..7bd58b4
--- /dev/null
+++ b/src/test/disk_tests/multipath/sda_udevadm
@@ -0,0 +1,18 @@
+P: /devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sda
+N: sda
+S: disk/by-id/scsi-36001405000000000000000000000000a
+E: DEVLINKS=/dev/disk/by-id/scsi-36001405000000000000000000000000a
+E: DEVNAME=/dev/sda
+E: DEVPATH=/devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sda
+E: DEVTYPE=disk
+E: ID_BUS=scsi
+E: ID_MODEL=SANMODEL
+E: ID_SCSI=1
+E: ID_SERIAL=SANSERIALa
+E: ID_SERIAL_SHORT=SSERa
+E: ID_TYPE=disk
+E: ID_VENDOR=SANVEND
+E: ID_WWN=0x600140500000000a
+E: MAJOR=8
+E: MINOR=0
+E: SUBSYSTEM=block
diff --git a/src/test/disk_tests/multipath/sdb/device/model b/src/test/disk_tests/multipath/sdb/device/model
new file mode 100644
index 0000000..2f50f3f
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb/device/model
@@ -0,0 +1 @@
+SANMODEL
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdb/device/vendor b/src/test/disk_tests/multipath/sdb/device/vendor
new file mode 100644
index 0000000..ead8944
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb/device/vendor
@@ -0,0 +1 @@
+SANVEND
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdb/holders/holder b/src/test/disk_tests/multipath/sdb/holders/holder
new file mode 100644
index 0000000..9255a92
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb/holders/holder
@@ -0,0 +1 @@
+dm-holder
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdb/queue/rotational b/src/test/disk_tests/multipath/sdb/queue/rotational
new file mode 100644
index 0000000..56a6051
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb/queue/rotational
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdb/size b/src/test/disk_tests/multipath/sdb/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdb_udevadm b/src/test/disk_tests/multipath/sdb_udevadm
new file mode 100644
index 0000000..9a04c63
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdb_udevadm
@@ -0,0 +1,18 @@
+P: /devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdb
+N: sdb
+S: disk/by-id/scsi-36001405000000000000000000000000b
+E: DEVLINKS=/dev/disk/by-id/scsi-36001405000000000000000000000000b
+E: DEVNAME=/dev/sdb
+E: DEVPATH=/devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdb
+E: DEVTYPE=disk
+E: ID_BUS=scsi
+E: ID_MODEL=SANMODEL
+E: ID_SCSI=1
+E: ID_SERIAL=SANSERIALb
+E: ID_SERIAL_SHORT=SSERb
+E: ID_TYPE=disk
+E: ID_VENDOR=SANVEND
+E: ID_WWN=0x600140500000000b
+E: MAJOR=8
+E: MINOR=0
+E: SUBSYSTEM=block
diff --git a/src/test/disk_tests/multipath/sdc/device/model b/src/test/disk_tests/multipath/sdc/device/model
new file mode 100644
index 0000000..2f50f3f
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc/device/model
@@ -0,0 +1 @@
+SANMODEL
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdc/device/vendor b/src/test/disk_tests/multipath/sdc/device/vendor
new file mode 100644
index 0000000..ead8944
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc/device/vendor
@@ -0,0 +1 @@
+SANVEND
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdc/holders/holder b/src/test/disk_tests/multipath/sdc/holders/holder
new file mode 100644
index 0000000..9255a92
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc/holders/holder
@@ -0,0 +1 @@
+dm-holder
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdc/queue/rotational b/src/test/disk_tests/multipath/sdc/queue/rotational
new file mode 100644
index 0000000..56a6051
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc/queue/rotational
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdc/size b/src/test/disk_tests/multipath/sdc/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdc_udevadm b/src/test/disk_tests/multipath/sdc_udevadm
new file mode 100644
index 0000000..acff253
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdc_udevadm
@@ -0,0 +1,18 @@
+P: /devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdc
+N: sdc
+S: disk/by-id/scsi-36001405000000000000000000000000c
+E: DEVLINKS=/dev/disk/by-id/scsi-36001405000000000000000000000000c
+E: DEVNAME=/dev/sdc
+E: DEVPATH=/devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdc
+E: DEVTYPE=disk
+E: ID_BUS=scsi
+E: ID_MODEL=SANMODEL
+E: ID_SCSI=1
+E: ID_SERIAL=SANSERIALc
+E: ID_SERIAL_SHORT=SSERc
+E: ID_TYPE=disk
+E: ID_VENDOR=SANVEND
+E: ID_WWN=0x600140500000000c
+E: MAJOR=8
+E: MINOR=0
+E: SUBSYSTEM=block
diff --git a/src/test/disk_tests/multipath/sdd/device/model b/src/test/disk_tests/multipath/sdd/device/model
new file mode 100644
index 0000000..2f50f3f
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd/device/model
@@ -0,0 +1 @@
+SANMODEL
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdd/device/vendor b/src/test/disk_tests/multipath/sdd/device/vendor
new file mode 100644
index 0000000..ead8944
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd/device/vendor
@@ -0,0 +1 @@
+SANVEND
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdd/holders/holder b/src/test/disk_tests/multipath/sdd/holders/holder
new file mode 100644
index 0000000..9255a92
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd/holders/holder
@@ -0,0 +1 @@
+dm-holder
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdd/queue/rotational b/src/test/disk_tests/multipath/sdd/queue/rotational
new file mode 100644
index 0000000..56a6051
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd/queue/rotational
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdd/size b/src/test/disk_tests/multipath/sdd/size
new file mode 100644
index 0000000..8280959
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd/size
@@ -0,0 +1 @@
+20971520
\ No newline at end of file
diff --git a/src/test/disk_tests/multipath/sdd_udevadm b/src/test/disk_tests/multipath/sdd_udevadm
new file mode 100644
index 0000000..813c5f1
--- /dev/null
+++ b/src/test/disk_tests/multipath/sdd_udevadm
@@ -0,0 +1,18 @@
+P: /devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdd
+N: sdd
+S: disk/by-id/scsi-36001405000000000000000000000000d
+E: DEVLINKS=/dev/disk/by-id/scsi-36001405000000000000000000000000d
+E: DEVNAME=/dev/sdd
+E: DEVPATH=/devices/pci0000:00/0000:00:03.0/0000:02:00.0/host4/rport-4:0-0/target4:0:0/4:0:0:0/block/sdd
+E: DEVTYPE=disk
+E: ID_BUS=scsi
+E: ID_MODEL=SANMODEL
+E: ID_SCSI=1
+E: ID_SERIAL=SANSERIALd
+E: ID_SERIAL_SHORT=SSERd
+E: ID_TYPE=disk
+E: ID_VENDOR=SANVEND
+E: ID_WWN=0x600140500000000d
+E: MAJOR=8
+E: MINOR=0
+E: SUBSYSTEM=block
diff --git a/src/test/disk_tests/multipath/zpool b/src/test/disk_tests/multipath/zpool
new file mode 100644
index 0000000..e723f7e
--- /dev/null
+++ b/src/test/disk_tests/multipath/zpool
@@ -0,0 +1 @@
+	/dev/dm-3	-
diff --git a/src/test/disklist_test.pm b/src/test/disklist_test.pm
index a0dc01f..9e35430 100644
--- a/src/test/disklist_test.pm
+++ b/src/test/disklist_test.pm
@@ -18,6 +18,14 @@ my $testcount = 0; # testcount for TAP::Harness
 my $diskmanage_module; # mockmodule for PVE::Diskmanage
 my $print = 0;
 
+my $multipath_aliases = {
+    '/dev/mapper/mpatha' => '/dev/dm-0',
+    '/dev/mapper/mpathb' => '/dev/dm-1',
+    '/dev/mapper/mpathc' => '/dev/dm-2',
+    '/dev/mapper/mpathd' => '/dev/dm-3',
+    '/dev/mapper/mpathe' => '/dev/dm-4',
+};
+
 sub mocked_run_command {
     my ($cmd, %param) = @_;
 
@@ -101,6 +109,16 @@ sub mocked_is_iscsi {
     return 0;
 }
 
+sub mocked_file_read_firstline {
+    my ($path) = @_;
+
+    my $originalsub = $diskmanage_module->original('file_read_firstline');
+
+    $path =~ s|^/sys/block|disk_tests/$testcasedir|;
+
+    return &$originalsub($path);
+}
+
 sub mocked_dir_glob_foreach {
     my ($dir, $regex, $sub) = @_;
 
@@ -109,6 +127,8 @@ sub mocked_dir_glob_foreach {
     # read lines in from file
     if ($dir =~ m{^/sys/block$}) {
         @$lines = split(/\n/, read_test_file('disklist'));
+    } elsif ($dir =~ m{^/sys/block/([^/]+)/slaves$}) {
+        @$lines = split(/\n/, read_test_file("${1}_slaves"));
     } elsif ($dir =~ m{^/sys/block/([^/]+)}) {
         @$lines = split(/\n/, read_test_file('partlist'));
     }
@@ -213,6 +233,15 @@ sub test_disk_list {
         $testcount++;
         is_deeply($disks, $expected_disk_list, 'disk list should be the same');
 
+        if (-f "disk_tests/$testcasedir/multipath_expected.json") {
+            my $multipath = PVE::Diskmanage::get_multipath_disks();
+            my $expected_multipath = decode_json(read_test_file('multipath_expected.json'));
+
+            print Dumper($multipath) if $print;
+            $testcount++;
+            is_deeply($multipath, $expected_multipath, 'multipath list should be the same');
+        }
+
         done_testing($testcount);
     };
 }
@@ -239,8 +268,15 @@ $diskmanage_module->mock('assert_blockdev' => sub { return 1; });
 print("\tMocked assert_blockdev\n");
 $diskmanage_module->mock(
     'dir_is_empty' => sub {
-        # all partitions have a holder dir
         my $val = shift;
+        # let test cases provide the dir (e.g. holders) with content
+        my $mapped = $val;
+        $mapped =~ s|^/sys/block|disk_tests/$testcasedir|;
+        if (-d $mapped) {
+            my $originalsub = $diskmanage_module->original('dir_is_empty');
+            return &$originalsub($mapped);
+        }
+        # all partitions have a holder dir
         if ($val =~ m|^/sys/block/.+/.+/|) {
             return 0;
         }
@@ -248,6 +284,17 @@ $diskmanage_module->mock(
     },
 );
 print("\tMocked dir_is_empty\n");
+$diskmanage_module->mock('file_read_firstline' => \&mocked_file_read_firstline);
+print("\tMocked file_read_firstline\n");
+$diskmanage_module->mock(
+    'abs_path' => sub {
+        my ($path) = @_;
+        return $multipath_aliases->{$path}
+            if defined($multipath_aliases->{$path});
+        return &{ $diskmanage_module->original('abs_path') }($path);
+    },
+);
+print("\tMocked abs_path\n");
 $diskmanage_module->mock('check_bin' => sub { return 1; });
 print("\tMocked check_bin\n");
 my $tools_module = Test::MockModule->new('PVE::ProcFSTools', no_auto => 1);
-- 
2.47.3