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1 | [[storage_lvm]] | |
2 | LVM Backend | |
3 | ----------- | |
4 | ifdef::wiki[] | |
5 | :pve-toplevel: | |
6 | :title: Storage: LVM | |
7 | endif::wiki[] | |
8 | ||
9 | Storage pool type: `lvm` | |
10 | ||
11 | LVM is a light software layer on top of hard disks and partitions. It | |
12 | can be used to split available disk space into smaller logical | |
13 | volumes. LVM is widely used on Linux and makes managing hard drives | |
14 | easier. | |
15 | ||
16 | Another use case is to put LVM on top of a big iSCSI LUN. That way you | |
17 | can easily manage space on that iSCSI LUN, which would not be possible | |
18 | otherwise, because the iSCSI specification does not define a | |
19 | management interface for space allocation. | |
20 | ||
21 | ||
22 | Configuration | |
23 | ~~~~~~~~~~~~~ | |
24 | ||
25 | The LVM backend supports the common storage properties `content`, `nodes`, | |
26 | `disable`, and the following LVM specific properties: | |
27 | ||
28 | `vgname`:: | |
29 | ||
30 | LVM volume group name. This must point to an existing volume group. | |
31 | ||
32 | `base`:: | |
33 | ||
34 | Base volume. This volume is automatically activated before accessing | |
35 | the storage. This is mostly useful when the LVM volume group resides | |
36 | on a remote iSCSI server. | |
37 | ||
38 | `saferemove`:: | |
39 | ||
40 | Called "Wipe Removed Volumes" in the web UI. Zero-out data when removing LVs. | |
41 | When removing a volume, this makes sure that all data gets erased and cannot be | |
42 | accessed by other LVs created later (which happen to be assigned the same | |
43 | physical extents). This is a costly operation, but may be required as a security | |
44 | measure in certain environments. | |
45 | ||
46 | `saferemove_throughput`:: | |
47 | ||
48 | Wipe throughput (`cstream -t` parameter value). | |
49 | ||
50 | .Configuration Example (`/etc/pve/storage.cfg`) | |
51 | ---- | |
52 | lvm: myspace | |
53 | vgname myspace | |
54 | content rootdir,images | |
55 | ---- | |
56 | ||
57 | File naming conventions | |
58 | ~~~~~~~~~~~~~~~~~~~~~~~ | |
59 | ||
60 | The backend use basically the same naming conventions as the ZFS pool | |
61 | backend. | |
62 | ||
63 | vm-<VMID>-<NAME> // normal VM images | |
64 | ||
65 | Storage Features | |
66 | ~~~~~~~~~~~~~~~~ | |
67 | ||
68 | LVM is a typical block storage, but this backend does not support | |
69 | snapshots and clones. Unfortunately, normal LVM snapshots are quite | |
70 | inefficient, because they interfere with all writes on the entire volume | |
71 | group during snapshot time. | |
72 | ||
73 | One big advantage is that you can use it on top of a shared storage, | |
74 | for example, an iSCSI LUN. The backend itself implements proper cluster-wide | |
75 | locking. | |
76 | ||
77 | TIP: The newer LVM-thin backend allows snapshots and clones, but does | |
78 | not support shared storage. | |
79 | ||
80 | ||
81 | .Storage features for backend `lvm` | |
82 | [width="100%",cols="m,m,3*d",options="header"] | |
83 | |============================================================================== | |
84 | |Content types |Image formats |Shared |Snapshots |Clones | |
85 | |images rootdir |raw |possible |no |no | |
86 | |============================================================================== | |
87 | ||
88 | Examples | |
89 | ~~~~~~~~ | |
90 | ||
91 | List available volume groups: | |
92 | ||
93 | # pvesm lvmscan | |
94 | ||
95 | ifdef::wiki[] | |
96 | ||
97 | See Also | |
98 | ~~~~~~~~ | |
99 | ||
100 | * link:/wiki/Storage[Storage] | |
101 | ||
102 | endif::wiki[] | |
103 | ||
104 |