User may also create clone of existing snapshot that will be thin provisioned and it will behave in the same way as logical volume from which snapshot is created.
There is no limit of clones and snapshots that may be created as long as there is enough space on logical volume store. Snapshots are read only. Clones may be created only from snapshots or read only logical volumes.
+A snapshot can be removed only if there is a single clone on top of it. The relation chain will be updated accordingly. The cluster map of clone and snapshot will be merged and entries for unallocated clusters in the clone
+will be updated with addresses from the snapshot cluster map. The entire operation modifies metadata only - no data is copied during this process.
+
## Inflation {#lvol_inflation}
Blobs can be inflated to copy data from backing devices (e.g. snapshots) and allocate all remaining clusters. As a result of this operation all dependencies for the blob are removed.
RPC regarding lvolstore:
```
-construct_lvol_store [-h] [-c CLUSTER_SZ] bdev_name lvs_name
+bdev_lvol_create_lvstore [-h] [-c CLUSTER_SZ] bdev_name lvs_name
Constructs lvolstore on specified bdev with specified name. During
construction bdev is unmapped at initialization and all data is
erased. Then original bdev is claimed by
-h show help
-c CLUSTER_SZ Specifies the size of cluster. By default its 4MiB.
--clear-method specify data region clear method "none", "unmap" (default), "write_zeroes"
-destroy_lvol_store [-h] [-u UUID] [-l LVS_NAME]
+bdev_lvol_delete_lvstore [-h] [-u UUID] [-l LVS_NAME]
Destroy lvolstore on specified bdev. Removes lvolstore along with lvols on
it. User can identify lvol store by UUID or its name. Note that destroying
lvolstore requires using this call, while deleting single lvol requires
- using destroy_lvol_bdev rpc call.
+ using bdev_lvol_delete rpc call.
optional arguments:
-h, --help show help
-get_lvol_stores [-h] [-u UUID] [-l LVS_NAME]
+bdev_lvol_get_lvstores [-h] [-u UUID] [-l LVS_NAME]
Display current logical volume store list
optional arguments:
-h, --help show help
-u UUID, --uuid UUID show details of specified lvol store
-l LVS_NAME, --lvs_name LVS_NAME show details of specified lvol store
-rename_lvol_store [-h] old_name new_name
+bdev_lvol_rename_lvstore [-h] old_name new_name
Change logical volume store name
optional arguments:
-h, --help show this help message and exit
RPC regarding lvol and spdk bdev:
```
-construct_lvol_bdev [-h] [-u UUID] [-l LVS_NAME] [-t] [-c CLEAR_METHOD] lvol_name size
+bdev_lvol_create [-h] [-u UUID] [-l LVS_NAME] [-t] [-c CLEAR_METHOD] lvol_name size
Creates lvol with specified size and name on lvolstore specified by its uuid
or name. Then constructs spdk bdev on top of that lvol and presents it as spdk bdev.
User may use -t switch to create thin provisioned lvol.
optional arguments:
-h, --help show help
-c, --clear-method specify data clusters clear method "none", "unmap" (default), "write_zeroes"
-get_bdevs [-h] [-b NAME]
+bdev_get_bdevs [-h] [-b NAME]
User can view created bdevs using this call including those created on top of lvols.
optional arguments:
-h, --help show help
-b NAME, --name NAME Name of the block device. Example: Nvme0n1
-destroy_lvol_bdev [-h] bdev_name
- Deletes a logical volume previously created by construct_lvol_bdev.
+bdev_lvol_delete [-h] bdev_name
+ Deletes a logical volume previously created by bdev_lvol_create.
optional arguments:
-h, --help show help
-snapshot_lvol_bdev [-h] lvol_name snapshot_name
+bdev_lvol_snapshot [-h] lvol_name snapshot_name
Create a snapshot with snapshot_name of a given lvol bdev.
optional arguments:
-h, --help show help
-clone_lvol_bdev [-h] snapshot_name clone_name
+bdev_lvol_clone [-h] snapshot_name clone_name
Create a clone with clone_name of a given lvol snapshot.
optional arguments:
-h, --help show help
-rename_lvol_bdev [-h] old_name new_name
+bdev_lvol_rename [-h] old_name new_name
Change lvol bdev name
optional arguments:
-h, --help show help
-resize_lvol_bdev [-h] name size
+bdev_lvol_resize [-h] name size
Resize existing lvol bdev
optional arguments:
-h, --help show help
-set_read_only_lvol_bdev [-h] name
+bdev_lvol_set_read_only [-h] name
Mark lvol bdev as read only
optional arguments:
-h, --help show help
-inflate_lvol_bdev [-h] name
+bdev_lvol_inflate [-h] name
Inflate lvol bdev
optional arguments:
-h, --help show help
-decouple_parent_lvol_bdev [-h] name
+bdev_lvol_decouple_parent [-h] name
Decouple parent of a logical volume
optional arguments:
-h, --help show help