1containers-storage.conf(5) May 2017 containers-storage.conf(5)
2
6 storage.conf - Syntax of Container Storage configuration file
7
10 The STORAGE configuration file specifies all of the available container
11 storage options for tools using shared container storage, but in a TOML
12 format that can be more easily modified and versioned.
13
16 The [TOML format][toml] is used as the encoding of the configuration
17 file. Every option and subtable listed here is nested under a global
18 "storage" table. No bare options are used. The format of TOML can be
19 simplified to:
20 [table]
23 option = value
24 [table.subtable1]
26 option = value
27 [table.subtable2]
29 option = value
30
34 The storage table supports the following options:
35 driver=""
38 container storage driver (default: "overlay")
39 Default Copy On Write (COW) container storage driver
40 Valid drivers are "overlay", "vfs", "devmapper", "aufs", "btrfs", and
41 "zfs"
42 Some drivers (for example, "zfs", "btrfs", and "aufs") may not work
43 if your kernel lacks support for the filesystem
44 graphroot=""
47 container storage graph dir (default: "/var/lib/containers/storage")
48 Default directory to store all writable content created by container
49 storage programs
50 runroot=""
53 container storage run dir (default: "/var/run/containers/storage")
54 Default directory to store all temporary writable content created by
55 container storage programs
56 STORAGE OPTIONS TABLE
59 The storage.options table supports the following options:
60 additionalimagestores=[]
63 Paths to additional container image stores. Usually these are
64 read/only and stored on remote network shares.
65 mount_program=""
68 Specifies the path to a custom program to use instead of using kernel
69 defaults for mounting the file system.
70 mount_program = "/usr/bin/fuse-overlayfs"
73 mountopt=""
77 Comma separated list of default options to be used to mount container
80 images. Suggested value "nodev".
81 ostree_repo = ""
84 If specified, use OSTree to deduplicate files with the overlay or
85 vfs backends.
86 size=""
89 Maximum size of a container image. This flag can be used to set
90 quota on the size of container images. (default: 10GB)
91 skip_mount_home = "false"
94 Set to skip a PRIVATE bind mount on the storage home directory.
95 Only supported by certain container storage drivers (overlay).
96 remap-uids="" remap-gids=""
99 Remap-UIDs/GIDs is the mapping from UIDs/GIDs as they should appear
102 inside of a container, to the UIDs/GIDs outside of the container, and
103 the length of the range of UIDs/GIDs. Additional mapped sets can be
104 listed and will be heeded by libraries, but there are limits to the
105 number of mappings which the kernel will allow when you later attempt
106 to run a container.
107 Example
110 remap-uids = 0:1668442479:65536
111 remap-gids = 0:1668442479:65536
112 These mappings tell the container engines to map UID 0 inside of the
114 container to UID 1668442479 outside. UID 1 will be mapped to 1668442480.
115 UID 2 will be mapped to 1668442481, etc, for the next 65533 UIDs in
116 Succession.
117 remap-user="" remap-group=""
121 Remap-User/Group is a user name which can be used to look up one or
124 more UID/GID ranges in the /etc/subuid or /etc/subgid file. Mappings
125 are set up starting with an in-container ID of 0 and then a host-level
126 ID taken from the lowest range that matches the specified name, and
127 using the length of that range. Additional ranges are then assigned,
128 using the ranges which specify the lowest host-level IDs first, to the
129 lowest not-yet-mapped in-container ID, until all of the entries have
130 been used for maps.
131 remap-user = "storage"
134 remap-group = "storage"
135 STORAGE OPTIONS FOR THINPOOL TABLE
139 The storage.options.thinpool table supports the following options:
140 autoextend_percent=""
143 Tells the thinpool driver the amount by which the thinpool needs to be
146 grown. This is specified in terms of % of pool size. So a value of 20
147 means that when threshold is hit, pool will be grown by 20% of existing
148 pool size. (default: 20%)
149 autoextend_threshold=""
152 Tells the driver the thinpool extension threshold in terms of
155 percentage of pool size. For example, if threshold is 60, that means
156 when pool is 60% full, threshold has been hit. (default: 80%)
157 basesize=""
160 Specifies the size to use when creating the base device, which limits
163 the size of images and containers. (default: 10g)
164 blocksize=""
167 Specifies a custom blocksize to use for the thin pool. (default: 64k)
170 directlvm_device=""
173 Specifies a custom block storage device to use for the thin pool.
176 Required for using graphdriver devicemapper.
177 directlvm_device_force=""
180 Tells driver to wipe device (directlvm_device) even if device already
183 has a filesystem. (default: false)
184 fs="xfs"
187 Specifies the filesystem type to use for the base device. (default:
190 xfs)
191 log_level=""
194 Sets the log level of devicemapper.
197 0: LogLevelSuppress 0 (default)
200 2: LogLevelFatal
201 3: LogLevelErr
202 4: LogLevelWarn
203 5: LogLevelNotice
204 6: LogLevelInfo
205 7: LogLevelDebug
206 min_free_space=""
210 Specifies the min free space percent in a thin pool required for new
213 device creation to succeed. Valid values are from 0% - 99%. Value 0%
214 disables. (default: 10%)
215 mkfsarg=""
218 Specifies extra mkfs arguments to be used when creating the base
221 device.
222 use_deferred_deletion=""
225 Marks thinpool device for deferred deletion. If the thinpool is in use
228 when the driver attempts to delete it, the driver will attempt to
229 delete device every 30 seconds until successful, or when it restarts.
230 Deferred deletion permanently deletes the device and all data stored in
231 the device will be lost. (default: true).
232 use_deferred_removal=""
235 Marks devicemapper block device for deferred removal. If the device is
238 in use when its driver attempts to remove it, the driver tells the
239 kernel to remove the device as soon as possible. Note this does not
240 free up the disk space, use deferred deletion to fully remove the
241 thinpool. (default: true).
242 xfs_nospace_max_retries=""
245 Specifies the maximum number of retries XFS should attempt to complete
248 IO when ENOSPC (no space) error is returned by underlying storage
249 device. (default: 0, which means to try continuously.)
250
253 When running on an SELinux system, if you move the containers storage
254 graphroot directory, you must make sure the labeling is correct.
255 Tell SELinux about the new containers storage by setting up an
258 equivalence record. This tells SELinux to label content under the new
259 path, as if it was stored under /var/lib/containers/storage.
260 semanage fcontext -a -e /var/lib/containers NEWSTORAGEPATH
263 restorecon -R -v /src/containers
264 The semanage command above tells SELinux to setup the default labeling
268 of NEWSTORAGEPATH to match /var/lib/containers. The restorecon command
269 tells SELinux to apply the labels to the actual content.
270 Now all new content created in these directories will automatically be
273 created with the correct label.
274
277 semanage(8), restorecon(8)
278
281 Distributions often provide a /usr/share/containers/storage.conf file
282 to define default storage configuration. Administrators can override
283 this file by creating /etc/containers/storage.conf to specify their own
284 configuration. The storage.conf file for rootless users is stored in
285 the $HOME/.config/containers/storage.conf file.
286
289 May 2017, Originally compiled by Dan Walsh ⟨dwalsh@redhat.com⟩ Format
290 copied from crio.conf man page created by Aleksa Sarai ⟨asarai@suse.de⟩
291Dan Walsh Container Storage ConfigurationcoFnitlaeiners-storage.conf(5)