1containers-storage.conf(5)(Container)Filecontainers-storage.conf(5)(Container)
2Dan Walsh May 2017
6
9 storage.conf - Syntax of Container Storage configuration file
10
13 The STORAGE configuration file specifies all of the available container
14 storage options for tools using shared container storage, but in a TOML
15 format that can be more easily modified and versioned.
16
19 The [TOML format][toml] is used as the encoding of the configuration
20 file. Every option and subtable listed here is nested under a global
21 "storage" table. No bare options are used. The format of TOML can be
22 simplified to:
23 [table]
26 option = value
27 [table.subtable1]
29 option = value
30 [table.subtable2]
32 option = value
33
37 The storage table supports the following options:
38 driver=""
41 container storage driver (default: "overlay")
42 Default Copy On Write (COW) container storage driver. Valid drivers
43 are "overlay", "vfs", "devmapper", "aufs", "btrfs", and "zfs". Some
44 drivers (for example, "zfs", "btrfs", and "aufs") may not work if your
45 kernel lacks support for the filesystem.
46 graphroot=""
49 container storage graph dir (default: "/var/lib/containers/storage")
50 Default directory to store all writable content created by container
51 storage programs.
52 The rootless graphroot path supports environment variable substitu‐
53 tions (ie. $HOME/containers/storage)
54 rootless_storage_path="$HOME/.local/share/containers/storage"
57 Storage path for rootless users. By default the graphroot for root‐
58 less users
59 is set to $XDG_DATA_HOME/containers/storage, if XDG_DATA_HOME is set.
60 Otherwise $HOME/.local/share/containers/storage is used. This field
61 can
62 be used if administrators need to change the storage location for all
63 users.
64 The rootless storage path supports environment variable substitutions
65 (ie. $HOME/containers/storage)
66 A common use case for this field is to provide a local storage direc‐
69 tory when user home directories are NFS-mounted (podman does not sup‐
70 port container storage over NFS).
71 runroot=""
74 container storage run dir (default: "/var/run/containers/storage")
75 Default directory to store all temporary writable content created by
76 container storage programs.
77 The rootless runroot path supports environment variable substitutions
78 (ie. $HOME/containers/storage)
79 STORAGE OPTIONS TABLE
82 The storage.options table supports the following options:
83 additionalimagestores=[]
86 Paths to additional container image stores. Usually these are
87 read/only and stored on remote network shares.
88 remap-uids="" remap-gids=""
91 Remap-UIDs/GIDs is the mapping from UIDs/GIDs as they should appear
92 inside of a container, to the UIDs/GIDs outside of the container, and
93 the length of the range of UIDs/GIDs. Additional mapped sets can be
94 listed and will be heeded by libraries, but there are limits to the
95 number of mappings which the kernel will allow when you later attempt
96 to run a container.
97 Example
100 remap-uids = 0:1668442479:65536
101 remap-gids = 0:1668442479:65536
102 These mappings tell the container engines to map UID 0 inside of the
105 container to UID 1668442479 outside. UID 1 will be mapped to
106 1668442480. UID 2 will be mapped to 1668442481, etc, for the next 65533
107 UIDs in succession.
108 remap-user="" remap-group=""
111 Remap-User/Group is a user name which can be used to look up one or
112 more UID/GID ranges in the /etc/subuid or /etc/subgid file. Mappings
113 are set up starting with an in-container ID of 0 and then a host-level
114 ID taken from the lowest range that matches the specified name, and
115 using the length of that range. Additional ranges are then assigned,
116 using the ranges which specify the lowest host-level IDs first, to the
117 lowest not-yet-mapped in-container ID, until all of the entries have
118 been used for maps.
119 Example
122 remap-user = "containers"
123 remap-group = "containers"
124 root-auto-userns-user=""
127 Root-auto-userns-user is a user name which can be used to look up one
128 or more UID/GID ranges in the /etc/subuid and /etc/subgid file. These
129 ranges will be partitioned to containers configured to create automati‐
130 cally a user namespace. Containers configured to automatically create
131 a user namespace can still overlap with containers having an explicit
132 mapping set. This setting is ignored when running as rootless.
133 auto-userns-min-size=1024
136 Auto-userns-min-size is the minimum size for a user namespace created
137 automatically.
138 auto-userns-max-size=65536
141 Auto-userns-max-size is the maximum size for a user namespace created
142 automatically.
143 STORAGE OPTIONS FOR AUFS TABLE
146 The storage.options.aufs table supports the following options:
147 mountopt=""
150 Comma separated list of default options to be used to mount container
151 images. Suggested value "nodev". Mount options are documented in the
152 mount(8) man page.
153 STORAGE OPTIONS FOR BTRFS TABLE
156 The storage.options.btrfs table supports the following options:
157 min_space=""
160 Specifies the min space in a btrfs volume.
161 size=""
164 Maximum size of a container image. This flag can be used to set
165 quota on the size of container images. (format: [], where unit = b
166 (bytes), k (kilobytes), m (megabytes), or g (gigabytes))
167 STORAGE OPTIONS FOR THINPOOL (devicemapper) TABLE
170 The storage.options.thinpool table supports the following options for
171 the devicemapper driver:
172 autoextend_percent=""
175 Tells the thinpool driver the amount by which the thinpool needs to
176 be grown. This is specified in terms of % of pool size. So a value of
177 20 means that when threshold is hit, pool will be grown by 20% of
178 existing pool size. (default: 20%)
179 autoextend_threshold=""
182 Tells the driver the thinpool extension threshold in terms of per‐
183 centage of pool size. For example, if threshold is 60, that means when
184 pool is 60% full, threshold has been hit. (default: 80%)
185 basesize=""
188 Specifies the size to use when creating the base device, which limits
189 the size of images and containers. (default: 10g)
190 blocksize=""
193 Specifies a custom blocksize to use for the thin pool. (default: 64k)
194 directlvm_device=""
197 Specifies a custom block storage device to use for the thin pool.
198 Required for using graphdriver devicemapper.
199 directlvm_device_force=""
202 Tells driver to wipe device (directlvm_device) even if device already
203 has a filesystem. (default: false)
204 fs="xfs"
207 Specifies the filesystem type to use for the base device. (default:
208 xfs)
209 log_level=""
212 Sets the log level of devicemapper.
213 0: LogLevelSuppress 0 (default)
216 2: LogLevelFatal
217 3: LogLevelErr
218 4: LogLevelWarn
219 5: LogLevelNotice
220 6: LogLevelInfo
221 7: LogLevelDebug
222 metadata_size=""
226 metadata_size is used to set the pvcreate --metadatasize options when
227 creating thin devices. (Default 128k)
228 min_free_space=""
231 Specifies the min free space percent in a thin pool required for new
232 device creation to succeed. Valid values are from 0% - 99%. Value 0%
233 disables. (default: 10%)
234 mkfsarg=""
237 Specifies extra mkfs arguments to be used when creating the base
238 device.
239 mountopt=""
242 Comma separated list of default options to be used to mount container
243 images. Suggested value "nodev". Mount options are documented in the
244 mount(8) man page.
245 size=""
248 Maximum size of a container image. This flag can be used to set
249 quota on the size of container images. (format: [], where unit = b
250 (bytes), k (kilobytes), m (megabytes), or g (gigabytes))
251 use_deferred_deletion=""
254 Marks thinpool device for deferred deletion. If the thinpool is in
255 use when the driver attempts to delete it, the driver will attempt to
256 delete device every 30 seconds until successful, or when it restarts.
257 Deferred deletion permanently deletes the device and all data stored in
258 the device will be lost. (default: true).
259 use_deferred_removal=""
262 Marks devicemapper block device for deferred removal. If the device
263 is in use when its driver attempts to remove it, the driver tells the
264 kernel to remove the device as soon as possible. Note this does not
265 free up the disk space, use deferred deletion to fully remove the thin‐
266 pool. (default: true).
267 xfs_nospace_max_retries=""
270 Specifies the maximum number of retries XFS should attempt to com‐
271 plete IO when ENOSPC (no space) error is returned by underlying storage
272 device. (default: 0, which means to try continuously.)
273 STORAGE OPTIONS FOR OVERLAY TABLE
276 The storage.options.overlay table supports the following options:
277 ignore_chown_errors = "false"
280 ignore_chown_errors can be set to allow a non privileged user running
281 with a single UID within a user namespace to run containers. The user
282 can pull and use any image even those with multiple uids. Note multi‐
283 ple UIDs will be squashed down to the default uid in the container.
284 These images will have no separation between the users in the con‐
285 tainer. (default: false)
286 mount_program=""
289 Specifies the path to a custom program to use instead of using kernel
290 defaults for mounting the file system. In rootless mode, without the
291 CAP_SYS_ADMIN capability, many kernels prevent mounting of overlay file
292 systems, requiring you to specify a mount_program. The mount_program
293 option is also required on systems where the underlying storage is
294 btrfs, aufs, zfs, overlay, or ecryptfs based file systems.
295 mount_program = "/usr/bin/fuse-overlayfs"
296 mountopt=""
299 Comma separated list of default options to be used to mount container
300 images. Suggested value "nodev". Mount options are documented in the
301 mount(8) man page.
302 size=""
305 Maximum size of a container image. This flag can be used to set
306 quota on the size of container images. (format: [], where unit = b
307 (bytes), k (kilobytes), m (megabytes), or g (gigabytes))
308 STORAGE OPTIONS FOR VFS TABLE
311 The storage.options.vfs table supports the following options:
312 ignore_chown_errors = "false"
315 ignore_chown_errors can be set to allow a non privileged user running
316 with a single UID within a user namespace to run containers. The user
317 can pull and use any image even those with multiple uids. Note multi‐
318 ple UIDs will be squashed down to the default uid in the container.
319 These images will have no separation between the users in the con‐
320 tainer. (default: false)
321 STORAGE OPTIONS FOR ZFS TABLE
324 The storage.options.zfs table supports the following options:
325 fsname=""
328 File System name for the zfs driver
329 mountopt=""
332 Comma separated list of default options to be used to mount container
333 images. Suggested value "nodev". Mount options are documented in the
334 mount(8) man page.
335 skip_mount_home=""
338 Tell storage drivers to not create a PRIVATE bind mount on their home
339 directory.
340 size=""
343 Maximum size of a container image. This flag can be used to set
344 quota on the size of container images. (format: [], where unit = b
345 (bytes), k (kilobytes), m (megabytes), or g (gigabytes))
346
349 When running on an SELinux system, if you move the containers storage
350 graphroot directory, you must make sure the labeling is correct.
351 Tell SELinux about the new containers storage by setting up an equiva‐
354 lence record. This tells SELinux to label content under the new path,
355 as if it was stored under /var/lib/containers/storage.
356 semanage fcontext -a -e /var/lib/containers NEWSTORAGEPATH
359 restorecon -R -v NEWSTORAGEPATH
360 The semanage command above tells SELinux to setup the default labeling
364 of NEWSTORAGEPATH to match /var/lib/containers. The restorecon command
365 tells SELinux to apply the labels to the actual content.
366 Now all new content created in these directories will automatically be
369 created with the correct label.
370
373 semanage(8), restorecon(8), mount(8)
374
377 Distributions often provide a /usr/share/containers/storage.conf file
378 to define default storage configuration. Administrators can override
379 this file by creating /etc/containers/storage.conf to specify their own
380 configuration. The storage.conf file for rootless users is stored in
381 the $XDG_CONFIG_HOME/containers/storage.conf file. If $XDG_CONFIG_HOME
382 is not set then the file $HOME/.config/containers/storage.conf is used.
383
386 May 2017, Originally compiled by Dan Walsh dwalsh@redhat.com
387 ⟨mailto:dwalsh@redhat.com⟩ Format copied from crio.conf man page cre‐
388 ated by Aleksa Sarai asarai@suse.de ⟨mailto:asarai@suse.de⟩
389Configuration Storagceontainers-storage.conf(5)(Container)