mirror of https://github.com/docker/docs.git
Merge pull request #113 from mbentley/fix-devicemapper-docs
Fixed jekyll formatting for dm docs; fixed #112
This commit is contained in:
John Mulhausen
GitHub
commit
1357a4486d
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@ -194,7 +194,7 @@ Storage Driver: devicemapper
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Metadata loop file: /var/lib/docker/devicemapper/devicemapper/metadata
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Library Version: 1.02.93-RHEL7 (2015-01-28)
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[...]
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```
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```
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The output above shows a Docker host running with the `devicemapper` storage
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driver operating in `loop-lvm` mode. This is indicated by the fact that the
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@ -223,125 +223,126 @@ assumes that the Docker daemon is in the `stopped` state.
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1. Log in to the Docker host you want to configure and stop the Docker daemon.
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2. Install the LVM2 package.
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The LVM2 package includes the userspace toolset that provides logical volume
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management facilities on linux.
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The LVM2 package includes the userspace toolset that provides logical volume
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management facilities on linux.
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3. Create a physical volume replacing `/dev/xvdf` with your block device.
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```bash
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$ pvcreate /dev/xvdf
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```
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```bash
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$ pvcreate /dev/xvdf
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```
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4. Create a 'docker' volume group.
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```bash
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$ vgcreate docker /dev/xvdf
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```
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```bash
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$ vgcreate docker /dev/xvdf
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```
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5. Create a thin pool named `thinpool`.
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In this example, the data logical is 95% of the 'docker' volume group size.
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Leaving this free space allows for auto expanding of either the data or
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metadata if space runs low as a temporary stopgap.
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In this example, the data logical is 95% of the 'docker' volume group size.
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Leaving this free space allows for auto expanding of either the data or
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metadata if space runs low as a temporary stopgap.
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```bash
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$ lvcreate --wipesignatures y -n thinpool docker -l 95%VG
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$ lvcreate --wipesignatures y -n thinpoolmeta docker -l 1%VG
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```
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```bash
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$ lvcreate --wipesignatures y -n thinpool docker -l 95%VG
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$ lvcreate --wipesignatures y -n thinpoolmeta docker -l 1%VG
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```
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6. Convert the pool to a thin pool.
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```bash
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$ lvconvert -y --zero n -c 512K --thinpool docker/thinpool --poolmetadata docker/thinpoolmeta
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```
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```bash
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$ lvconvert -y --zero n -c 512K --thinpool docker/thinpool --poolmetadata docker/thinpoolmeta
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```
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7. Configure autoextension of thin pools via an `lvm` profile.
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```bash
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$ vi /etc/lvm/profile/docker-thinpool.profile
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```
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```bash
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$ vi /etc/lvm/profile/docker-thinpool.profile
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```
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8. Specify 'thin_pool_autoextend_threshold' value.
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8. Specify `thin_pool_autoextend_threshold` value.
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The value should be the percentage of space used before `lvm` attempts
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to autoextend the available space (100 = disabled).
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The value should be the percentage of space used before `lvm` attempts
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to autoextend the available space (100 = disabled).
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```
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thin_pool_autoextend_threshold = 80
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```
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```
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thin_pool_autoextend_threshold = 80
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```
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9. Modify the `thin_pool_autoextend_percent` for when thin pool autoextension occurs.
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The value's setting is the percentage of space to increase the thin pool (100 =
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disabled)
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The value's setting is the percentage of space to increase the thin pool (100 =
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disabled)
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```
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thin_pool_autoextend_percent = 20
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```
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```
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thin_pool_autoextend_percent = 20
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```
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10. Check your work, your `docker-thinpool.profile` file should appear similar to the following:
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An example `/etc/lvm/profile/docker-thinpool.profile` file:
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An example `/etc/lvm/profile/docker-thinpool.profile` file:
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```
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activation {
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thin_pool_autoextend_threshold=80
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thin_pool_autoextend_percent=20
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}
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```
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```
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activation {
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thin_pool_autoextend_threshold=80
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thin_pool_autoextend_percent=20
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}
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```
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11. Apply your new lvm profile
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```bash
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$ lvchange --metadataprofile docker-thinpool docker/thinpool
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```
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```bash
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$ lvchange --metadataprofile docker-thinpool docker/thinpool
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```
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12. Verify the `lv` is monitored.
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```bash
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$ lvs -o+seg_monitor
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```
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```bash
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$ lvs -o+seg_monitor
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```
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13. If the Docker daemon was previously started, clear your graph driver directory.
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Clearing your graph driver removes any images, containers, and volumes in your
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Docker installation.
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Clearing your graph driver removes any images, containers, and volumes in your
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Docker installation.
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```bash
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$ rm -rf /var/lib/docker/*
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```
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```bash
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$ rm -rf /var/lib/docker/*
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```
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14. Configure the Docker daemon with specific devicemapper options.
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There are two ways to do this. You can set options on the command line if you start the daemon there:
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There are two ways to do this. You can set options on the command line if you start the daemon there:
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```bash
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--storage-driver=devicemapper --storage-opt=dm.thinpooldev=/dev/mapper/docker-thinpool --storage-opt dm.use_deferred_removal=true
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```
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```bash
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--storage-driver=devicemapper --storage-opt=dm.thinpooldev=/dev/mapper/docker-thinpool --storage-opt dm.use_deferred_removal=true
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```
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You can also set them for startup in the `daemon.json` configuration, for example:
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You can also set them for startup in the `daemon.json` configuration, for example:
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```json
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{
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"storage-driver": "devicemapper",
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"storage-opts": [
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"dm.thinpooldev=/dev/mapper/docker-thinpool",
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"dm.use_deferred_removal=true"
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]
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}
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```
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```json
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{
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"storage-driver": "devicemapper",
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"storage-opts": [
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"dm.thinpooldev=/dev/mapper/docker-thinpool",
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"dm.use_deferred_removal=true"
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]
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}
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```
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15. If using systemd and modifying the daemon configuration via unit or drop-in file, reload systemd to scan for changes.
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```bash
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$ systemctl daemon-reload
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```
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```bash
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$ systemctl daemon-reload
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```
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16. Start the Docker daemon.
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```bash
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$ systemctl start docker
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```
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```bash
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$ systemctl start docker
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```
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After you start the Docker daemon, ensure you monitor your thin pool and volume
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group free space. While the volume group will auto-extend, it can still fill
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@ -453,79 +454,79 @@ The `Data Space` values show that the pool is 100GB total. This example extends
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1. List the sizes of the devices.
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```bash
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$ sudo ls -lh /var/lib/docker/devicemapper/devicemapper/
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```bash
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$ sudo ls -lh /var/lib/docker/devicemapper/devicemapper/
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total 1175492
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-rw------- 1 root root 100G Mar 30 05:22 data
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-rw------- 1 root root 2.0G Mar 31 11:17 metadata
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```
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total 1175492
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-rw------- 1 root root 100G Mar 30 05:22 data
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-rw------- 1 root root 2.0G Mar 31 11:17 metadata
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```
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2. Truncate `data` file to the size of the `metadata` file (approximage 200GB).
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```bash
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$ sudo truncate -s 214748364800 /var/lib/docker/devicemapper/devicemapper/data
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```
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```bash
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$ sudo truncate -s 214748364800 /var/lib/docker/devicemapper/devicemapper/data
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```
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3. Verify the file size changed.
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```bash
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$ sudo ls -lh /var/lib/docker/devicemapper/devicemapper/
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```bash
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$ sudo ls -lh /var/lib/docker/devicemapper/devicemapper/
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total 1.2G
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-rw------- 1 root root 200G Apr 14 08:47 data
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-rw------- 1 root root 2.0G Apr 19 13:27 metadata
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```
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total 1.2G
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-rw------- 1 root root 200G Apr 14 08:47 data
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-rw------- 1 root root 2.0G Apr 19 13:27 metadata
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```
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4. Reload data loop device
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```bash
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$ sudo blockdev --getsize64 /dev/loop0
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```bash
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$ sudo blockdev --getsize64 /dev/loop0
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107374182400
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107374182400
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$ sudo losetup -c /dev/loop0
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$ sudo losetup -c /dev/loop0
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$ sudo blockdev --getsize64 /dev/loop0
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$ sudo blockdev --getsize64 /dev/loop0
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214748364800
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```
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214748364800
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```
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5. Reload devicemapper thin pool.
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a. Get the pool name first.
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1. Get the pool name first.
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```bash
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$ sudo dmsetup status | grep pool
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```bash
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$ sudo dmsetup status | grep pool
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docker-8:1-123141-pool: 0 209715200 thin-pool 91
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422/524288 18338/1638400 - rw discard_passdown queue_if_no_space -
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```
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docker-8:1-123141-pool: 0 209715200 thin-pool 91
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422/524288 18338/1638400 - rw discard_passdown queue_if_no_space -
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```
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The name is the string before the colon.
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The name is the string before the colon.
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b. Dump the device mapper table first.
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2. Dump the device mapper table first.
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```bash
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$ sudo dmsetup table docker-8:1-123141-pool
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```bash
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$ sudo dmsetup table docker-8:1-123141-pool
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0 209715200 thin-pool 7:1 7:0 128 32768 1 skip_block_zeroing
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```
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0 209715200 thin-pool 7:1 7:0 128 32768 1 skip_block_zeroing
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```
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c. Calculate the real total sectors of the thin pool now.
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3. Calculate the real total sectors of the thin pool now.
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Change the second number of the table info (i.e. the disk end sector) to
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reflect the new number of 512 byte sectors in the disk. For example, as the
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new loop size is 200GB, change the second number to 419430400.
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Change the second number of the table info (i.e. the disk end sector) to
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reflect the new number of 512 byte sectors in the disk. For example, as the
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new loop size is 200GB, change the second number to 419430400.
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d. Reload the thin pool with the new sector number
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4. Reload the thin pool with the new sector number
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```bash
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$ sudo dmsetup suspend docker-8:1-123141-pool \
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&& sudo dmsetup reload docker-8:1-123141-pool --table '0 419430400 thin-pool 7:1 7:0 128 32768 1 skip_block_zeroing' \
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&& sudo dmsetup resume docker-8:1-123141-pool
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```
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```bash
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$ sudo dmsetup suspend docker-8:1-123141-pool \
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&& sudo dmsetup reload docker-8:1-123141-pool --table '0 419430400 thin-pool 7:1 7:0 128 32768 1 skip_block_zeroing' \
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&& sudo dmsetup resume docker-8:1-123141-pool
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```
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#### The device_tool
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@ -548,63 +549,64 @@ disk partition.
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1. Extend the volume group (VG) `vg-docker`.
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```bash
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$ sudo vgextend vg-docker /dev/sdh1
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```bash
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$ sudo vgextend vg-docker /dev/sdh1
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Volume group "vg-docker" successfully extended
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```
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Volume group "vg-docker" successfully extended
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```
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Your volume group may use a different name.
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Your volume group may use a different name.
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2. Extend the `data` logical volume(LV) `vg-docker/data`
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```bash
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$ sudo lvextend -l+100%FREE -n vg-docker/data
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```bash
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$ sudo lvextend -l+100%FREE -n vg-docker/data
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Extending logical volume data to 200 GiB
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Logical volume data successfully resized
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```
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Extending logical volume data to 200 GiB
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Logical volume data successfully resized
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```
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3. Reload devicemapper thin pool.
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a. Get the pool name.
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1. Get the pool name.
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```bash
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$ sudo dmsetup status | grep pool
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```bash
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$ sudo dmsetup status | grep pool
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docker-253:17-1835016-pool: 0 96460800 thin-pool 51593 6270/1048576 701943/753600 - rw no_discard_passdown queue_if_no_space
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```
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docker-253:17-1835016-pool: 0 96460800 thin-pool 51593 6270/1048576 701943/753600 - rw no_discard_passdown queue_if_no_space
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```
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The name is the string before the colon.
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The name is the string before the colon.
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b. Dump the device mapper table.
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2. Dump the device mapper table.
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```bash
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$ sudo dmsetup table docker-253:17-1835016-pool
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```bash
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$ sudo dmsetup table docker-253:17-1835016-pool
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0 96460800 thin-pool 252:0 252:1 128 32768 1 skip_block_zeroing
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```
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0 96460800 thin-pool 252:0 252:1 128 32768 1 skip_block_zeroing
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```
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c. Calculate the real total sectors of the thin pool now. we can use `blockdev` to get the real size of data lv.
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3. Calculate the real total sectors of the thin pool now. we can use `blockdev` to get the real size of data lv.
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Change the second number of the table info (i.e. the number of sectors) to
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reflect the new number of 512 byte sectors in the disk. For example, as the
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new data `lv` size is `264132100096` bytes, change the second number to
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`515883008`.
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Change the second number of the table info (i.e. the number of sectors) to
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reflect the new number of 512 byte sectors in the disk. For example, as the
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new data `lv` size is `264132100096` bytes, change the second number to
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`515883008`.
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```bash
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$ sudo blockdev --getsize64 /dev/vg-docker/data
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```bash
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$ sudo blockdev --getsize64 /dev/vg-docker/data
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264132100096
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```
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264132100096
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```
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d. Then reload the thin pool with the new sector number.
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4. Then reload the thin pool with the new sector number.
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```bash
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$ sudo dmsetup suspend docker-253:17-1835016-pool \
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&& sudo dmsetup reload docker-253:17-1835016-pool --table '0 515883008 thin-pool 252:0 252:1 128 32768 1 skip_block_zeroing' \
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&& sudo dmsetup resume docker-253:17-1835016-pool
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```
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```bash
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$ sudo dmsetup suspend docker-253:17-1835016-pool \
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&& sudo dmsetup reload docker-253:17-1835016-pool \
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--table '0 515883008 thin-pool 252:0 252:1 128 32768 1 skip_block_zeroing' \
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&& sudo dmsetup resume docker-253:17-1835016-pool
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```
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## Device Mapper and Docker performance
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue