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80c0adcb | 1 | [[chapter_pveceph]] |
0840a663 | 2 | ifdef::manvolnum[] |
b2f242ab DM |
3 | pveceph(1) |
4 | ========== | |
404a158e | 5 | :pve-toplevel: |
0840a663 DM |
6 | |
7 | NAME | |
8 | ---- | |
9 | ||
21394e70 | 10 | pveceph - Manage Ceph Services on Proxmox VE Nodes |
0840a663 | 11 | |
49a5e11c | 12 | SYNOPSIS |
0840a663 DM |
13 | -------- |
14 | ||
15 | include::pveceph.1-synopsis.adoc[] | |
16 | ||
17 | DESCRIPTION | |
18 | ----------- | |
19 | endif::manvolnum[] | |
0840a663 | 20 | ifndef::manvolnum[] |
4bfe3e35 TL |
21 | Deploy Hyper-Converged Ceph Cluster |
22 | =================================== | |
49d3ad91 | 23 | :pve-toplevel: |
0840a663 DM |
24 | endif::manvolnum[] |
25 | ||
1ff5e4e8 | 26 | [thumbnail="screenshot/gui-ceph-status.png"] |
8997dd6e | 27 | |
a474ca1f AA |
28 | {pve} unifies your compute and storage systems, i.e. you can use the same |
29 | physical nodes within a cluster for both computing (processing VMs and | |
30 | containers) and replicated storage. The traditional silos of compute and | |
31 | storage resources can be wrapped up into a single hyper-converged appliance. | |
32 | Separate storage networks (SANs) and connections via network attached storages | |
33 | (NAS) disappear. With the integration of Ceph, an open source software-defined | |
34 | storage platform, {pve} has the ability to run and manage Ceph storage directly | |
35 | on the hypervisor nodes. | |
c994e4e5 DM |
36 | |
37 | Ceph is a distributed object store and file system designed to provide | |
1d54c3b4 AA |
38 | excellent performance, reliability and scalability. |
39 | ||
04ba9b24 TL |
40 | .Some advantages of Ceph on {pve} are: |
41 | - Easy setup and management with CLI and GUI support | |
a474ca1f AA |
42 | - Thin provisioning |
43 | - Snapshots support | |
44 | - Self healing | |
a474ca1f AA |
45 | - Scalable to the exabyte level |
46 | - Setup pools with different performance and redundancy characteristics | |
47 | - Data is replicated, making it fault tolerant | |
48 | - Runs on economical commodity hardware | |
49 | - No need for hardware RAID controllers | |
a474ca1f AA |
50 | - Open source |
51 | ||
1d54c3b4 AA |
52 | For small to mid sized deployments, it is possible to install a Ceph server for |
53 | RADOS Block Devices (RBD) directly on your {pve} cluster nodes, see | |
c994e4e5 DM |
54 | xref:ceph_rados_block_devices[Ceph RADOS Block Devices (RBD)]. Recent |
55 | hardware has plenty of CPU power and RAM, so running storage services | |
56 | and VMs on the same node is possible. | |
21394e70 DM |
57 | |
58 | To simplify management, we provide 'pveceph' - a tool to install and | |
59 | manage {ceph} services on {pve} nodes. | |
60 | ||
2798d126 | 61 | .Ceph consists of a couple of Daemons footnote:[Ceph intro https://docs.ceph.com/docs/{ceph_codename}/start/intro/], for use as a RBD storage: |
1d54c3b4 AA |
62 | - Ceph Monitor (ceph-mon) |
63 | - Ceph Manager (ceph-mgr) | |
64 | - Ceph OSD (ceph-osd; Object Storage Daemon) | |
65 | ||
477fbcfb | 66 | TIP: We highly recommend to get familiar with Ceph's architecture |
2798d126 | 67 | footnote:[Ceph architecture https://docs.ceph.com/docs/{ceph_codename}/architecture/] |
477fbcfb | 68 | and vocabulary |
2798d126 | 69 | footnote:[Ceph glossary https://docs.ceph.com/docs/{ceph_codename}/glossary]. |
1d54c3b4 | 70 | |
21394e70 DM |
71 | |
72 | Precondition | |
73 | ------------ | |
74 | ||
76f6eca4 AA |
75 | To build a hyper-converged Proxmox + Ceph Cluster there should be at least |
76 | three (preferably) identical servers for the setup. | |
21394e70 DM |
77 | |
78 | Check also the recommendations from | |
2798d126 | 79 | https://docs.ceph.com/docs/{ceph_codename}/start/hardware-recommendations/[Ceph's website]. |
21394e70 | 80 | |
76f6eca4 | 81 | .CPU |
2f19a6b0 TL |
82 | Higher CPU core frequency reduce latency and should be preferred. As a simple |
83 | rule of thumb, you should assign a CPU core (or thread) to each Ceph service to | |
84 | provide enough resources for stable and durable Ceph performance. | |
76f6eca4 AA |
85 | |
86 | .Memory | |
87 | Especially in a hyper-converged setup, the memory consumption needs to be | |
2f19a6b0 | 88 | carefully monitored. In addition to the intended workload from virtual machines |
5b502340 AA |
89 | and containers, Ceph needs enough memory available to provide excellent and |
90 | stable performance. | |
91 | ||
92 | As a rule of thumb, for roughly **1 TiB of data, 1 GiB of memory** will be used | |
93 | by an OSD. Especially during recovery, rebalancing or backfilling. | |
94 | ||
95 | The daemon itself will use additional memory. The Bluestore backend of the | |
96 | daemon requires by default **3-5 GiB of memory** (adjustable). In contrast, the | |
97 | legacy Filestore backend uses the OS page cache and the memory consumption is | |
98 | generally related to PGs of an OSD daemon. | |
76f6eca4 AA |
99 | |
100 | .Network | |
101 | We recommend a network bandwidth of at least 10 GbE or more, which is used | |
102 | exclusively for Ceph. A meshed network setup | |
103 | footnote:[Full Mesh Network for Ceph {webwiki-url}Full_Mesh_Network_for_Ceph_Server] | |
104 | is also an option if there are no 10 GbE switches available. | |
105 | ||
2f19a6b0 TL |
106 | The volume of traffic, especially during recovery, will interfere with other |
107 | services on the same network and may even break the {pve} cluster stack. | |
76f6eca4 AA |
108 | |
109 | Further, estimate your bandwidth needs. While one HDD might not saturate a 1 Gb | |
2f19a6b0 | 110 | link, multiple HDD OSDs per node can, and modern NVMe SSDs will even saturate |
5f318cc0 | 111 | 10 Gbps of bandwidth quickly. Deploying a network capable of even more bandwidth |
2f19a6b0 TL |
112 | will ensure that it isn't your bottleneck and won't be anytime soon, 25, 40 or |
113 | even 100 GBps are possible. | |
76f6eca4 AA |
114 | |
115 | .Disks | |
116 | When planning the size of your Ceph cluster, it is important to take the | |
117 | recovery time into consideration. Especially with small clusters, the recovery | |
118 | might take long. It is recommended that you use SSDs instead of HDDs in small | |
119 | setups to reduce recovery time, minimizing the likelihood of a subsequent | |
120 | failure event during recovery. | |
121 | ||
2f19a6b0 | 122 | In general SSDs will provide more IOPs than spinning disks. This fact and the |
76f6eca4 | 123 | higher cost may make a xref:pve_ceph_device_classes[class based] separation of |
2f19a6b0 | 124 | pools appealing. Another possibility to speedup OSDs is to use a faster disk |
352c803f TL |
125 | as journal or DB/**W**rite-**A**head-**L**og device, see |
126 | xref:pve_ceph_osds[creating Ceph OSDs]. If a faster disk is used for multiple | |
127 | OSDs, a proper balance between OSD and WAL / DB (or journal) disk must be | |
128 | selected, otherwise the faster disk becomes the bottleneck for all linked OSDs. | |
76f6eca4 AA |
129 | |
130 | Aside from the disk type, Ceph best performs with an even sized and distributed | |
2f19a6b0 TL |
131 | amount of disks per node. For example, 4 x 500 GB disks with in each node is |
132 | better than a mixed setup with a single 1 TB and three 250 GB disk. | |
133 | ||
134 | One also need to balance OSD count and single OSD capacity. More capacity | |
135 | allows to increase storage density, but it also means that a single OSD | |
136 | failure forces ceph to recover more data at once. | |
76f6eca4 | 137 | |
a474ca1f | 138 | .Avoid RAID |
86be506d | 139 | As Ceph handles data object redundancy and multiple parallel writes to disks |
c78756be | 140 | (OSDs) on its own, using a RAID controller normally doesn’t improve |
86be506d TL |
141 | performance or availability. On the contrary, Ceph is designed to handle whole |
142 | disks on it's own, without any abstraction in between. RAID controller are not | |
143 | designed for the Ceph use case and may complicate things and sometimes even | |
144 | reduce performance, as their write and caching algorithms may interfere with | |
145 | the ones from Ceph. | |
a474ca1f AA |
146 | |
147 | WARNING: Avoid RAID controller, use host bus adapter (HBA) instead. | |
148 | ||
76f6eca4 | 149 | NOTE: Above recommendations should be seen as a rough guidance for choosing |
2f19a6b0 TL |
150 | hardware. Therefore, it is still essential to adapt it to your specific needs, |
151 | test your setup and monitor health and performance continuously. | |
76f6eca4 | 152 | |
2394c306 TM |
153 | [[pve_ceph_install_wizard]] |
154 | Initial Ceph installation & configuration | |
155 | ----------------------------------------- | |
156 | ||
157 | [thumbnail="screenshot/gui-node-ceph-install.png"] | |
158 | ||
159 | With {pve} you have the benefit of an easy to use installation wizard | |
160 | for Ceph. Click on one of your cluster nodes and navigate to the Ceph | |
6a711e64 TL |
161 | section in the menu tree. If Ceph is not already installed you will be |
162 | offered to do so now. | |
2394c306 TM |
163 | |
164 | The wizard is divided into different sections, where each needs to be | |
6a711e64 TL |
165 | finished successfully in order to use Ceph. After starting the installation |
166 | the wizard will download and install all required packages from {pve}'s ceph | |
167 | repository. | |
2394c306 TM |
168 | |
169 | After finishing the first step, you will need to create a configuration. | |
6a711e64 TL |
170 | This step is only needed once per cluster, as this configuration is distributed |
171 | automatically to all remaining cluster members through {pve}'s clustered | |
172 | xref:chapter_pmxcfs[configuration file system (pmxcfs)]. | |
2394c306 TM |
173 | |
174 | The configuration step includes the following settings: | |
175 | ||
176 | * *Public Network:* You should setup a dedicated network for Ceph, this | |
177 | setting is required. Separating your Ceph traffic is highly recommended, | |
6a711e64 TL |
178 | because it could lead to troubles with other latency dependent services, |
179 | e.g., cluster communication may decrease Ceph's performance, if not done. | |
2394c306 TM |
180 | |
181 | [thumbnail="screenshot/gui-node-ceph-install-wizard-step2.png"] | |
182 | ||
183 | * *Cluster Network:* As an optional step you can go even further and | |
184 | separate the xref:pve_ceph_osds[OSD] replication & heartbeat traffic | |
185 | as well. This will relieve the public network and could lead to | |
186 | significant performance improvements especially in big clusters. | |
187 | ||
188 | You have two more options which are considered advanced and therefore | |
189 | should only changed if you are an expert. | |
190 | ||
191 | * *Number of replicas*: Defines the how often a object is replicated | |
192 | * *Minimum replicas*: Defines the minimum number of required replicas | |
6a711e64 | 193 | for I/O to be marked as complete. |
2394c306 | 194 | |
6a711e64 | 195 | Additionally you need to choose your first monitor node, this is required. |
2394c306 TM |
196 | |
197 | That's it, you should see a success page as the last step with further | |
198 | instructions on how to go on. You are now prepared to start using Ceph, | |
199 | even though you will need to create additional xref:pve_ceph_monitors[monitors], | |
200 | create some xref:pve_ceph_osds[OSDs] and at least one xref:pve_ceph_pools[pool]. | |
201 | ||
202 | The rest of this chapter will guide you on how to get the most out of | |
203 | your {pve} based Ceph setup, this will include aforementioned and | |
204 | more like xref:pveceph_fs[CephFS] which is a very handy addition to your | |
205 | new Ceph cluster. | |
21394e70 | 206 | |
58f95dd7 | 207 | [[pve_ceph_install]] |
21394e70 DM |
208 | Installation of Ceph Packages |
209 | ----------------------------- | |
2394c306 TM |
210 | Use {pve} Ceph installation wizard (recommended) or run the following |
211 | command on each node: | |
21394e70 DM |
212 | |
213 | [source,bash] | |
214 | ---- | |
19920184 | 215 | pveceph install |
21394e70 DM |
216 | ---- |
217 | ||
218 | This sets up an `apt` package repository in | |
219 | `/etc/apt/sources.list.d/ceph.list` and installs the required software. | |
220 | ||
221 | ||
b3338e29 AA |
222 | Create initial Ceph configuration |
223 | --------------------------------- | |
21394e70 | 224 | |
1ff5e4e8 | 225 | [thumbnail="screenshot/gui-ceph-config.png"] |
8997dd6e | 226 | |
2394c306 TM |
227 | Use the {pve} Ceph installation wizard (recommended) or run the |
228 | following command on one node: | |
21394e70 DM |
229 | |
230 | [source,bash] | |
231 | ---- | |
232 | pveceph init --network 10.10.10.0/24 | |
233 | ---- | |
234 | ||
2394c306 TM |
235 | This creates an initial configuration at `/etc/pve/ceph.conf` with a |
236 | dedicated network for ceph. That file is automatically distributed to | |
237 | all {pve} nodes by using xref:chapter_pmxcfs[pmxcfs]. The command also | |
238 | creates a symbolic link from `/etc/ceph/ceph.conf` pointing to that file. | |
239 | So you can simply run Ceph commands without the need to specify a | |
240 | configuration file. | |
21394e70 DM |
241 | |
242 | ||
d9a27ee1 | 243 | [[pve_ceph_monitors]] |
b3338e29 AA |
244 | Ceph Monitor |
245 | ----------- | |
1d54c3b4 | 246 | The Ceph Monitor (MON) |
2798d126 | 247 | footnote:[Ceph Monitor https://docs.ceph.com/docs/{ceph_codename}/start/intro/] |
a474ca1f | 248 | maintains a master copy of the cluster map. For high availability you need to |
2394c306 | 249 | have at least 3 monitors. One monitor will already be installed if you |
620d6725 | 250 | used the installation wizard. You won't need more than 3 monitors as long |
2394c306 TM |
251 | as your cluster is small to midsize, only really large clusters will |
252 | need more than that. | |
1d54c3b4 | 253 | |
b3338e29 | 254 | |
c998bdf2 | 255 | [[pveceph_create_mon]] |
b3338e29 AA |
256 | Create Monitors |
257 | ~~~~~~~~~~~~~~~ | |
258 | ||
259 | [thumbnail="screenshot/gui-ceph-monitor.png"] | |
260 | ||
1d54c3b4 AA |
261 | On each node where you want to place a monitor (three monitors are recommended), |
262 | create it by using the 'Ceph -> Monitor' tab in the GUI or run. | |
21394e70 DM |
263 | |
264 | ||
265 | [source,bash] | |
266 | ---- | |
d1fdb121 | 267 | pveceph mon create |
21394e70 DM |
268 | ---- |
269 | ||
c998bdf2 | 270 | [[pveceph_destroy_mon]] |
b3338e29 AA |
271 | Destroy Monitors |
272 | ~~~~~~~~~~~~~~~~ | |
0e38a564 AA |
273 | |
274 | To remove a Ceph Monitor via the GUI first select a node in the tree view and | |
275 | go to the **Ceph -> Monitor** panel. Select the MON and click the **Destroy** | |
276 | button. | |
277 | ||
278 | To remove a Ceph Monitor via the CLI first connect to the node on which the MON | |
279 | is running. Then execute the following command: | |
280 | [source,bash] | |
281 | ---- | |
282 | pveceph mon destroy | |
283 | ---- | |
284 | ||
285 | NOTE: At least three Monitors are needed for quorum. | |
286 | ||
287 | ||
1d54c3b4 | 288 | [[pve_ceph_manager]] |
b3338e29 AA |
289 | Ceph Manager |
290 | ------------ | |
291 | The Manager daemon runs alongside the monitors. It provides an interface to | |
292 | monitor the cluster. Since the Ceph luminous release at least one ceph-mgr | |
2798d126 | 293 | footnote:[Ceph Manager https://docs.ceph.com/docs/{ceph_codename}/mgr/] daemon is |
b3338e29 AA |
294 | required. |
295 | ||
55d634e6 | 296 | [[pveceph_create_mgr]] |
b3338e29 AA |
297 | Create Manager |
298 | ~~~~~~~~~~~~~~ | |
1d54c3b4 | 299 | |
b3338e29 | 300 | Multiple Managers can be installed, but at any time only one Manager is active. |
1d54c3b4 | 301 | |
1d54c3b4 AA |
302 | [source,bash] |
303 | ---- | |
d1fdb121 | 304 | pveceph mgr create |
1d54c3b4 AA |
305 | ---- |
306 | ||
c1f38fe3 AA |
307 | NOTE: It is recommended to install the Ceph Manager on the monitor nodes. For |
308 | high availability install more then one manager. | |
309 | ||
21394e70 | 310 | |
c998bdf2 | 311 | [[pveceph_destroy_mgr]] |
b3338e29 AA |
312 | Destroy Manager |
313 | ~~~~~~~~~~~~~~~ | |
549350fe AA |
314 | |
315 | To remove a Ceph Manager via the GUI first select a node in the tree view and | |
316 | go to the **Ceph -> Monitor** panel. Select the Manager and click the | |
317 | **Destroy** button. | |
318 | ||
319 | To remove a Ceph Monitor via the CLI first connect to the node on which the | |
320 | Manager is running. Then execute the following command: | |
321 | [source,bash] | |
322 | ---- | |
323 | pveceph mgr destroy | |
324 | ---- | |
325 | ||
326 | NOTE: A Ceph cluster can function without a Manager, but certain functions like | |
327 | the cluster status or usage require a running Manager. | |
328 | ||
329 | ||
d9a27ee1 | 330 | [[pve_ceph_osds]] |
b3338e29 AA |
331 | Ceph OSDs |
332 | --------- | |
333 | Ceph **O**bject **S**torage **D**aemons are storing objects for Ceph over the | |
334 | network. It is recommended to use one OSD per physical disk. | |
335 | ||
336 | NOTE: By default an object is 4 MiB in size. | |
337 | ||
081cb761 | 338 | [[pve_ceph_osd_create]] |
b3338e29 AA |
339 | Create OSDs |
340 | ~~~~~~~~~~~ | |
21394e70 | 341 | |
1ff5e4e8 | 342 | [thumbnail="screenshot/gui-ceph-osd-status.png"] |
8997dd6e | 343 | |
21394e70 DM |
344 | via GUI or via CLI as follows: |
345 | ||
346 | [source,bash] | |
347 | ---- | |
d1fdb121 | 348 | pveceph osd create /dev/sd[X] |
21394e70 DM |
349 | ---- |
350 | ||
b3338e29 AA |
351 | TIP: We recommend a Ceph cluster size, starting with 12 OSDs, distributed |
352 | evenly among your, at least three nodes (4 OSDs on each node). | |
1d54c3b4 | 353 | |
a474ca1f | 354 | If the disk was used before (eg. ZFS/RAID/OSD), to remove partition table, boot |
9bddef40 | 355 | sector and any OSD leftover the following command should be sufficient. |
a474ca1f AA |
356 | |
357 | [source,bash] | |
358 | ---- | |
9bddef40 | 359 | ceph-volume lvm zap /dev/sd[X] --destroy |
a474ca1f AA |
360 | ---- |
361 | ||
9bddef40 | 362 | WARNING: The above command will destroy data on the disk! |
1d54c3b4 | 363 | |
b3338e29 | 364 | .Ceph Bluestore |
21394e70 | 365 | |
1d54c3b4 AA |
366 | Starting with the Ceph Kraken release, a new Ceph OSD storage type was |
367 | introduced, the so called Bluestore | |
2798d126 | 368 | footnote:[Ceph Bluestore https://ceph.com/community/new-luminous-bluestore/]. |
9bddef40 | 369 | This is the default when creating OSDs since Ceph Luminous. |
21394e70 DM |
370 | |
371 | [source,bash] | |
372 | ---- | |
d1fdb121 | 373 | pveceph osd create /dev/sd[X] |
1d54c3b4 AA |
374 | ---- |
375 | ||
1e834cb2 | 376 | .Block.db and block.wal |
1d54c3b4 AA |
377 | |
378 | If you want to use a separate DB/WAL device for your OSDs, you can specify it | |
b3338e29 AA |
379 | through the '-db_dev' and '-wal_dev' options. The WAL is placed with the DB, if |
380 | not specified separately. | |
1d54c3b4 AA |
381 | |
382 | [source,bash] | |
383 | ---- | |
d1fdb121 | 384 | pveceph osd create /dev/sd[X] -db_dev /dev/sd[Y] -wal_dev /dev/sd[Z] |
1d54c3b4 AA |
385 | ---- |
386 | ||
9bddef40 | 387 | You can directly choose the size for those with the '-db_size' and '-wal_size' |
5f318cc0 | 388 | parameters respectively. If they are not given the following values (in order) |
9bddef40 DC |
389 | will be used: |
390 | ||
352c803f TL |
391 | * bluestore_block_{db,wal}_size from ceph configuration... |
392 | ** ... database, section 'osd' | |
393 | ** ... database, section 'global' | |
394 | ** ... file, section 'osd' | |
395 | ** ... file, section 'global' | |
9bddef40 DC |
396 | * 10% (DB)/1% (WAL) of OSD size |
397 | ||
1d54c3b4 | 398 | NOTE: The DB stores BlueStore’s internal metadata and the WAL is BlueStore’s |
ee4a0e96 | 399 | internal journal or write-ahead log. It is recommended to use a fast SSD or |
1d54c3b4 AA |
400 | NVRAM for better performance. |
401 | ||
402 | ||
b3338e29 | 403 | .Ceph Filestore |
9bddef40 | 404 | |
352c803f | 405 | Before Ceph Luminous, Filestore was used as default storage type for Ceph OSDs. |
9bddef40 | 406 | Starting with Ceph Nautilus, {pve} does not support creating such OSDs with |
352c803f TL |
407 | 'pveceph' anymore. If you still want to create filestore OSDs, use |
408 | 'ceph-volume' directly. | |
1d54c3b4 AA |
409 | |
410 | [source,bash] | |
411 | ---- | |
9bddef40 | 412 | ceph-volume lvm create --filestore --data /dev/sd[X] --journal /dev/sd[Y] |
21394e70 DM |
413 | ---- |
414 | ||
081cb761 | 415 | [[pve_ceph_osd_destroy]] |
b3338e29 AA |
416 | Destroy OSDs |
417 | ~~~~~~~~~~~~ | |
be2d137e AA |
418 | |
419 | To remove an OSD via the GUI first select a {PVE} node in the tree view and go | |
420 | to the **Ceph -> OSD** panel. Select the OSD to destroy. Next click the **OUT** | |
421 | button. Once the OSD status changed from `in` to `out` click the **STOP** | |
422 | button. As soon as the status changed from `up` to `down` select **Destroy** | |
423 | from the `More` drop-down menu. | |
424 | ||
425 | To remove an OSD via the CLI run the following commands. | |
426 | [source,bash] | |
427 | ---- | |
428 | ceph osd out <ID> | |
429 | systemctl stop ceph-osd@<ID>.service | |
430 | ---- | |
431 | NOTE: The first command instructs Ceph not to include the OSD in the data | |
432 | distribution. The second command stops the OSD service. Until this time, no | |
433 | data is lost. | |
434 | ||
435 | The following command destroys the OSD. Specify the '-cleanup' option to | |
436 | additionally destroy the partition table. | |
437 | [source,bash] | |
438 | ---- | |
439 | pveceph osd destroy <ID> | |
440 | ---- | |
441 | WARNING: The above command will destroy data on the disk! | |
442 | ||
443 | ||
07fef357 | 444 | [[pve_ceph_pools]] |
b3338e29 AA |
445 | Ceph Pools |
446 | ---------- | |
1d54c3b4 | 447 | A pool is a logical group for storing objects. It holds **P**lacement |
90682f35 | 448 | **G**roups (`PG`, `pg_num`), a collection of objects. |
1d54c3b4 | 449 | |
b3338e29 AA |
450 | |
451 | Create Pools | |
452 | ~~~~~~~~~~~~ | |
453 | ||
454 | [thumbnail="screenshot/gui-ceph-pools.png"] | |
455 | ||
90682f35 TL |
456 | When no options are given, we set a default of **128 PGs**, a **size of 3 |
457 | replicas** and a **min_size of 2 replicas** for serving objects in a degraded | |
458 | state. | |
1d54c3b4 | 459 | |
5a54ef44 | 460 | NOTE: The default number of PGs works for 2-5 disks. Ceph throws a |
90682f35 | 461 | 'HEALTH_WARNING' if you have too few or too many PGs in your cluster. |
1d54c3b4 AA |
462 | |
463 | It is advised to calculate the PG number depending on your setup, you can find | |
a474ca1f | 464 | the formula and the PG calculator footnote:[PG calculator |
2798d126 | 465 | https://ceph.com/pgcalc/] online. While PGs can be increased later on, they can |
a474ca1f | 466 | never be decreased. |
1d54c3b4 AA |
467 | |
468 | ||
469 | You can create pools through command line or on the GUI on each PVE host under | |
470 | **Ceph -> Pools**. | |
471 | ||
472 | [source,bash] | |
473 | ---- | |
d1fdb121 | 474 | pveceph pool create <name> |
1d54c3b4 AA |
475 | ---- |
476 | ||
620d6725 FE |
477 | If you would like to automatically also get a storage definition for your pool, |
478 | mark the checkbox "Add storages" in the GUI or use the command line option | |
479 | '--add_storages' at pool creation. | |
21394e70 | 480 | |
1d54c3b4 AA |
481 | Further information on Ceph pool handling can be found in the Ceph pool |
482 | operation footnote:[Ceph pool operation | |
2798d126 | 483 | https://docs.ceph.com/docs/{ceph_codename}/rados/operations/pools/] |
1d54c3b4 | 484 | manual. |
21394e70 | 485 | |
166c91fe | 486 | |
b3338e29 AA |
487 | Destroy Pools |
488 | ~~~~~~~~~~~~~ | |
166c91fe AA |
489 | |
490 | To destroy a pool via the GUI select a node in the tree view and go to the | |
491 | **Ceph -> Pools** panel. Select the pool to destroy and click the **Destroy** | |
492 | button. To confirm the destruction of the pool you need to enter the pool name. | |
493 | ||
494 | Run the following command to destroy a pool. Specify the '-remove_storages' to | |
495 | also remove the associated storage. | |
496 | [source,bash] | |
497 | ---- | |
498 | pveceph pool destroy <name> | |
499 | ---- | |
500 | ||
501 | NOTE: Deleting the data of a pool is a background task and can take some time. | |
502 | You will notice that the data usage in the cluster is decreasing. | |
503 | ||
76f6eca4 | 504 | [[pve_ceph_device_classes]] |
9fad507d AA |
505 | Ceph CRUSH & device classes |
506 | --------------------------- | |
507 | The foundation of Ceph is its algorithm, **C**ontrolled **R**eplication | |
508 | **U**nder **S**calable **H**ashing | |
509 | (CRUSH footnote:[CRUSH https://ceph.com/wp-content/uploads/2016/08/weil-crush-sc06.pdf]). | |
510 | ||
511 | CRUSH calculates where to store to and retrieve data from, this has the | |
512 | advantage that no central index service is needed. CRUSH works with a map of | |
513 | OSDs, buckets (device locations) and rulesets (data replication) for pools. | |
514 | ||
515 | NOTE: Further information can be found in the Ceph documentation, under the | |
2798d126 | 516 | section CRUSH map footnote:[CRUSH map https://docs.ceph.com/docs/{ceph_codename}/rados/operations/crush-map/]. |
9fad507d AA |
517 | |
518 | This map can be altered to reflect different replication hierarchies. The object | |
519 | replicas can be separated (eg. failure domains), while maintaining the desired | |
520 | distribution. | |
521 | ||
522 | A common use case is to use different classes of disks for different Ceph pools. | |
523 | For this reason, Ceph introduced the device classes with luminous, to | |
524 | accommodate the need for easy ruleset generation. | |
525 | ||
526 | The device classes can be seen in the 'ceph osd tree' output. These classes | |
527 | represent their own root bucket, which can be seen with the below command. | |
528 | ||
529 | [source, bash] | |
530 | ---- | |
531 | ceph osd crush tree --show-shadow | |
532 | ---- | |
533 | ||
534 | Example output form the above command: | |
535 | ||
536 | [source, bash] | |
537 | ---- | |
538 | ID CLASS WEIGHT TYPE NAME | |
539 | -16 nvme 2.18307 root default~nvme | |
540 | -13 nvme 0.72769 host sumi1~nvme | |
541 | 12 nvme 0.72769 osd.12 | |
542 | -14 nvme 0.72769 host sumi2~nvme | |
543 | 13 nvme 0.72769 osd.13 | |
544 | -15 nvme 0.72769 host sumi3~nvme | |
545 | 14 nvme 0.72769 osd.14 | |
546 | -1 7.70544 root default | |
547 | -3 2.56848 host sumi1 | |
548 | 12 nvme 0.72769 osd.12 | |
549 | -5 2.56848 host sumi2 | |
550 | 13 nvme 0.72769 osd.13 | |
551 | -7 2.56848 host sumi3 | |
552 | 14 nvme 0.72769 osd.14 | |
553 | ---- | |
554 | ||
555 | To let a pool distribute its objects only on a specific device class, you need | |
556 | to create a ruleset with the specific class first. | |
557 | ||
558 | [source, bash] | |
559 | ---- | |
560 | ceph osd crush rule create-replicated <rule-name> <root> <failure-domain> <class> | |
561 | ---- | |
562 | ||
563 | [frame="none",grid="none", align="left", cols="30%,70%"] | |
564 | |=== | |
565 | |<rule-name>|name of the rule, to connect with a pool (seen in GUI & CLI) | |
566 | |<root>|which crush root it should belong to (default ceph root "default") | |
567 | |<failure-domain>|at which failure-domain the objects should be distributed (usually host) | |
568 | |<class>|what type of OSD backing store to use (eg. nvme, ssd, hdd) | |
569 | |=== | |
570 | ||
571 | Once the rule is in the CRUSH map, you can tell a pool to use the ruleset. | |
572 | ||
573 | [source, bash] | |
574 | ---- | |
575 | ceph osd pool set <pool-name> crush_rule <rule-name> | |
576 | ---- | |
577 | ||
578 | TIP: If the pool already contains objects, all of these have to be moved | |
b3338e29 AA |
579 | accordingly. Depending on your setup this may introduce a big performance hit |
580 | on your cluster. As an alternative, you can create a new pool and move disks | |
9fad507d AA |
581 | separately. |
582 | ||
583 | ||
21394e70 DM |
584 | Ceph Client |
585 | ----------- | |
586 | ||
1ff5e4e8 | 587 | [thumbnail="screenshot/gui-ceph-log.png"] |
8997dd6e | 588 | |
21394e70 DM |
589 | You can then configure {pve} to use such pools to store VM or |
590 | Container images. Simply use the GUI too add a new `RBD` storage (see | |
591 | section xref:ceph_rados_block_devices[Ceph RADOS Block Devices (RBD)]). | |
592 | ||
620d6725 | 593 | You also need to copy the keyring to a predefined location for an external Ceph |
1d54c3b4 AA |
594 | cluster. If Ceph is installed on the Proxmox nodes itself, then this will be |
595 | done automatically. | |
21394e70 DM |
596 | |
597 | NOTE: The file name needs to be `<storage_id> + `.keyring` - `<storage_id>` is | |
598 | the expression after 'rbd:' in `/etc/pve/storage.cfg` which is | |
599 | `my-ceph-storage` in the following example: | |
600 | ||
601 | [source,bash] | |
602 | ---- | |
603 | mkdir /etc/pve/priv/ceph | |
604 | cp /etc/ceph/ceph.client.admin.keyring /etc/pve/priv/ceph/my-ceph-storage.keyring | |
605 | ---- | |
0840a663 | 606 | |
58f95dd7 TL |
607 | [[pveceph_fs]] |
608 | CephFS | |
609 | ------ | |
610 | ||
611 | Ceph provides also a filesystem running on top of the same object storage as | |
612 | RADOS block devices do. A **M**eta**d**ata **S**erver (`MDS`) is used to map | |
613 | the RADOS backed objects to files and directories, allowing to provide a | |
614 | POSIX-compliant replicated filesystem. This allows one to have a clustered | |
615 | highly available shared filesystem in an easy way if ceph is already used. Its | |
616 | Metadata Servers guarantee that files get balanced out over the whole Ceph | |
617 | cluster, this way even high load will not overload a single host, which can be | |
d180eb39 | 618 | an issue with traditional shared filesystem approaches, like `NFS`, for |
58f95dd7 TL |
619 | example. |
620 | ||
1e834cb2 TL |
621 | [thumbnail="screenshot/gui-node-ceph-cephfs-panel.png"] |
622 | ||
2394c306 | 623 | {pve} supports both, using an existing xref:storage_cephfs[CephFS as storage] |
58f95dd7 TL |
624 | to save backups, ISO files or container templates and creating a |
625 | hyper-converged CephFS itself. | |
626 | ||
627 | ||
628 | [[pveceph_fs_mds]] | |
629 | Metadata Server (MDS) | |
630 | ~~~~~~~~~~~~~~~~~~~~~ | |
631 | ||
632 | CephFS needs at least one Metadata Server to be configured and running to be | |
633 | able to work. One can simply create one through the {pve} web GUI's `Node -> | |
634 | CephFS` panel or on the command line with: | |
635 | ||
636 | ---- | |
637 | pveceph mds create | |
638 | ---- | |
639 | ||
640 | Multiple metadata servers can be created in a cluster. But with the default | |
641 | settings only one can be active at any time. If an MDS, or its node, becomes | |
642 | unresponsive (or crashes), another `standby` MDS will get promoted to `active`. | |
643 | One can speed up the hand-over between the active and a standby MDS up by using | |
644 | the 'hotstandby' parameter option on create, or if you have already created it | |
645 | you may set/add: | |
646 | ||
647 | ---- | |
648 | mds standby replay = true | |
649 | ---- | |
650 | ||
651 | in the ceph.conf respective MDS section. With this enabled, this specific MDS | |
652 | will always poll the active one, so that it can take over faster as it is in a | |
3580eb13 | 653 | `warm` state. But naturally, the active polling will cause some additional |
58f95dd7 TL |
654 | performance impact on your system and active `MDS`. |
655 | ||
1e834cb2 | 656 | .Multiple Active MDS |
58f95dd7 TL |
657 | |
658 | Since Luminous (12.2.x) you can also have multiple active metadata servers | |
659 | running, but this is normally only useful for a high count on parallel clients, | |
660 | as else the `MDS` seldom is the bottleneck. If you want to set this up please | |
661 | refer to the ceph documentation. footnote:[Configuring multiple active MDS | |
2798d126 | 662 | daemons https://docs.ceph.com/docs/{ceph_codename}/cephfs/multimds/] |
58f95dd7 TL |
663 | |
664 | [[pveceph_fs_create]] | |
8a38333f AA |
665 | Create CephFS |
666 | ~~~~~~~~~~~~~ | |
58f95dd7 TL |
667 | |
668 | With {pve}'s CephFS integration into you can create a CephFS easily over the | |
669 | Web GUI, the CLI or an external API interface. Some prerequisites are required | |
670 | for this to work: | |
671 | ||
672 | .Prerequisites for a successful CephFS setup: | |
673 | - xref:pve_ceph_install[Install Ceph packages], if this was already done some | |
674 | time ago you might want to rerun it on an up to date system to ensure that | |
675 | also all CephFS related packages get installed. | |
676 | - xref:pve_ceph_monitors[Setup Monitors] | |
677 | - xref:pve_ceph_monitors[Setup your OSDs] | |
678 | - xref:pveceph_fs_mds[Setup at least one MDS] | |
679 | ||
680 | After this got all checked and done you can simply create a CephFS through | |
681 | either the Web GUI's `Node -> CephFS` panel or the command line tool `pveceph`, | |
682 | for example with: | |
683 | ||
684 | ---- | |
685 | pveceph fs create --pg_num 128 --add-storage | |
686 | ---- | |
687 | ||
688 | This creates a CephFS named `'cephfs'' using a pool for its data named | |
689 | `'cephfs_data'' with `128` placement groups and a pool for its metadata named | |
690 | `'cephfs_metadata'' with one quarter of the data pools placement groups (`32`). | |
691 | Check the xref:pve_ceph_pools[{pve} managed Ceph pool chapter] or visit the | |
692 | Ceph documentation for more information regarding a fitting placement group | |
693 | number (`pg_num`) for your setup footnote:[Ceph Placement Groups | |
2798d126 | 694 | https://docs.ceph.com/docs/{ceph_codename}/rados/operations/placement-groups/]. |
58f95dd7 TL |
695 | Additionally, the `'--add-storage'' parameter will add the CephFS to the {pve} |
696 | storage configuration after it was created successfully. | |
697 | ||
698 | Destroy CephFS | |
699 | ~~~~~~~~~~~~~~ | |
700 | ||
fa9b4ee1 | 701 | WARNING: Destroying a CephFS will render all its data unusable, this cannot be |
58f95dd7 TL |
702 | undone! |
703 | ||
704 | If you really want to destroy an existing CephFS you first need to stop, or | |
620d6725 | 705 | destroy, all metadata servers (`M̀DS`). You can destroy them either over the Web |
58f95dd7 TL |
706 | GUI or the command line interface, with: |
707 | ||
708 | ---- | |
709 | pveceph mds destroy NAME | |
710 | ---- | |
711 | on each {pve} node hosting a MDS daemon. | |
712 | ||
713 | Then, you can remove (destroy) CephFS by issuing a: | |
714 | ||
715 | ---- | |
de2f8225 | 716 | ceph fs rm NAME --yes-i-really-mean-it |
58f95dd7 TL |
717 | ---- |
718 | on a single node hosting Ceph. After this you may want to remove the created | |
719 | data and metadata pools, this can be done either over the Web GUI or the CLI | |
720 | with: | |
721 | ||
722 | ---- | |
723 | pveceph pool destroy NAME | |
724 | ---- | |
0840a663 | 725 | |
6ff32926 | 726 | |
081cb761 AA |
727 | Ceph maintenance |
728 | ---------------- | |
af6f59f4 | 729 | |
081cb761 AA |
730 | Replace OSDs |
731 | ~~~~~~~~~~~~ | |
af6f59f4 | 732 | |
081cb761 AA |
733 | One of the common maintenance tasks in Ceph is to replace a disk of an OSD. If |
734 | a disk is already in a failed state, then you can go ahead and run through the | |
735 | steps in xref:pve_ceph_osd_destroy[Destroy OSDs]. Ceph will recreate those | |
af6f59f4 TL |
736 | copies on the remaining OSDs if possible. This rebalancing will start as soon |
737 | as an OSD failure is detected or an OSD was actively stopped. | |
738 | ||
739 | NOTE: With the default size/min_size (3/2) of a pool, recovery only starts when | |
740 | `size + 1` nodes are available. The reason for this is that the Ceph object | |
741 | balancer xref:pve_ceph_device_classes[CRUSH] defaults to a full node as | |
742 | `failure domain'. | |
081cb761 AA |
743 | |
744 | To replace a still functioning disk, on the GUI go through the steps in | |
745 | xref:pve_ceph_osd_destroy[Destroy OSDs]. The only addition is to wait until | |
746 | the cluster shows 'HEALTH_OK' before stopping the OSD to destroy it. | |
747 | ||
748 | On the command line use the following commands. | |
749 | ---- | |
750 | ceph osd out osd.<id> | |
751 | ---- | |
752 | ||
753 | You can check with the command below if the OSD can be safely removed. | |
754 | ---- | |
755 | ceph osd safe-to-destroy osd.<id> | |
756 | ---- | |
757 | ||
758 | Once the above check tells you that it is save to remove the OSD, you can | |
759 | continue with following commands. | |
760 | ---- | |
761 | systemctl stop ceph-osd@<id>.service | |
762 | pveceph osd destroy <id> | |
763 | ---- | |
764 | ||
765 | Replace the old disk with the new one and use the same procedure as described | |
766 | in xref:pve_ceph_osd_create[Create OSDs]. | |
767 | ||
835f322d TL |
768 | Trim/Discard |
769 | ~~~~~~~~~~~~ | |
081cb761 AA |
770 | It is a good measure to run 'fstrim' (discard) regularly on VMs or containers. |
771 | This releases data blocks that the filesystem isn’t using anymore. It reduces | |
c78cd2b6 AA |
772 | data usage and resource load. Most modern operating systems issue such discard |
773 | commands to their disks regularly. You only need to ensure that the Virtual | |
774 | Machines enable the xref:qm_hard_disk_discard[disk discard option]. | |
081cb761 | 775 | |
c998bdf2 | 776 | [[pveceph_scrub]] |
081cb761 AA |
777 | Scrub & Deep Scrub |
778 | ~~~~~~~~~~~~~~~~~~ | |
779 | Ceph ensures data integrity by 'scrubbing' placement groups. Ceph checks every | |
780 | object in a PG for its health. There are two forms of Scrubbing, daily | |
b16f8c5f TL |
781 | cheap metadata checks and weekly deep data checks. The weekly deep scrub reads |
782 | the objects and uses checksums to ensure data integrity. If a running scrub | |
783 | interferes with business (performance) needs, you can adjust the time when | |
784 | scrubs footnote:[Ceph scrubbing https://docs.ceph.com/docs/{ceph_codename}/rados/configuration/osd-config-ref/#scrubbing] | |
081cb761 AA |
785 | are executed. |
786 | ||
787 | ||
10df14fb TL |
788 | Ceph monitoring and troubleshooting |
789 | ----------------------------------- | |
790 | A good start is to continuosly monitor the ceph health from the start of | |
791 | initial deployment. Either through the ceph tools itself, but also by accessing | |
792 | the status through the {pve} link:api-viewer/index.html[API]. | |
6ff32926 | 793 | |
10df14fb TL |
794 | The following ceph commands below can be used to see if the cluster is healthy |
795 | ('HEALTH_OK'), if there are warnings ('HEALTH_WARN'), or even errors | |
796 | ('HEALTH_ERR'). If the cluster is in an unhealthy state the status commands | |
620d6725 | 797 | below will also give you an overview of the current events and actions to take. |
6ff32926 AA |
798 | |
799 | ---- | |
10df14fb TL |
800 | # single time output |
801 | pve# ceph -s | |
802 | # continuously output status changes (press CTRL+C to stop) | |
803 | pve# ceph -w | |
6ff32926 AA |
804 | ---- |
805 | ||
806 | To get a more detailed view, every ceph service has a log file under | |
807 | `/var/log/ceph/` and if there is not enough detail, the log level can be | |
2798d126 | 808 | adjusted footnote:[Ceph log and debugging https://docs.ceph.com/docs/{ceph_codename}/rados/troubleshooting/log-and-debug/]. |
6ff32926 AA |
809 | |
810 | You can find more information about troubleshooting | |
2798d126 | 811 | footnote:[Ceph troubleshooting https://docs.ceph.com/docs/{ceph_codename}/rados/troubleshooting/] |
620d6725 | 812 | a Ceph cluster on the official website. |
6ff32926 AA |
813 | |
814 | ||
0840a663 DM |
815 | ifdef::manvolnum[] |
816 | include::pve-copyright.adoc[] | |
817 | endif::manvolnum[] |