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    Testing ZFS with XCP-ng

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    • borzelB Offline
      borzel XCP-ng Center Team
      last edited by borzel

      Good ressource with a lot of information, how to really use ZFS, build storages, tuning, etc.: https://www.zfsbuild.com 📰

      B 1 Reply Last reply Reply Quote 0
      • B Offline
        buzzzo @borzel
        last edited by

        Zfs is a local sr and imho does not add too much advantages vs classic ext sr

        The real value of zfs is to use built in replication to remote zfs system.
        Proxmox has built a very interesting solutions around it: async replication of vm on a another node.

        I know xoa already offer a similar solution but is snapshot based and everyone knows the performance and size problem with this approach.

        borzelB olivierlambertO 2 Replies Last reply Reply Quote 0
        • borzelB Offline
          borzel XCP-ng Center Team @buzzzo
          last edited by borzel

          @buzzzo said in Testing ZFS with XCP-ng:

          Zfs is a local sr and imho does not add too much advantages vs classic ext sr

          meeeep 🙂

          • ZFS uses (in standard configuration) half the RAM as read cache
          • with sync=disabled your writes are faster (but synced to discs every 5 seconds; in one sequential batch - efficient use of slow spinning drives!)
          • it has checksums from fs-layer down to the device
          • it's awesome 😉

          know xoa already offer a similar solution but is snapshot based and everyone knows the performance and size problem with this approach.

          If we all had 48 hours a day and more people in the team, we could fully integrate ZFS into XCP-ng (with all bells and whistles). But for now we are happy to have the first step done - loose integrate ZFS to start using it and testing stability of the dom0 with ZFS in it.

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          • olivierlambertO Offline
            olivierlambert Vates 🪐 Co-Founder CEO @buzzzo
            last edited by olivierlambert

            @buzzzo Double meeeep 😆

            On file level SR (ext, NFS, local ZFS, XOSAN), there is no space issue doing snapshots. Also, perfs are good even with snapshots if you don't have an asthmatic SR.

            B 1 Reply Last reply Reply Quote 0
            • B Offline
              buzzzo @olivierlambert
              last edited by

              @olivierlambert meeep!!! ☺

              1 Reply Last reply Reply Quote 0
              • olivierlambertO Offline
                olivierlambert Vates 🪐 Co-Founder CEO
                last edited by

                Meep meep!

                1 Reply Last reply Reply Quote 1
                • borzelB Offline
                  borzel XCP-ng Center Team
                  last edited by borzel

                  I tested latest and greatest XO (5.24.1 from sources) with latest XCP-ng 7.5 (incl. xcp-ng-extra repo/ZFS). Backups do not work 😞

                  If the VDI is on a ext-SR, all is fine, backup working.
                  If the VDI is on a File-SR (ZFS based), the backup says "VDI_ERROR" or "VDI Chain to long". I will provide logfiles tomorrow if needed.

                  Setup of my File-SR:
                  xe sr-create host-uuid=<xxx> name-label=zfssr type=file other-config:o_direct=false device-config:location=/zfspool/zfssr

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                  • olivierlambertO Offline
                    olivierlambert Vates 🪐 Co-Founder CEO
                    last edited by

                    VDI chain too long doesn't seems related. It means you have a VDI chain that's around 30 files.

                    Can you provide the exact/detailed error log?

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                    • borzelB Offline
                      borzel XCP-ng Center Team
                      last edited by borzel

                      0_1534286419566_560b7fad-965d-42bc-8f40-2eed276163b8-grafik.png

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                      • borzelB Offline
                        borzel XCP-ng Center Team
                        last edited by borzel

                        I searched in xensource.log, SMlog and syslog, no related entries found 😞

                        How can I increase the loglevel of XO?

                        Here's the log output if I start this job again:

                        Aug 15 01:10:35 ubuntu xo-server[616]: 2018-08-14T23:10:35.241Z xo:xapi Snapshotting VM pmg as [XO Backup test] pmg
                        Aug 15 01:10:36 ubuntu xo-server[616]: 2018-08-14T23:10:36.948Z xo:xapi exporting VDI pmg 0
                        Aug 15 01:10:41 ubuntu xo-server[616]: 2018-08-14T23:10:41.289Z xo:xapi Deleting VM [XO Backup test] pmg
                        Aug 15 01:10:41 ubuntu xo-server[616]: 2018-08-14T23:10:41.585Z xo:xapi Deleting VDI pmg 0
                        

                        It's nearly nothing...

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                        • nraynaudN Offline
                          nraynaud XCP-ng Team
                          last edited by

                          @borzel > The error is often in the Settings->Logs panel in XO in this case

                          borzelB 1 Reply Last reply Reply Quote 0
                          • borzelB Offline
                            borzel XCP-ng Center Team @nraynaud
                            last edited by

                            @nraynaud no, it's as empty as it could be 😞

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                            • borzelB Offline
                              borzel XCP-ng Center Team
                              last edited by

                              I found something in /var/log/xensource.log (used tail -f /var/log/xensource.log | grep -i 'error')

                              Aug 14 23:19:10 hw xapi: [error|hw|63005 INET :::80|[XO] VDI Export R:3001f7e5aa17|vhd_tool_wrapper] vhd-tool failed, returning VDI_IO_ERROR
                              Aug 14 23:19:10 hw xapi: [error|hw|63005 INET :::80|[XO] VDI Export R:3001f7e5aa17|vhd_tool_wrapper] vhd-tool output: vhd-tool: internal error, uncaught exception:#012          Unix.Unix_error(Unix.EINVAL, "open", "/var/run/sr-mount/9fc67ea3-c9b3-5e62-ecc3-7d1debf81744/6781ab7b-c475-4d72-a7d0-b2aeca2e81e3.vhd")#012          Raised at file "src/core/lwt.ml", line 3008, characters 20-29#012          Called from file "src/unix/lwt_main.ml", line 42, characters 8-18#012          Called from file "src/impl.ml", line 811, characters 4-23#012          Called from file "src/cmdliner_term.ml", line 27, characters 19-24#012          Called from file "src/cmdliner.ml", line 27, characters 27-34#012          Called from file "src/cmdliner.ml", line 106, characters 32-39
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] [XO] VDI Export R:3001f7e5aa17 failed with exception Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] Raised Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 1/13 xapi @ hw Raised at file ocaml/xapi/vhd_tool_wrapper.ml, line 59
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 2/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 3/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 4/13 xapi @ hw Called from file ocaml/xapi/export_raw_vdi.ml, line 47
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 5/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 6/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 7/13 xapi @ hw Called from file ocaml/xapi/export_raw_vdi.ml, line 54
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 8/13 xapi @ hw Called from file ocaml/xapi/export_raw_vdi.ml, line 65
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 9/13 xapi @ hw Called from file ocaml/xapi/server_helpers.ml, line 73
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 10/13 xapi @ hw Called from file ocaml/xapi/server_helpers.ml, line 91
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 11/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 12/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace] 13/13 xapi @ hw Called from file lib/backtrace.ml, line 177
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:315adbf2ec6c|backtrace]
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] VDI.export_raw_vdi D:315adbf2ec6c failed with exception Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] Raised Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 1/13 xapi @ hw Raised at file lib/debug.ml, line 187
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 2/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 3/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 4/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 5/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 6/13 xapi @ hw Called from file ocaml/xapi/xapi_http.ml, line 185
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 7/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 8/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 9/13 xapi @ hw Called from file ocaml/xapi/server_helpers.ml, line 73
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 10/13 xapi @ hw Called from file ocaml/xapi/server_helpers.ml, line 91
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 11/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 22
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 12/13 xapi @ hw Called from file lib/xapi-stdext-pervasives/pervasiveext.ml, line 26
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace] 13/13 xapi @ hw Called from file lib/backtrace.ml, line 177
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80|VDI.export_raw_vdi D:fc8d0f58f1be|backtrace]
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80||backtrace] VDI.export_raw_vdi D:fc8d0f58f1be failed with exception Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80||backtrace] Raised Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80||backtrace] 1/1 xapi @ hw Raised at file (Thread 63005 has no backtrace table. Was with_backtraces called?, line 0
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80||backtrace]
                              Aug 14 23:19:11 hw xapi: [error|hw|63005 INET :::80||xapi] Unhandled Api_errors.Server_error(VDI_IO_ERROR, [ Device I/O errors ])
                              
                              nraynaudN 1 Reply Last reply Reply Quote 0
                              • olivierlambertO Offline
                                olivierlambert Vates 🪐 Co-Founder CEO
                                last edited by

                                I'll try to run some tests on my side.

                                1 Reply Last reply Reply Quote 0
                                • stormiS Offline
                                  stormi Vates 🪐 XCP-ng Team @borzel
                                  last edited by

                                  @borzel I'm not very familiar with github wikis, but I think you can do pull requests against the wiki.

                                  borzelB 1 Reply Last reply Reply Quote 0
                                  • borzelB Offline
                                    borzel XCP-ng Center Team @stormi
                                    last edited by

                                    @stormi wiki issue is allready solved 😉

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                                    • nraynaudN Offline
                                      nraynaud XCP-ng Team @borzel
                                      last edited by

                                      @borzel good catch, it's another O_DIRECT issue.

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                                      • nraynaudN Offline
                                        nraynaud XCP-ng Team
                                        last edited by

                                        @borzel I am struggling to match the error lines in your log with a source code, can you tell me what version of vhd-tool you have installed please ? (yum info vhd-tool)

                                        borzelB 1 Reply Last reply Reply Quote 0
                                        • borzelB Offline
                                          borzel XCP-ng Center Team @nraynaud
                                          last edited by borzel

                                          @nraynaud

                                          # yum info vhd-tool
                                          Loaded plugins: fastestmirror
                                          Loading mirror speeds from cached hostfile
                                          Installed Packages
                                          Name        : vhd-tool
                                          Arch        : x86_64
                                          Version     : 0.20.0
                                          Release     : 4.2.xcp.el7.centos.extras
                                          Size        : 40 M
                                          Repo        : installed
                                          From repo   : xcp-ng-extras
                                          Summary     : Command-line tools for manipulating and
                                                      : streaming .vhd format files
                                          URL         : https://github.com/xapi-project/vhd-tool
                                          License     : LGPL+linking exception
                                          Description : Simple command-line tools for manipulating an
                                                      : streaming .vhd format file.
                                          
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                                          • nraynaudN Offline
                                            nraynaud XCP-ng Team
                                            last edited by

                                            Thanks,
                                            I have found a suspected O_DIRECT here, the solution won't come quickly.

                                            borzelB 1 Reply Last reply Reply Quote 0
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