diff --git a/src/backend/middlewares/admin/AdminMWs.ts b/src/backend/middlewares/admin/AdminMWs.ts
index d229534f..c9c40b04 100644
--- a/src/backend/middlewares/admin/AdminMWs.ts
+++ b/src/backend/middlewares/admin/AdminMWs.ts
@@ -51,21 +51,21 @@ export class AdminMWs {
   }
 
 
-  public static startJob(soloRun: boolean) {
-    return async (req: Request, res: Response, next: NextFunction) => {
-      try {
-        const id = req.params.id;
-        const JobConfig: any = req.body.config;
-        await ObjectManagers.getInstance().JobManager.run(id, JobConfig, soloRun);
-        req.resultPipe = 'ok';
-        return next();
-      } catch (err) {
-        if (err instanceof Error) {
-          return next(new ErrorDTO(ErrorCodes.JOB_ERROR, 'Job error: ' + err.toString(), err));
-        }
-        return next(new ErrorDTO(ErrorCodes.JOB_ERROR, 'Job error: ' + JSON.stringify(err, null, '  '), err));
+  public static async startJob(req: Request, res: Response, next: NextFunction) {
+    try {
+      const id = req.params.id;
+      const JobConfig: any = req.body.config;
+      const soloRun: boolean = req.body.soloRun;
+      const allowParallelRun: boolean = req.body.allowParallelRun;
+      await ObjectManagers.getInstance().JobManager.run(id, JobConfig, soloRun, allowParallelRun);
+      req.resultPipe = 'ok';
+      return next();
+    } catch (err) {
+      if (err instanceof Error) {
+        return next(new ErrorDTO(ErrorCodes.JOB_ERROR, 'Job error: ' + err.toString(), err));
       }
-    };
+      return next(new ErrorDTO(ErrorCodes.JOB_ERROR, 'Job error: ' + JSON.stringify(err, null, '  '), err));
+    }
   }
 
   public static stopJob(req: Request, res: Response, next: NextFunction) {
diff --git a/src/backend/model/database/interfaces/IJobManager.ts b/src/backend/model/database/interfaces/IJobManager.ts
index ac882dc9..867d6f32 100644
--- a/src/backend/model/database/interfaces/IJobManager.ts
+++ b/src/backend/model/database/interfaces/IJobManager.ts
@@ -4,7 +4,7 @@ import {JobDTO} from '../../../../common/entities/job/JobDTO';
 export interface IJobManager {
 
 
-  run(jobId: string, config: any, soloRun: boolean): Promise<void>;
+  run(jobId: string, config: any, soloRun: boolean, allowParallelRun: boolean): Promise<void>;
 
   stop(jobId: string): void;
 
diff --git a/src/backend/model/jobs/JobManager.ts b/src/backend/model/jobs/JobManager.ts
index 8c885cfc..94655ea8 100644
--- a/src/backend/model/jobs/JobManager.ts
+++ b/src/backend/model/jobs/JobManager.ts
@@ -22,15 +22,28 @@ export class JobManager implements IJobManager, IJobListener {
     this.runSchedules();
   }
 
+  protected get JobRunning(): boolean {
+    return JobRepository.Instance.getAvailableJobs().findIndex(j => j.InProgress === true) !== -1;
+  }
+
+  protected get JobNoParallelRunning(): boolean {
+    return JobRepository.Instance.getAvailableJobs()
+      .findIndex(j => j.InProgress === true && j.allowParallelRun) !== -1;
+  }
+
   getProgresses(): { [id: string]: JobProgressDTO } {
     return this.progressManager.Progresses;
   }
 
-  async run<T>(jobName: string, config: T, soloRun: boolean): Promise<void> {
+  async run<T>(jobName: string, config: T, soloRun: boolean, allowParallelRun: boolean): Promise<void> {
+    if ((allowParallelRun === false && this.JobRunning === true) || this.JobNoParallelRunning === true) {
+      throw new Error('Can\'t start this job while an other is running');
+    }
+
     const t = this.findJob(jobName);
     if (t) {
       t.JobListener = this;
-      await t.start(config, soloRun);
+      await t.start(config, soloRun, allowParallelRun);
     } else {
       Logger.warn(LOG_TAG, 'cannot find job to start:' + jobName);
     }
@@ -49,7 +62,6 @@ export class JobManager implements IJobManager, IJobListener {
     this.progressManager.onJobProgressUpdate(progress.toDTO());
   };
 
-
   onJobFinished = async (job: IJob<any>, state: JobProgressStates, soloRun: boolean): Promise<void> => {
     // if it was not finished peacefully or was a soloRun, do not start the next one
     if (state !== JobProgressStates.finished || soloRun === true) {
@@ -61,7 +73,7 @@ export class JobManager implements IJobManager, IJobListener {
         (<AfterJobTrigger>s.trigger).afterScheduleName === sch.name);
       for (let i = 0; i < children.length; ++i) {
         try {
-          await this.run(children[i].jobName, children[i].config, false);
+          await this.run(children[i].jobName, children[i].config, false, children[i].allowParallelRun);
         } catch (e) {
           NotificationManager.warning('Job running error:' + children[i].name, e.toString());
         }
@@ -96,7 +108,7 @@ export class JobManager implements IJobManager, IJobListener {
 
       const timer: NodeJS.Timeout = setTimeout(async () => {
         this.timers = this.timers.filter(t => t.timer !== timer);
-        await this.run(schedule.jobName, schedule.config, false);
+        await this.run(schedule.jobName, schedule.config, false, schedule.allowParallelRun);
         this.runSchedule(schedule);
       }, nextDate.getTime() - Date.now());
       this.timers.push({schedule: schedule, timer: timer});
diff --git a/src/backend/model/jobs/JobProgressManager.ts b/src/backend/model/jobs/JobProgressManager.ts
index 7c205551..5f153baa 100644
--- a/src/backend/model/jobs/JobProgressManager.ts
+++ b/src/backend/model/jobs/JobProgressManager.ts
@@ -33,6 +33,7 @@ export class JobProgressManager {
   }
 
 
+
   onJobProgressUpdate(progress: JobProgressDTO) {
     this.db.progresses[progress.HashName] = {progress: progress, timestamp: Date.now()};
     this.delayedSave();
diff --git a/src/backend/model/jobs/jobs/IJob.ts b/src/backend/model/jobs/jobs/IJob.ts
index 6ca30d7c..acd84d5a 100644
--- a/src/backend/model/jobs/jobs/IJob.ts
+++ b/src/backend/model/jobs/jobs/IJob.ts
@@ -7,8 +7,10 @@ export interface IJob<T> extends JobDTO {
   Supported: boolean;
   Progress: JobProgress;
   JobListener: IJobListener;
+  InProgress: boolean;
+  allowParallelRun: boolean;
 
-  start(config: T, soloRun?: boolean): Promise<void>;
+  start(config: T, soloRun: boolean, allowParallelRun: boolean): Promise<void>;
 
   cancel(): void;
 
diff --git a/src/backend/model/jobs/jobs/Job.ts b/src/backend/model/jobs/jobs/Job.ts
index 30a7b3ca..0ad52a36 100644
--- a/src/backend/model/jobs/jobs/Job.ts
+++ b/src/backend/model/jobs/jobs/Job.ts
@@ -11,6 +11,7 @@ declare const global: any;
 const LOG_TAG = '[JOB]';
 
 export abstract class Job<T = void> implements IJob<T> {
+  public allowParallelRun: boolean = null;
   protected progress: JobProgress = null;
   protected config: T;
   protected prResolve: () => void;
@@ -33,15 +34,16 @@ export abstract class Job<T = void> implements IJob<T> {
     return this.progress;
   }
 
-  protected get InProgress(): boolean {
+  public get InProgress(): boolean {
     return this.Progress !== null && (this.Progress.State === JobProgressStates.running ||
       this.Progress.State === JobProgressStates.cancelling);
   }
 
-  public start(config: T, soloRun = false): Promise<void> {
+  public start(config: T, soloRun = false, allowParallelRun = false): Promise<void> {
     if (this.InProgress === false && this.Supported === true) {
       Logger.info(LOG_TAG, 'Running job ' + (soloRun === true ? 'solo' : '') + ': ' + this.Name);
       this.soloRun = soloRun;
+      this.allowParallelRun = allowParallelRun;
       this.config = config;
       this.progress = new JobProgress(this.Name, JobDTO.getHashName(this.Name, this.config));
       this.progress.OnChange = this.jobListener.onProgressUpdate;
diff --git a/src/backend/model/jobs/jobs/ThumbnailGenerationJob.ts b/src/backend/model/jobs/jobs/ThumbnailGenerationJob.ts
index c347cd6d..9c71d461 100644
--- a/src/backend/model/jobs/jobs/ThumbnailGenerationJob.ts
+++ b/src/backend/model/jobs/jobs/ThumbnailGenerationJob.ts
@@ -29,14 +29,14 @@ export class ThumbnailGenerationJob extends FileJob<{ sizes: number[], indexedOn
     return true;
   }
 
-  start(config: { sizes: number[], indexedOnly: boolean }, soloRun = false): Promise<void> {
+  start(config: { sizes: number[], indexedOnly: boolean }, soloRun = false, allowParallelRun = false): Promise<void> {
     for (let i = 0; i < config.sizes.length; ++i) {
       if (Config.Client.Media.Thumbnail.thumbnailSizes.indexOf(config.sizes[i]) === -1) {
         throw new Error('unknown thumbnails size: ' + config.sizes[i] + '. Add it to the possible thumbnail sizes.');
       }
     }
 
-    return super.start(config, soloRun);
+    return super.start(config, soloRun, allowParallelRun);
   }
 
   protected async filterMediaFiles(files: FileDTO[]): Promise<FileDTO[]> {
diff --git a/src/backend/routes/admin/AdminRouter.ts b/src/backend/routes/admin/AdminRouter.ts
index 9bb77fe5..5bd4d1c9 100644
--- a/src/backend/routes/admin/AdminRouter.ts
+++ b/src/backend/routes/admin/AdminRouter.ts
@@ -46,13 +46,7 @@ export class AdminRouter {
     app.post('/api/admin/jobs/scheduled/:id/start',
       AuthenticationMWs.authenticate,
       AuthenticationMWs.authorise(UserRoles.Admin),
-      AdminMWs.startJob(false),
-      RenderingMWs.renderResult
-    );
-    app.post('/api/admin/jobs/scheduled/:id/soloStart',
-      AuthenticationMWs.authenticate,
-      AuthenticationMWs.authorise(UserRoles.Admin),
-      AdminMWs.startJob(true),
+      AdminMWs.startJob,
       RenderingMWs.renderResult
     );
     app.post('/api/admin/jobs/scheduled/:id/stop',
diff --git a/src/common/config/private/PrivateConfigDefaultsClass.ts b/src/common/config/private/PrivateConfigDefaultsClass.ts
index 80ab9dc3..94032041 100644
--- a/src/common/config/private/PrivateConfigDefaultsClass.ts
+++ b/src/common/config/private/PrivateConfigDefaultsClass.ts
@@ -75,6 +75,7 @@ export class PrivateConfigDefaultsClass extends PublicConfigClass implements IPr
         {
           name: DefaultsJobs[DefaultsJobs.Indexing],
           jobName: DefaultsJobs[DefaultsJobs.Indexing],
+          allowParallelRun: false,
           config: {},
           trigger: {type: JobTriggerType.never}
         },
@@ -82,24 +83,27 @@ export class PrivateConfigDefaultsClass extends PublicConfigClass implements IPr
           name: DefaultsJobs[DefaultsJobs['Thumbnail Generation']],
           jobName: DefaultsJobs[DefaultsJobs['Thumbnail Generation']],
           config: {sizes: [240]},
+          allowParallelRun: false,
           trigger: {
             type: JobTriggerType.after,
             afterScheduleName: DefaultsJobs[DefaultsJobs.Indexing]
           }
         },
-      /*  {
-          name: DefaultsJobs[DefaultsJobs['Photo Converting']],
-          jobName: DefaultsJobs[DefaultsJobs['Photo Converting']],
-          config: {},
-          trigger: {
-            type: JobTriggerType.after,
-            afterScheduleName: DefaultsJobs[DefaultsJobs['Thumbnail Generation']]
-          }
-        },*/
+        /*  {
+            name: DefaultsJobs[DefaultsJobs['Photo Converting']],
+            jobName: DefaultsJobs[DefaultsJobs['Photo Converting']],
+            config: {},
+            parallelRunEnabled:false,
+            trigger: {
+              type: JobTriggerType.after,
+              afterScheduleName: DefaultsJobs[DefaultsJobs['Thumbnail Generation']]
+            }
+          },*/
         {
           name: DefaultsJobs[DefaultsJobs['Video Converting']],
           jobName: DefaultsJobs[DefaultsJobs['Video Converting']],
           config: {},
+          allowParallelRun: false,
           trigger: {
             type: JobTriggerType.after,
             afterScheduleName: DefaultsJobs[DefaultsJobs['Thumbnail Generation']]
@@ -109,6 +113,7 @@ export class PrivateConfigDefaultsClass extends PublicConfigClass implements IPr
           name: DefaultsJobs[DefaultsJobs['Temp Folder Cleaning']],
           jobName: DefaultsJobs[DefaultsJobs['Temp Folder Cleaning']],
           config: {},
+          allowParallelRun: false,
           trigger: {
             type: JobTriggerType.after,
             afterScheduleName: DefaultsJobs[DefaultsJobs['Video Converting']]
diff --git a/src/common/entities/job/JobScheduleDTO.ts b/src/common/entities/job/JobScheduleDTO.ts
index a7958522..8a366694 100644
--- a/src/common/entities/job/JobScheduleDTO.ts
+++ b/src/common/entities/job/JobScheduleDTO.ts
@@ -30,6 +30,7 @@ export interface JobScheduleDTO {
   name: string;
   jobName: string;
   config: any;
+  allowParallelRun: boolean;
   trigger: NeverJobTrigger | ScheduledJobTrigger | PeriodicJobTrigger | AfterJobTrigger;
 }
 
diff --git a/src/frontend/app/ui/settings/indexing/indexing.settings.component.html b/src/frontend/app/ui/settings/indexing/indexing.settings.component.html
index d14402e8..5ad471af 100644
--- a/src/frontend/app/ui/settings/indexing/indexing.settings.component.html
+++ b/src/frontend/app/ui/settings/indexing/indexing.settings.component.html
@@ -114,6 +114,7 @@
       <app-settings-job-button #indexingButton
                                [soloRun]="true"
                                (error)="error=$event"
+                               [allowParallelRun]="false"
                                [jobName]="indexingJobName"></app-settings-job-button>
 
 
@@ -121,6 +122,7 @@
                                danger="true"
                                [soloRun]="true"
                                (error)="error=$event"
+                               [allowParallelRun]="false"
                                [disabled]="indexingButton.Running"
                                [jobName]="resetJobName"></app-settings-job-button>
 
diff --git a/src/frontend/app/ui/settings/jobs/button/job-button.settings.component.ts b/src/frontend/app/ui/settings/jobs/button/job-button.settings.component.ts
index 23bdf312..0cd141a8 100644
--- a/src/frontend/app/ui/settings/jobs/button/job-button.settings.component.ts
+++ b/src/frontend/app/ui/settings/jobs/button/job-button.settings.component.ts
@@ -18,6 +18,7 @@ export class JobButtonComponent {
   @Input() shortName = false;
   @Input() disabled = false;
   @Input() soloRun = false;
+  @Input() allowParallelRun = false;
   @Input() danger = false;
   JobProgressStates = JobProgressStates;
   @Output() error = new EventEmitter<string>();
@@ -40,7 +41,7 @@ export class JobButtonComponent {
   public async start() {
     this.error.emit('');
     try {
-      await this.jobsService.start(this.jobName, this.config, this.soloRun);
+      await this.jobsService.start(this.jobName, this.config, this.soloRun, this.allowParallelRun);
       this.notification.success(this.i18n('Job started') + ': ' + this.backendTextService.getJobName(this.jobName));
       return true;
     } catch (err) {
@@ -57,7 +58,7 @@ export class JobButtonComponent {
     this.error.emit('');
     try {
       await this.jobsService.stop(this.jobName);
-      this.notification.info(this.i18n('Job stopped') + ': ' + this.backendTextService.getJobName(this.jobName));
+      this.notification.info(this.i18n('Stopping job') + ': ' + this.backendTextService.getJobName(this.jobName));
       return true;
     } catch (err) {
       console.log(err);
diff --git a/src/frontend/app/ui/settings/jobs/jobs.settings.component.html b/src/frontend/app/ui/settings/jobs/jobs.settings.component.html
index f33b245c..ca76f1e5 100644
--- a/src/frontend/app/ui/settings/jobs/jobs.settings.component.html
+++ b/src/frontend/app/ui/settings/jobs/jobs.settings.component.html
@@ -24,16 +24,19 @@
                     *ngSwitchCase="JobTriggerType.scheduled">{{schedule.trigger.time | date:"medium"}}</ng-container>
                   <ng-container *ngSwitchCase="JobTriggerType.never" i18n>never</ng-container>
                   <ng-container *ngSwitchCase="JobTriggerType.after">
-                    <ng-container i18n>after</ng-container>:
+                    <ng-container i18n>after</ng-container>
+                    :
                     {{schedule.trigger.afterScheduleName}}
                   </ng-container>
                 </ng-container>
               </div>
               <div>
-                <button class="btn btn-danger job-control-button ml-0" (click)="remove(schedule)"><span class="oi oi-trash"></span>
+                <button class="btn btn-danger job-control-button ml-0" (click)="remove(schedule)"><span
+                  class="oi oi-trash"></span>
                 </button>
                 <app-settings-job-button class="job-control-button ml-md-2 mt-2 mt-md-0"
                                          (error)="error=$event"
+                                         [allowParallelRun]="schedule.allowParallelRun"
                                          [jobName]="schedule.jobName" [config]="schedule.config"
                                          [shortName]="true"></app-settings-job-button>
               </div>
@@ -51,10 +54,11 @@
                     {{backendTextService.getJobName(schedule.jobName)}}
                   </div>
                   <div class="col-md-6">
-                  <app-settings-job-button class="float-right"
-                                           [jobName]="schedule.jobName"
-                                           (error)="error=$event"
-                                           [config]="schedule.config"></app-settings-job-button>
+                    <app-settings-job-button class="float-right"
+                                             [jobName]="schedule.jobName"
+                                             [allowParallelRun]="schedule.allowParallelRun"
+                                             (error)="error=$event"
+                                             [config]="schedule.config"></app-settings-job-button>
 
                   </div>
                 </div>
@@ -121,6 +125,26 @@
                       [(timestamp)]="schedule.trigger.atTime"></app-timestamp-timepicker>
                   </div>
                 </div>
+                <div class="form-group row">
+                  <label class="col-md-2 control-label" [for]="'allowParallelRun'+i" i18n>Allow parallel run</label>
+                  <div class="col-md-10">
+                    <bSwitch
+                      class="switch"
+                      [name]="'allowParallelRun'+'_'+i"
+                      [id]="'allowParallelRun'+'_'+i"
+                      [switch-on-color]="'primary'"
+                      [switch-inverse]="true"
+                      [switch-off-text]="text.Disabled"
+                      [switch-on-text]="text.Enabled"
+                      [switch-handle-width]="100"
+                      [switch-label-width]="20"
+                      [(ngModel)]="schedule.allowParallelRun">
+                    </bSwitch>
+                    <small class="form-text text-muted"
+                           i18n>Enables the job to start even if an other job is already running.
+                    </small>
+                  </div>
+                </div>
               </div>
 
 
@@ -137,7 +161,6 @@
                     <ng-container [ngSwitch]="configEntry.type">
                       <ng-container *ngSwitchCase="'boolean'">
                         <bSwitch
-                          id="enableThreading"
                           class="switch"
                           [name]="configEntry.id+'_'+i"
                           [id]="configEntry.id+'_'+i"
diff --git a/src/frontend/app/ui/settings/jobs/jobs.settings.component.ts b/src/frontend/app/ui/settings/jobs/jobs.settings.component.ts
index f44370f5..9313a472 100644
--- a/src/frontend/app/ui/settings/jobs/jobs.settings.component.ts
+++ b/src/frontend/app/ui/settings/jobs/jobs.settings.component.ts
@@ -43,7 +43,8 @@ export class JobsSettingsComponent extends SettingsComponent<ServerConfig.JobCon
     jobName: '',
     trigger: {
       type: JobTriggerType.never
-    }
+    },
+    allowParallelRun: false
   };
 
   constructor(_authService: AuthenticationService,
@@ -118,7 +119,8 @@ export class JobsSettingsComponent extends SettingsComponent<ServerConfig.JobCon
       config: <any>{},
       trigger: {
         type: JobTriggerType.never
-      }
+      },
+      allowParallelRun: false
     };
 
     const job = this._settingsService.availableJobs.value.find(t => t.Name === jobName);
diff --git a/src/frontend/app/ui/settings/photo/photo.settings.component.html b/src/frontend/app/ui/settings/photo/photo.settings.component.html
index 74e6fe3c..9c0e966e 100644
--- a/src/frontend/app/ui/settings/photo/photo.settings.component.html
+++ b/src/frontend/app/ui/settings/photo/photo.settings.component.html
@@ -103,6 +103,7 @@
         <app-settings-job-button class="mt-2 mt-md-0 float-left"
                                  [soloRun]="true"
                                  (error)="error=$event"
+                                 [allowParallelRun]="false"
                                  [jobName]="jobName"></app-settings-job-button>
 
         <ng-container *ngIf="Progress != null">
diff --git a/src/frontend/app/ui/settings/scheduled-jobs.service.ts b/src/frontend/app/ui/settings/scheduled-jobs.service.ts
index 5ada4906..3d537e5c 100644
--- a/src/frontend/app/ui/settings/scheduled-jobs.service.ts
+++ b/src/frontend/app/ui/settings/scheduled-jobs.service.ts
@@ -41,14 +41,23 @@ export class ScheduledJobsService {
     return await this.loadProgress();
   }
 
-  public async start(jobName: string, config?: any, soloStart: boolean = false): Promise<void> {
-    this.jobStartingStopping[jobName] = true;
-    await this._networkService.postJson('/admin/jobs/scheduled/' + jobName + '/' + (soloStart === true ? 'soloStart' : 'start'),
-      {config: config});
-    // placeholder to force showing running job
-    this.addDummyProgress(jobName, config);
-    delete this.jobStartingStopping[jobName];
-    this.forceUpdate();
+  public async start(jobName: string, config?: any, soloStart: boolean = false, allowParallelRun = false): Promise<void> {
+    try {
+      this.jobStartingStopping[jobName] = true;
+      await this._networkService.postJson('/admin/jobs/scheduled/' + jobName + '/start',
+        {
+          config: config,
+          allowParallelRun: allowParallelRun,
+          soloStart: soloStart
+        });
+      // placeholder to force showing running job
+      this.addDummyProgress(jobName, config);
+    } catch (e) {
+      throw e;
+    } finally {
+      delete this.jobStartingStopping[jobName];
+      this.forceUpdate();
+    }
   }
 
   public async stop(jobName: string): Promise<void> {
@@ -70,7 +79,7 @@ export class ScheduledJobsService {
             this.progress.value[prg].state === JobProgressStates.cancelling)
         )) {
         this.onJobFinish.emit(prg);
-        this.notification.info(this.i18n('Job finished') + ': ' + this.backendTextService.getJobName(prevPrg[prg].jobName));
+        this.notification.success(this.i18n('Job finished') + ': ' + this.backendTextService.getJobName(prevPrg[prg].jobName));
       }
     }
   }
diff --git a/src/frontend/app/ui/settings/thumbnail/thumbnail.settings.component.html b/src/frontend/app/ui/settings/thumbnail/thumbnail.settings.component.html
index 6e5ea85e..bd1dea7f 100644
--- a/src/frontend/app/ui/settings/thumbnail/thumbnail.settings.component.html
+++ b/src/frontend/app/ui/settings/thumbnail/thumbnail.settings.component.html
@@ -78,6 +78,7 @@
                                [soloRun]="true"
                                (error)="error=$event"
                                [jobName]="jobName"
+                               [allowParallelRun]="false"
                                [config]="Config"></app-settings-job-button>
 
 
diff --git a/src/frontend/app/ui/settings/video/video.settings.component.html b/src/frontend/app/ui/settings/video/video.settings.component.html
index 15eabdd4..d6da35a9 100644
--- a/src/frontend/app/ui/settings/video/video.settings.component.html
+++ b/src/frontend/app/ui/settings/video/video.settings.component.html
@@ -130,6 +130,7 @@
       <app-settings-job-button class="mt-2 mt-md-0 float-left"
                                [soloRun]="true"
                                (error)="error=$event"
+                               [allowParallelRun]="false"
                                [jobName]="jobName"></app-settings-job-button>
 
       <ng-container *ngIf="Progress != null">