diff --git a/commands.go b/commands.go
index d8638b0..f3a3689 100644
--- a/commands.go
+++ b/commands.go
@@ -86,10 +86,16 @@ type configRoot struct {
 type cache struct {
 	CacheDir       string
 	Instances      []*compute.Instance
-	InstanceGroups []*compute.InstanceGroup
+	InstanceGroups []*instanceGroupExt
 	Projects       []*cloudresourcemanager.Project
 }
 
+type instanceGroupExt struct {
+	InstanceGroup *compute.InstanceGroup
+	Project       *cloudresourcemanager.Project
+	Members       []*compute.Instance
+}
+
 func loadCache() (*cache, error) {
 	cachedir, err := homedir.Expand("~/.cache/geco/")
 	if err != nil {
@@ -267,11 +273,11 @@ func doCache(cliCtx *cli.Context) {
 	}
 
 	// gcloud compute instance-groups list (in parallel)
-	instanceGroupNotify := make(chan []*compute.InstanceGroup)
+	instanceGroupNotify := make(chan []*instanceGroupExt)
 	for _, project := range c.Projects {
-		go func(project *cloudresourcemanager.Project, notify chan<- []*compute.InstanceGroup) {
+		go func(project *cloudresourcemanager.Project, notify chan<- []*instanceGroupExt) {
 			semaphore <- 0
-			var instanceGroups []*compute.InstanceGroup
+			var ret []*instanceGroupExt
 
 			log.Printf("loading instance groups in %s (%s)...\n", project.Name, project.ProjectId)
 			service, err := compute.New(client)
@@ -294,7 +300,12 @@ func doCache(cliCtx *cli.Context) {
 				}
 
 				for _, instanceGroupsScopedList := range res.Items {
-					instanceGroups = append(instanceGroups, instanceGroupsScopedList.InstanceGroups...)
+					for _, instanceGroup := range instanceGroupsScopedList.InstanceGroups {
+						ret = append(ret, &instanceGroupExt{
+							InstanceGroup: instanceGroup,
+							Project:       project,
+						})
+					}
 				}
 
 				if res.NextPageToken != "" {
@@ -306,9 +317,9 @@ func doCache(cliCtx *cli.Context) {
 			}
 
 			<-semaphore
-			notify <- instanceGroups
+			notify <- ret
 
-			log.Printf("loaded instances in %s (%s), %d instances found.\n", project.Name, project.ProjectId, len(instanceGroups))
+			log.Printf("loaded instance groups in %s (%s), %d instances found.\n", project.Name, project.ProjectId, len(ret))
 		}(project, instanceGroupNotify)
 	}
 	for _ = range c.Projects {
@@ -318,16 +329,13 @@ func doCache(cliCtx *cli.Context) {
 		}
 	}
 
-	// sort projects, instances, instance-groups
+	// sort projects, instances
 	sort.Slice(c.Projects, func(i, j int) bool {
 		return c.Projects[i].ProjectId < c.Projects[j].ProjectId
 	})
 	sort.Slice(c.Instances, func(i, j int) bool {
 		return c.Instances[i].SelfLink < c.Instances[j].SelfLink
 	})
-	sort.Slice(c.InstanceGroups, func(i, j int) bool {
-		return c.InstanceGroups[i].SelfLink < c.InstanceGroups[j].SelfLink
-	})
 
 	saveCache(c)
 	log.Println("saved cache.")