diff --git a/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/capacity/CephOsdGroupCapacityHelper.java b/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/capacity/CephOsdGroupCapacityHelper.java
index ddd4c2f9901..f9dc2d01fe6 100644
--- a/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/capacity/CephOsdGroupCapacityHelper.java
+++ b/plugin/ceph/src/main/java/org/zstack/storage/ceph/primary/capacity/CephOsdGroupCapacityHelper.java
@@ -1,6 +1,7 @@
 package org.zstack.storage.ceph.primary.capacity;
 
 import org.apache.commons.collections.CollectionUtils;
+import org.apache.commons.lang.StringUtils;
 import org.springframework.beans.factory.annotation.Autowire;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Configurable;
@@ -238,7 +239,7 @@ public Long calculateAvailableCapacityByRatio(CephOsdGroupVO osdGroup, String pr
         for (String poolName : poolNames) {
             String installPathPrefix = String.format("ceph://%s", poolName);
             long volSize = volumes.parallelStream()
-                    .filter(v -> v.getInstallPath() != null && v.getInstallPath()
+                    .filter(v -> !StringUtils.isEmpty(v.getInstallPath()) && v.getInstallPath()
                             .substring(0, v.getInstallPath().lastIndexOf("/"))
                             .equals((installPathPrefix)))
                     .map(VolumeVO::getSize)
@@ -246,7 +247,7 @@ public Long calculateAvailableCapacityByRatio(CephOsdGroupVO osdGroup, String pr
                     .reduce(0L, Long::sum);
 
             long imageCacheSize = imageCaches.parallelStream()
-                    .filter(v -> v.getInstallUrl() != null && v.getInstallUrl()
+                    .filter(v -> !StringUtils.isEmpty(v.getInstallUrl()) && v.getInstallUrl()
                             .substring(0, v.getInstallUrl().lastIndexOf("/"))
                             .equals((installPathPrefix)))
                     .map(ImageCacheVO::getSize)
@@ -254,7 +255,7 @@ public Long calculateAvailableCapacityByRatio(CephOsdGroupVO osdGroup, String pr
                     .reduce(0L, Long::sum);
 
             long snapShotSize = snapshots.parallelStream()
-                    .filter(v -> v.getPrimaryStorageInstallPath() != null && v.getPrimaryStorageInstallPath()
+                    .filter(v -> !StringUtils.isEmpty(v.getPrimaryStorageInstallPath()) && v.getPrimaryStorageInstallPath()
                             .substring(0, v.getPrimaryStorageInstallPath().lastIndexOf("/"))
                             .equals((installPathPrefix)))
                     .map(VolumeSnapshotVO::getSize)
diff --git a/test/src/test/groovy/org/zstack/test/integration/storage/primary/ceph/xsky/capacity/CephXskyPoolCapacityCase.groovy b/test/src/test/groovy/org/zstack/test/integration/storage/primary/ceph/xsky/capacity/CephXskyPoolCapacityCase.groovy
index 356599909f6..4049b6a3c9c 100644
--- a/test/src/test/groovy/org/zstack/test/integration/storage/primary/ceph/xsky/capacity/CephXskyPoolCapacityCase.groovy
+++ b/test/src/test/groovy/org/zstack/test/integration/storage/primary/ceph/xsky/capacity/CephXskyPoolCapacityCase.groovy
@@ -51,6 +51,7 @@ class CephXskyPoolCapacityCase extends SubCase {
         env.create {
             testReconnectPrimaryStorage()
             testSkipCalculateCapacityWhichInstallPathIsNull()
+            testSkipCalculateCapacityWhichInstallPathIsEmpty()
         }
     }
 
@@ -205,4 +206,33 @@ class CephXskyPoolCapacityCase extends SubCase {
         SQL.New(VolumeSnapshotVO.class).eq(VolumeSnapshotVO_.uuid, rootSnapshot.uuid)
                 .set(VolumeSnapshotVO_.primaryStorageInstallPath, volumeSnapshotInstallPath).update()
     }
+
+    void testSkipCalculateCapacityWhichInstallPathIsEmpty() {
+        PrimaryStorageInventory ps = env.inventoryByName("ceph-pri") as PrimaryStorageInventory
+        VmInstanceInventory vm = env.inventoryByName("test-vm") as VmInstanceInventory
+
+        VolumeSnapshotInventory rootSnapshot = createVolumeSnapshot {
+            name = "root-volume-snapshot-empty-path"
+            volumeUuid = vm.rootVolumeUuid
+        } as VolumeSnapshotInventory
+
+        String volumeInstallPath = Q.New(VolumeVO.class).eq(VolumeVO_.uuid, vm.rootVolumeUuid).select(VolumeVO_.installPath)
+                .findValue()
+        String volumeSnapshotInstallPath = Q.New(VolumeSnapshotVO.class).eq(VolumeSnapshotVO_.uuid, rootSnapshot.uuid)
+                .select(VolumeSnapshotVO_.primaryStorageInstallPath)
+                .findValue()
+
+        // mock install path is empty string
+        SQL.New(VolumeVO.class).eq(VolumeVO_.uuid, vm.rootVolumeUuid).set(VolumeVO_.installPath, "").update()
+        SQL.New(VolumeSnapshotVO.class).eq(VolumeSnapshotVO_.uuid, rootSnapshot.uuid)
+                .set(VolumeSnapshotVO_.primaryStorageInstallPath, "").update()
+
+        reconnectPrimaryStorage {
+            uuid = ps.uuid
+        }
+
+        SQL.New(VolumeVO.class).eq(VolumeVO_.uuid, vm.rootVolumeUuid).set(VolumeVO_.installPath, volumeInstallPath).update()
+        SQL.New(VolumeSnapshotVO.class).eq(VolumeSnapshotVO_.uuid, rootSnapshot.uuid)
+                .set(VolumeSnapshotVO_.primaryStorageInstallPath, volumeSnapshotInstallPath).update()
+    }
 }