# Unable to create a snapshot

**URL:** <https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039>\
**Category:** Product Support\
**Created:** [July 30, 2025, 7:07am UTC](https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039 "2025-07-30T07:07:21Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![kuz](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.opennebula.io/kuz/32/8621_2.png) [@kuz](https://forum.opennebula.io/u/kuz)\
**Post date:** [July 30, 2025, 7:07am UTC](https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039/1 "2025-07-30T07:07:21Z")

</div>

7.0.0version

When I was creating a snapshot, an error was prompted:

```auto
Wed Jul 30 14:51:30 2025 [Z0][VM][I]: New LCM state is HOTPLUG_SNAPSHOT
Wed Jul 30 14:51:31 2025 [Z0][VMM][I]: Command execution failed (exit code: 255): 'if [-x "/var/tmp/one/vmm/kvm/snapshot_create"]; then /var/tmp/one/vmm/kvm/snapshot_create 3cb71ec5-3d1e-42ff-b471-2250351d2cc9 0 6 10.9.200.6; else exit 42; fi'
Wed Jul 30 14:51:31 2025 [Z0][VMM][I]: error: unsupported configuration: internal snapshot for disk sda unsupported for storage type raw
Wed Jul 30 14:51:31 2025 [Z0][VMM][I]: Could not create snapshot for domain 3cb71ec5-3d1e-42ff-b471-2250351d2cc9.
Wed Jul 30 14:51:31 2025 [Z0][VMM][E]: SNAPSHOTCREATE: error: unsupported configuration: internal snapshot for disk sda unsupported for storage type rawCould not create snapshot for domain 3cb71ec5-3d1e-42ff-b471-2250351d2cc9.

```

I understand the error message that snapshots cannot be created for the raw format. However, I don’t know how to adjust the parameters. I’ve tried many methods (referring to “LVM Thin Internals LVM”) but still haven’t achieved the snapshot function. I need help.

> **[SAN Datastore](https://docs.opennebula.io/7.0/product/cluster_configuration/storage_system/lvm_drivers/#datastore-internals)**
>
> This storage configuration assumes that Hosts have access to storage devices (LUNs) exported by an Storage Area Network (SAN) server using a suitable protocol like iSCSI or Fibre Channel. The Hosts will interface the devices through the LVM...

The IMAGE DS storage is ultimately stored on the NFS node. The NFS shared disk is mounted to the manager1 node in the form of network mounting.

```auto
192.168.100.1:/data/nfs_share 5.2T 4.4G 5.2T 1% /var/lib/one/datastores
root@manager1:/opt/tp# cat ds_image_new.conf 
NAME = lvm_image
DS_MAD = fs
TM_MAD = fs_lvm_ssh
DISK_TYPE = "BLOCK"
TYPE = IMAGE_DS
LVM_THIN_ENABLE = YES
PERSISTENT_SNAPSHOTS = YES
SAFE_DIRS="/var/tmp /tmp /var/lib/one"

```

The SYSTEM DS uses LVM.

```auto
root@manager1:/opt/tp# vgs
  VG #PV #LV #SN Attr VSize VFree 
  vg-one-103 1 2 0 wz--n- <30.00t 29.96t
root@manager1:/opt/tp# cat ds_system.conf 
NAME = system_ds
TM_MAD = fs_lvm_ssh
TYPE = SYSTEM_DS
DISK_TYPE = BLOCK
LVM_THIN_ENABLE = YES
PERSISTENT_SNAPSHOTS = YES # This setting has no effect. It still shows "NO" in the system. 

```

Regards.

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<div class="post-metadata">

**Author:** ![atodorov\_storpool](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.opennebula.io/atodorov_storpool/32/5327_2.png) [@atodorov\_storpool](https://forum.opennebula.io/u/atodorov_storpool)\
**Post date:** [July 30, 2025, 2:28pm UTC](https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039/2 "2025-07-30T14:28:08Z")

</div>

AFAIK the VM Snapshots interface use libvirt functionality which works with qcow2 files only…

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<div class="post-metadata">

**Author:** ![kuz](https://yyz1.discourse-cdn.com/flex031/user_avatar/forum.opennebula.io/kuz/32/8621_2.png) [@kuz](https://forum.opennebula.io/u/kuz)\
**Post date:** [July 31, 2025, 1:29am UTC](https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039/3 "2025-07-31T01:29:40Z")

</div>

Thank you for your explanation. I can understand what you said. My original image file is in qcow format, but the image and virtual machine disk created through LVM will default to raw format. How should I modify it?

Should I let it default to raw format and adjust the parameters to meet LVM Thin for achieving the snapshot function?

I don’t know which solution is more suitable and how to adjust the parameters and choose the solution.

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<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex031/uploads/opennebula/original/2X/1/14d66f1130b9cd292905f575da9b68a9f574dd03.png) [@system](https://forum.opennebula.io/u/system)\
**Post date:** [August 30, 2025, 1:29am UTC](https://forum.opennebula.io/t/unable-to-create-a-snapshot/14039/4 "2025-08-30T01:29:50Z")

</div>

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