Snapshots
This page allows you to take, remove, and edit snapshots, as well as to configure snapshot schedule and retention settings.
You can store up to 256 snapshot copies at one time for each shared folder or iSCSI LUN. Snapshots minimize disk consumption by preserving individual blocks rather than whole files. Extra space may be consumed when the files in shared folders or blocks in iSCSI LUNs are updated or removed.
Shared Folder
To take a snapshot for a shared folder:
- Select the shared folder of which you wish to take a snapshot.
- Click Take a Snapshot.
- Enter the description in Description for the snapshot to be taken.
- Tick/untick the Lock checkbox to determine whether the snapshot will ignore the retention settings when automatic removal is to be triggered.
- Click OK to start taking a snapshot.
Note:
- Among settings in Control Panel > Shared Folder > Edit page, only the Windows ACL permission will be recorded in a snapshot.
To browse the snapshots of shared folders:
- Select a shared folder you wish to browse the snapshots of.
- Click Snapshot List.
- Select a snapshot you wish to browse, and click Browse.
Note:
- Snapshot Browse is not available for encrypted shared folders.
- If you are not able to browse the snapshot, please go to Control Panel > Shared Folder > Edit to enable the Make snapshot visible.
To remove the snapshots of shared folders:
- Select a shared folder you wish to remove the snapshots of.
- Click Snapshot List.
- Select one or more snapshots you wish to remove, and click Remove. (Press and hold Shift or Ctrl while making multiple selections.)
- You will see a confirmation message. Click Delete to confirm the removal.
To edit the snapshots of shared folders:
- Select a shared folder you wish to edit the snapshots of.
- Click Snapshot List.
- Select a snapshot you wish to edit, and click Edit.
- You can modify the description of the snapshot in Description, and tick/untick the Lock checkbox to determine whether the snapshot will ignore the retention settings when automatic removal is to be triggered.
- Click OK to save your settings.
To configure scheduled snapshots:
With scheduled snapshots, Snapshot & Replication will automatically take snapshots at the pre-determined time and frequency, and it will thus lighten your workload to take snapshot manually.
- Select a shared folder.
- Click Set Schedule.
- In the Schedule tab, tick the Enable snapshot schedule checkbox, and set up the time and frequency to take snapshots. To cancel scheduled snapshots for this shared folder, please untick the checkbox.
- Click OK to save your settings.
- You will see a confirmation message. Click OK to confirm the configuration.
Note:
- Scheduled snapshots' configuration will not be included in the Control Panel > Update & Restore > Configuration Backup feature.
To configure the retention settings for the scheduled snapshots:
- Select a shared folder.
- Click Set Schedule.
- Select Retention tab.
- Configure your retention settings. Choose any of the following options:
- Remove old snapshots upon reaching the limit: When the maximum number of snapshots is reached, the oldest snapshots will be overwritten by newly taken ones.
- Always retain snapshots: When the maximum number of snapshots is reached, Snapshot & Replication will stop taking new snapshots without removing the ones already taken.
- Retain snapshots with the following policy: You can configure retention rules for spcified time ranges. For more information, please refer to the Retention Policy note.
- Click OK to save your settings.
Note:
- Changing the retention settings will affect the equivalent settings in the Replication page.
iSCSI LUN
To take a snapshot for an iSCSI LUN:
- Select the iSCSI LUN of which you wish to take a snapshot.
- Click Take a Snapshot.
- Enter the description in Description for the snapshot to be taken.
- From the Lock drop-down list, select Yes/No to determine whether the snapshot will ignore the retention settings when automatic removal is to be triggered.
- Click OK to start taking a snapshot.
To remove a snapshot of an iSCSI LUN:
- Select an iSCSI LUN you wish to remove the snapshots of.
- Click Snapshot List.
- Select one or more snapshots you wish to remove, and click Remove. (Press and hold Shift or Ctrl while making multiple selections.)
- You will see a confirmation message. Click Yes to confirm the removal.
To edit a snapshot of an iSCSI LUN:
- Select an iSCSI LUN you wish to edit the snapshots of.
- Click Snapshot List.
- Select a snapshot you wish to edit, and click Edit.
- You can do any of the following to edit the snapshot:
- Change the description of the snapshot in Description.
- Select the Consistent state if application-consistent snapshot is enabled.
- Switch between Yes/No from the Lock drop-down list to determine whether the snapshot will ignore the retention settings when automatic removal is to be triggered.
- Click OK to save your settings.
To configure scheduled snapshots:
With scheduled snapshots, Snapshot & Replication will automatically take snapshots at the pre-determined time and frequency, and it will thus lighten your workload to take snapshot manually.
- Select an iSCSI LUN.
- Click Set Schedule.
- In the Schedule tab, tick the Enable snapshot schedule checkbox, and set up the time and frequency to take snapshots. To cancel scheduled snapshots for this shared folder, please untick the checkbox.
- Click OK to save your settings.
To configure the retention settings for the scheduled snapshots:
- Select an iSCSI LUN.
- Click Set Schedule.
- Select Retention tab.
- Configure your retention settings. Choose any of the following options:
- Remove old snapshots upon reaching the limit: When the maximum number of snapshots is reached, the oldest snapshots will be overwritten by newly taken ones.
- Always retain snapshots: When the maximum number of snapshots is reached, Snapshot & Replication will stop taking new snapshots without removing the ones already taken.
- Retain snapshots with the following policy: You can configure retention rules for spcified time ranges. For more information, please refer to the Retention Policy note.
- Click OK to save your settings.
- You will see a confirmation message. Click OK again to confirm the configuration.
To configure the consistent state of your iSCSI LUN snapshots:
- Select an iSCSI LUN.
- Click Set Schedule.
- Select Application tab.
- Tick/untick Enable application-consistent snapshots checkbox to switch between the following consistent states:
- Application consistent: Snapshots in this consistent state can be taken only when Synology Snapshot Manager is installed on your Windows server or VMware vCenter Server depending on your operating environment to communicate with DSM. When application-consistent snapshots are triggered on DSM, applications will be notified, and flush all the data from memory to the LUNs to be taken a snapshot of, hence the assurance of data consistency.
Note:
- If Synology Snapshot Manager has not been installed on your operating environment, the application-consistent snapshot will remain disabled even if the checkbox is ticked.
- Crash consistent: If Synology Snapshot Manager has not been installed on any of your clients, you can only capture crash-consistent snapshots of LUNs. When crash-consistent snapshots are triggered, applications will not be notified to flush the data from memory to the LUNs, hence the inability to guarantee data consistency.
- Click OK to save your settings.
Note:
- Changing the consistent state settings will affect the equivalent settings in the Replication page.
____
Retention Policy
This option provides an ideal solution to help you specify the maximum amounts of snapshot versions to save your volume space, but you may need to retain your snapshots for longer periods of time.
Synology employs the GFS, or Grandfather-Father-Son retention policy. You can configure the maximum amounts of snapshot versions to be retained for the following time ranges respectively: hourly, daily, weekly, monthly, and yearly.
Snapshot & Replication will retain as many as the configured maximum number of snapshots for every time range. If more than one snapshot verison exists within a time range, only the earliest one will be kept. For example, if you set a policy as 10 weekly snapshot(s), Snapshot & Replication will retain the earliest snapshot (if more than one snapshot is taken in a week) for each of the latest 10 weeks.
Moreover, all snapshot versions within one hour since the taking of newest snapshot will be kept by default, for your convenience to find and restore from recent snapshot versions. You can also lock a snapshot to prevent it from automatic removal by your retention rules.