QNAP Systems Ts 253 User Guide

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LUN Usage Light blue: Allocated 
Red line: Alert threshold 
 
For details on Storage Pools, Volumes, and RAID Groups, refer to the following links:  
Storage Pools 
Volumes 
RAID Groups  
						

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Storage Pools 
 
A storage pool is designed to aggregate physical hard disk drives into a large storage space and to 
provide enhanced RAID protection for it. You can perform the following actions to manage storage 
pools:  
Creating New Storage Pools 
Removing Storage Pools 
Safely Detaching Storage Pools 
Expanding Storage Pools 
Setting a Threshold 
Setting Snapshot Reservation 
Creating New Volumes for Storage Pools 
Creating New iSCSI LUNs for Storage Pools 
 
Note:  
Storage Pools are not supported by some NAS models. Please refer to the QNAP 
website, product information, and software specifications for more details.  
For RAID groups that contain 16 hard drives, up to 512MB RAM will be used for them. 
1GB RAM is recommended for 24-32 hard drives. 
  
Creating New Storage Pools 
  
Follow these steps to create a new storage pool: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Click Create > New Storage Pool. 
3. Select the enclosure unit, hard disk drive(s), RAID type and hot spare disk and click Create. 
4. Set the percentage of storage spool space that is reserved to store snapshots.  
5. Please note that all data on the selected hard disk drive(s) will be erased. Click OK if you are 
certain about this. 
6. A new storage pool will be created. 
 
Removing Storage Pools 
  
Follow these steps to remove a storage pool: 
Go to Storage Manager > STORAGE > Storage Space.  
Double click a storage pool to be removed to bring up the Storage Pool Management page. 
Click Remove > Remove Pool. 
Click Apply.  
						

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The selected storage pool will be removed. 
 
Note: Before you remove a storage pool, be sure to remove all volumes and LUNs on that 
storage pool. 
 
Safely Detaching Storage Pools 
 
Follow these steps to safely detach a storage pool: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool to be removed to bring up the Storage Pool Management page. 
3. Click Remove > Safely Detach Pool. 
4. Click Apply. 
5. The selected storage pool will be removed. 
 
Note: After a storage pool is reattached, the configurations of iSCSI LUNs mapped in the 
storage pool or Apps installed before the detachment will not be automatically recovered. 
   
Expanding Storage Pools 
  
Follow these steps to expand a storage pool: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool to be expanded to bring up the Storage Pool Management page. 
3. Click Expand Pool.    
4. Select to create and add a new RAID group. Select Adding new hard drive(s) to an existing RAID 
group(the option Create new RAID groups will be covered in the following section), choose an 
existing RAID group from the drop-down list and click Next.  
5. Select the hard drive(s) to expand the storage pool and click Next. 
6. Click Expand. 
7. Please note that all data on the selected hard disk drive(s) will be erased. Click OK if you are 
certain about this. 
8. The chosen storage pool will be expanded. 
 
Note: New disks cannot be inserted into existing RAID groups of storage pools for specific 
RAID types (such as RAID 0, RAID 10, Single or JBOD). You must create an additional 
RAID group to expand those storage pools. 
  
Expanding storage pools by creating new RAID groups 
Follow these steps to create a RAID group for storage pool expansion: 
1. Go to Storage Manager > STORAGE > Storage Space.   
						

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2. Double click a storage pool to be expanded to bring up the Storage Pool Management page. 
3. Click Expand Pool, select Create and add a new RAID group and click Next. 
4. Select the enclosure unit, hard disk drive(s), RAID type and hot spare disk and click Next. 
5. Please note that if the type of the newly-created RAID group is different from that of the existing 
RAID group(s), the performance of the entire storage pool may be affected. To continue, click 
OK. 
6. Click Expand. 
7. Please note that all data on the selected hard drive(s) will be erased. Click OK if you are certain 
about this.    
8. The chosen storage pool will be expanded. 
 
Note:  
RAID 0, JBOD or Single RAID Group cannot be added to a storage pool if that storage 
pool already contains RAID 1, 5, 6, or 10.    
It is recommended to set an independent storage pool on a JBOD and only add new 
disks to that JBOD (or replace the existing disks in that JBOD) when expanding the 
storage pool. Otherwise, data stored on that JBOD will become inaccessible when 
connecting that JBOD to a different NAS host. 
 
Expanding storage pools by replacing hard disk drives in a RAID array 
With this function, RAID group capacity can be expanded by replacing hard disk drives in an array 
one by one. This option is supported for the following RAID types: RAID 1, RAID 5, RAID 6 and RAID 
10. Follow these steps to expand a RAID group: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool to be expanded to bring up the Storage Pool Management page. 
3. Select a RAID group and click Manage > Replace Disks One by One. 
4. Select at least one hard disk drive and click Change. After the description displays Please 
remove this drive, remove the hard disk drive from the NAS or expansion enclosure.        
5. After the description displays You can replace this drive, plug in the new hard disk drive to the 
drive slot.  
6. Repeat steps 4 and 5 until all hard drives have been replaced.  
7. Click Expand Capacity to continue. Click Yes. 
8. The chosen RAID group is expanded. 
 
Note: Available RAID management operations are detailed in the chapter on RAID 
Groups.  
  
 
  
						

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Setting a Threshold 
  
The system will generate a warning message in system logs when the storage pool used size hits the 
threshold. To set a threshold value for a storage pool, follow these steps: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool to set a threshold to bring up the Storage Pool Management page. 
3. Click Actions > Set Threshold.  
4. Enter a value for alert threshold and click Apply. 
  
Setting Snapshot Reservation 
 
You can set snapshot reservation space to ensure enough space for saving snapshots. Snapshot 
reservation is set as a percentage of total storage pool space and there are two scenarios:  
When the snapshot reserve is set to 0%, new snapshots taken will all be saved to a storage pool 
until that storage pool runs out of its space. When that happens, the system will start recycling 
older snapshots regardless the snapshot limitation set in Snapshot Global Settings.  
When the snapshot reserve is set to a value greater than 0%, this reserved space will be 
dedicated entirely to snapshots. The free space in a storage pool will be lower after the value is 
set and the snapshots will only use the space reserved. When the space used for snapshots 
exceeds the snapshot reserve, the system will start recycling older snapshots regardless the 
snapshot limitation set in Snapshot Global Settings.  
To set snapshot reservation, follow these steps:  
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool to set reserved space for snapshots and to bring up the Storage Pool 
Management page. 
3. Click Actions > Set Snapshot Reserved, enter a value for snapshot reserved space, and click 
Apply. 
 
Note:  
For more Snapshot details, refer to the Snapshot section in the Volumes chapter.  
The function or its content is only applicable on some models. To check for applicable 
models, please refer to the product comparison table on the QNAP website. 
o A minimum of 4 GB RAM is required to use snapshots. 
o x51 series models only support up to 256 snapshots instead of 1024. The HS-251 
does not support snapshots. 
  
Creating New Volumes for Storage Pools 
  
To create a new volume for a storage pool, follow these steps:   
						

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1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool. 
3. Click Create> New Volume. Follow the onscreen instructions to finish the creation process. For 
more details, please refer to the Volumes section. 
  
Creating New iSCSI LUNs for Storage Pools 
  
To create a new iSCSI LUN for a storage pool, follow these steps: 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a storage pool. 
3. Click Create> New iSCSI LUN. Follow the onscreen instructions to finish the creation process. 
For more details, please refer to the iSCSI Storage section.  
						

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Volumes 
 
A volume is formatted by the file system to store share folders and files. Users can manage, monitor, 
create, or delete a logical volume on this page. The following topics are covered in this chapter: 
Creating New Volumes 
Removing Volumes 
Expanding Volumes 
Available Volume operations 
Configuring Alert Threshold 
Check File System 
Creating New Shared Folders 
Snapshot 
Managing Previous Versions in Windows 
Encryption 
Setting Thin Provisioning Space Reclamation and SSD Trim  
 
Creating New Volumes 
 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Click Create > New Volume to launch the volume creation wizard. 
3. Configure the mode for the volume from static single, thick multiple, and thin multiple according 
to your needs (learn more about Thick or Thin Volumes in the following section) and click 
Next. 
4. Select the enclosure unit, hard disk drive(s), RAID type and hot spare disk for the volume to be 
created and click Next. 
5. Set the alert threshold and volume alias. You can also click File system option to specify bytes 
per inode, check the maximum volume size and number of files/folders, enable volume encryption, 
and create share folders. Click Next. 
Bytes 
per 
Inode 
Max. Size of Volume Max. Number of Files/Folders 
4096 15.99 TB Volume Size/Bytes per Inode 
8192 31.99 TB 
16384 
(Default
63.99 TB  
						

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Bytes 
per 
Inode 
Max. Size of Volume Max. Number of Files/Folders 
) 
32768 127.99 TB 
65536 250 TB 
 
6. Confirm your settings and click Finish. 
7. Please note that all data on the selected hard drive(s) will be erased. Click OK if you are certain 
about this. 
8. The new volume will be created. 
  
Note: The hot spare disk feature is only available for RAID 1, RAID 5, RAID 6 and RAID 
10. For other RAID types, the hot spare disk field will be grayed out. 
 
Follow these steps to create a new, thick or thin volume: 
1. Select Thick Multiple Volume or Thin Multiple Volume. Select to create a new storage pool or 
from an existing storage pool and click Next. 
2. Configure the mode for the volume from static single, thick multiple, and thin multiple according 
to your needs. 
3. Configure the volume capacity, alert threshold, volume alias, Bytes per inode, encryption and 
shared folder settings and click Next. 
4. Click Finish. 
5. A new volume will be created. 
 
Note:  
Static Single Volume: This mode offers the best performance but does not support 
thin provisioning, space reclamation and snapshots. For this option, the RAID group 
itself is a volume. 
Thick Multiple Volumes: This method can create multiple volumes on the same 
storage pool and instantly allocate physical storage space for the volume. It has better 
performance than thin volumes while also offering flexibility. 
Thin Multiple Volumes: Thin Multiple Volumes: This method can over-allocate the 
volume capacity for each volume regardless of the physical storage limit. Disk space is 
only used when files are written to the volume. After files are deleted, this space can 
be reclaimed for increasing the free space of the storage pool. The maximum size of 
thin multiple volumes is 20 times that of the storage pools free space. With thin  
						

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provisioning, volume space is fully utilized. 
A thick volume is usually more efficient for high frequency read/write activities. 
Because the space has been allocated for the volume, the predicament of insufficient 
physical space can be avoided, but the use of space is relatively inefficient. 
NAS models that do not support Storage Pools can only create Static Single Volumes. 
Please refer to the QNAP website, product information, and software specifications for 
more details.  
 
Removing Volumes 
 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a volume to be removed to bring up the Volume Management page. 
3. Click Remove. Click Apply and the selected volume is removed. 
 
Expanding Volumes 
 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a volume to be expanded to bring up the Volume Management page. 
3. Click Expand Volume.  
4. Enter the desired capacity or click Set to Max to allocate the maximum available space for the 
volume and click Apply. (Set to Max is only available for thick provisioned volumes.) 
5. The capacity of the volume will be expanded. 
 
Available Volume Operations 
 
After you go to Storage Manager > STORAGE > Storage Space, click Actions and choose to 
configure the threshold and cache settings, check the file system of a volume, rename volume alias, 
reclaim volume space, create a new share folder, format a volume, or manage snapshots. 
Note:  
All the data on a disk will be erased if it is formatted. Please use the Format feature 
with caution. 
For encryption related options (Change, Download, Save, Lock this Volume), refer to 
Encryption. 
The function or its content is only applicable on some models. To check for applicable 
models, please refer to the product comparison table on the QNAP website. 
o A minimum of 4 GB RAM is required to use snapshots. 
o x51 series models only support up to 256 snapshots instead of 1024. The HS-251 
does not support snapshots.  
						

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Configuring Alert Threshold 
 
The alert threshold is used to remind users when the capacity of a chosen volume is used up to the 
specified threshold level. A warning message will pop up when the specified threshold is reached. 
To set an alert threshold, select a volume in Storage Space to bring up the Volume Management 
page, click Actions > Set Threshold, enter the threshold level and click Apply. The alert 
threshold is set. 
 
Check File System 
 
If you receive the error message File system is not clean, the NAS may have suffered an abnormal 
shutdown. The system data or files that were being used while the shutdown occurred may have 
been corrupted. To check the file system and repair possible errors, go to Storage Manager > 
Storage Space. 
 
 
Creating New Shared Folders 
 
1. Go to Storage Manager > STORAGE > Storage Space.  
2. Double click a volume to bring up the Volume Management page.  
3. Click Actions > Create New Shared Folder. 
4. Specify the folder name and description of the new shared folder and select the disk volume for 
the shared folder. 
5. Click Edit to the right of Configure access privileges for users in Step 4 and specify user 
privileges. 
6. Click Edit to the right of Advanced settings in Step 4 and configure the guest access right, 
hidden folder, Oplocks, recycle bin and path. Click Create. 
7. A new shared folder will be created. 
 
Snapshot 
 
Users can take a snapshot, manage snapshots (revert, delete, and clone a snapshot, set up snapshot 
schedules, or restore snapshot files for LUNs or volumes), or replicate volumes/LUNs between 
different remote servers using snapshot technology.  
 
Note:  
Snapshot Replica (or volumes/LUNs replication between remote servers) is covered in 
Backup Station. For details, please refer to the Snapshot Replica chapter in Backup