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How to Expand Volumes or Disk Groups by Replacing Hard Disks on Synology NAS
Overview
Synology DiskStation is designed to grow with your changing storage needs, allowing you to create volumes or Disk Groups using smaller hard disks and then gradually expand them by replacing existing hard disks with ones of larger size. This feature allows you to expand storage capacity according to your budget and with no need to worry about losing existing data.
This article will guide you through the process of expanding a volume or Disk Group by replacing existing hard disks.
Contents
1. Before You Start
This article assumes that you have already done the following:
- Created at least one volume or Disk Group on your DiskStation.
- Prepared at least one new hard disk with which you can expand your existing volume or Disk Group.
- Prepared an external hard drive or network computer ready to temporarily back up your existing data (only for single-bay Synology products).
For information about basic hardware and software setup, please refer to the Quick Installation Guide for your Synology product. You can also see Synology DiskStation User's Guide (available at Download Center) for additional information related to this article.
- Back Up Data: Although the expansion process will not delete any existing data, we strongly recommend backing up your data before proceeding.
- Volume or Disk Group Status: Before beginning, make sure the status of your volume or Disk Group is Normal. If not, you must first repair it (For detailed instructions, please refer to this tutorial).
- Is data still accessible during expansion? Data on your system will be available while expanding volumes or Disk Groups; although the system may suspend connections temporarily when first starting the process.
2. Expanding Volumes or Disk Groups by Replacing Hard Disks
With DiskStation, you can expand volumes or Disk Groups by replacing smaller hard disks with larger ones. This process differs depending on your Synology product or the volume’s RAID type. Please see the sections below for instructions regarding different types of DiskStation or RAID types.
2.1 For Configurations Without Data Redundancy
Depending on your configurations, your volume or Disk Group might not have data redundancy, such as in the following situations:
- Your volume or Disk Group is created on a 1-bay DiskStation model.
- Your volume or Disk Group is Basic, RAID 0, JBOD, or any other configuration which does not provide data redundancy.
If your volume or Disk Group matches one of the situations above, you must be careful to back up all data and system configurations on your DiskStation before replacing any hard disks.
To replace hard disks for configurations without data redundancy:
- Back up data and system configurations of your DiskStation to an external storage device. For detailed instructions, please refer to this tutorial.
- Turn off your DiskStation.
- Replace old hard disks with new ones.
Important:
To avoid harming yourself or damaging your DiskStation, please follow the hard disk installation instructions found in the Quick Installation Guide for your Synology product. - Turn on your DiskStation.
- Reinstall DSM (DiskStation Manager) on your DiskStation. The latest version of DSM can be downloaded at Synology's Download Center.
- Create a new volume or Disk Group (see this tutorial for instructions).
- Go to Main Menu > Backup and Restore > Restore and restore the data and system configurations you just backed up to the external device.
- Once data has been fully restored, you can start using the newly expanded volume!
2.2 For SHR, RAID 1, RAID 5, and RAID 6
SHR, RAID 1, RAID 5, and RAID 6 types support data redundancy. If your volume or Disk Group uses one of these RAID types, you can easily expand capacity by replacing smaller hard disks with larger ones. When expanding these volume types, you must be careful to replace all hard disks one-by-one. After replacing one hard disk, you must repair the volume or Disk Group before replacing the next one. For RAID 1, RAID 5, and RAID 6, volume capacity will expand once all hard disks have been replaced.
Before replacing any hard disks, please note the guidelines below.
RAID 5 and RAID 6: When replacing hard disks of RAID 5 or RAID 6 volumes or Disk Groups, the smallest hard disk should always be replaced first. The storage capacity of RAID 5 volumes is (number of hard disks – 1) x (smallest hard disk size), and RAID 6 is (number of hard disks – 2) x (smallest hard disk size). Therefore, the smallest hard disk should always be replaced first in order to maximize hard disk usage.
For example, if your RAID 5 volume contains three hard disks that are 4 TB, 3 TB, and 2 TB respectively, the available capacity of your volume will be 4 TB. If you replace the 4 TB or 3 TB disks, the capacity of the volume will not change. To increase the capacity of your volume, the 2 TB hard disk must be replaced first.
SHR (Synology Hybrid RAID): When replacing hard disks belonging to SHR volumes or Disk Groups, please note the following:
- If the capacity of all member hard disks is equal, then you should replace at least two hard disks. Otherwise, the capacity of your volume will not expand.
For example, if your SHR volume consists of three 3 TB hard disks, then you must replace at least two hard disks in order to expand volume capacity. - If the capacity of member hard disks is different, then the new, replacement hard disks should be equal to or larger than the largest existing hard disk. In addition, you should replace smaller member hard disks first in order to optimize capacity usage.
For example, if your SHR volume consists of three hard disks that are 4 TB, 3 TB, and 2 TB respectively, then your new, replacement hard disks should be at least 4 TB. In addition, you should replace the 3 TB or 2 TB hard disks.
Replace hard disks for SHR, RAID 1, RAID 5, and RAID 6:
- Turn off your DiskStation (skip this step if your DiskStation supports hot-swapping).
- Remove the outer casing from your DiskStation.
Important:
To avoid harming yourself or damaging your DiskStation, please follow the hard disk installation instructions found in the Quick Installation Guide for your Synology product. - Replace one of the old hard disks with a new one you have prepared.
- Turn on your DiskStation.
- Login to DSM with an account belonging to the administrators group.
- Go to Main Menu.
- Open Storage Manager.
- Go to the Volume tab.
- The status of your volume should be Degraded. If your DiskStation is emitting a beep sound, you may press Beep Off.
- If you are expanding a volume, please go to Main Menu > Storage Manager > Volume, select the degraded volume, and click Manage. Then continue to Step 10.
- If you are expanding a Disk Group, please go to Main Menu > Storage Manager > Disk Group, select the degraded Disk Group, and click Manage. Then continue to Step 10.
- If you are expanding a volume, please go to Main Menu > Storage Manager > Volume, select the degraded volume, and click Manage. Then continue to Step 10.
- Select Repair and click Next.
- Select the hard disk you wish to add to the volume or Disk Group. You can add a hard disk by checking the corresponding checkbox. Then click Next to continue.
- A warning will appear, reminding you to make sure there is no important data on the selected hard disk. All existing data on the hard disk will be erased during expansion. Click Yes to continue.
- Review your settings on the confirmation screen. You can click Back to return and modify settings, or click Apply to finish the wizard and start the repair and expansion process.
- If you wish to check the status of the repair and expansion process, please go to Main Menu > Storage Manager > Disk Group or Volume.
- Once the repair process has finished, the volume status should be Normal.
- Repeat the above process until you have replaced all of the old hard disks.
2013-03-25 15:25:03