Why does my hard drive size appear smaller on Synology NAS?
At Storage Manager > Volume, the hard drive size appears smaller than that claimed by the HDD manufacturer, because file systems (of Synology NAS or regular computers) adopt the binary definition of storage units while HDD manufacturers adopt the decimal definition.
- Decimal definition (adopted by HDD manufacturers):
1 TB = 1000 GB; 1 GB = 1000 MB; 1 MB = 1000 KB; 1 KB=1000 Bytes
Therefore, 1 TB = 10004 Bytes, and 1 GB = 10003 Bytes - Binary definition (adopted by file systems):
1 TB = 1024 GB; 1 GB = 1024 MB; 1 MB = 1024 KB; 1 KB=1024 Bytes
Therefore, 1 TB = 10244 Bytes, and 1GB = 10243 Bytes
As a result, if you buy 2 hard drives labeled as 500 GB and 1 TB in storage capacity respectively, and install them on your Synology NAS, the actual sizes for each drive displayed on the Volume page will be as follows:
500 GB x 10003 / 10243 = 465 GB
1000 GB x 10003 / 10243 = 931 GB
Why does my SD card become read-only when unplugged from EDS14?
Please always eject your SD card and USB storage device before unplugging them from the EDS14. Improper unplugging can result in file system corruption and storage abnormality. If your EDS14 system database is stored on an SD card, hotplugging may render your device read-only.
To eject storage devices properly from EDS14, go to Control Panel > Devices and Printers to eject a specific device, or push the hardware SD/Disk Eject button to the side of your EDS14 to eject all connected devices at once. The storage LED indicator blinks when your device is being ejected and goes out when it has been successfully ejected.
Why can't I repair a volume with a new hard drive with the same capacity?
This usually happens when you replace the hard drive with a different brand and model. Mostly, the capacity of hard drives produced by different manufacturers differs, even though the hard drives are claimed to have the exact same capacity. We suggest replacing the hard drives either with the same brand and model or different brand and model but larger in capacity.
What's the maximum file size Synology NAS supports (for DSM 3.0 and onward)?
The EXT4 format which is used on the internal hard drive inside Synology NAS with DSM 3.0 and onward supports up to 16TB for a single file. For more details about EXT4 format, please refer to http://en.wikipedia.org/wiki/Ext4.
Besides EXT4, external hard drives connecting to Synology NAS can also be formatted in FAT32. FAT32 supports up to 4GB for a single file. For more details about FAT32 format, please refer to http://en.wikipedia.org/wiki/FAT32.
Is it necessary to defragment the internal hard drive of the Synology Product?
No.
Disk defragmenter is mainly used for FAT file systems. Because the speed of reading files will decrease after the FAT system has run for a period of time, it is necessary to run disk defragmenter to rearrange data to speed up/accelerate the speed of reading files.
It is not necessary to defragment the internal hard drive of the Synology Product because the Synology Product uses EXT4 file system, and it has made the best arrangement while assigning files.
How do I know when the internal hard drive of the Synology Product is full?
You can know the usage status of the internal hard drive by receiving messages sent by the system or on DSM desktop notifications. To set the system messages, please go to Main Menu > Control Panel > Notification to enable email, SMS, or push notification services. You will thereby receive messages informing the usage status of the internal hard drive of the Synology product .
Does the eSATA port of Synology products support eSATA disk enclosures with port multipliers?
Some Synology products come with eSATA port(s) for connecting external drives with the eSATA interface. Some disk enclosures utilize port multipliers to allow the installation of multiple hard drives in a single casing. However, please note that all Synology products do not support eSATA disk enclosures with port multipliers. Your hard drives installed on such devices might not be recognized by your Synology products. If you would like to use external disk enclosures with multiple hard drives, we recommend you use Synology Expansion Units. Please see the compatibility list here for more information.