Why doesn't 6.3TB of disk hold 4.4TBs of data on my DS216J

[chriskhw]

Hi

This is probably the dumbest question ever asked on here but for the life of me I cant figure out whats going on

I have purchased a second hand ds216J. It has a 2.7TB and a 3.6TB disk configured as JBOD - so a total of 6.3TB

I formated the disks and made them into a single volume. Again it said 6.3TB

I instlled some packaages but not many

The web interface (and my windows laptop with a mapped drive to the NAS) still both report the capacity of 6.3TB

I had loaded files on and then deleted them but emptied the recycle bin

Windows and



I bought the NAS to replace loads of different external USB disks

The first disk I want to load onto the NAS is a USB disk, NTFS formatted, total capacity 4.54 TB (of which 3.9 TB of storage is used). Not using compression or anything (or at least doesnt say it is)

When I try to copy the USB to the NAS, it runs out of space with about 1.4TB still to copy

Can anyone please explain why?

Bad sectors? Reserved storage? Installed packages? Some other stuff I dont know about that reserves lots of space of the disk?

ANy help gratefully apprecited

Thanks

 

[EAZ1964]

can you share a screen print of the disk manager, showing the pool/volume setup?

Standard setup for Synology NAS is SHR with one disk redundancy. In your case that would be one volume of 2.7 mirrored storage. That sounds in the ballpark of what you see in your current setup (3.9-1.4 TB = 2.5 TB).
The windows reported capacity does not seem right then.

Evidence: JBOD storage is risky, if one of the disk fails (and that will happen one day) you will loose ALL the data.
See e.g.:

RAID Reliability Calculator | Simple MTTDL Model | ServeTheHome

ServeTheHome's RAID reliability calculator based on a simple MTTDL model based on a Poisson distribution and various user inputs about their environment

www.servethehome.com

There is a 1000times higher risk on dataloss for a JOBD than RAID1

 

[chriskhw]

Hi

Thanks for the reply

I think I did create the pool as JBOD with zero redundancy as I just wanted 5TB+ of capacity storage

Yes I know that a disk will fail one day but my plan was to use my existing USB external disks to attach to the NAS and then schedule regular backups from the NAS to those USB disks so I can restore in the event of a disk failure.

I attach a file showing disk configuration and capacity from the DSM and also, for interest, the WIndows Explorer capacity

To be honest I dont know what SHR is and if its some kind of default, is there a way to turn it off?

Thanks

 

[Telos]

JBOD storage is risky

WOW. I hear this so many times and yet nearly every laptop has non-redundant storage, and when that drive fails all data is lost. Why panic over a NAS and not a PC. A NAS backup can protect data loss as well.

 

[Telos]

When I try to copy the USB to the NAS, it runs out of space with about 1.4TB still to copy

According to your screenshot your 6.3 TB of NAS storage is fully used. Have you looked at File Station? Are shared folders empty? Or?

 

[EAZ1964]

WOW. I hear this so many times and yet nearly every laptop has non-redundant storage, and when that drive fails all data is lost. Why panic over a NAS and not a PC. A NAS backup can protect data loss as well.

Off topic, but anyway: a JOBD doubles the risk for full data loss compared to a single disk non redundant storage. So that is why I call it risky, I will be clear on this in future posts. Edited the previous post with objective data source.
Agree that if you have proper backup the risk is reduced.

On topic: agree with your post, it is clear that the disks are full.

 

[chriskhw]

According to your screenshot your 6.3 TB of NAS storage is fully used. Have you looked at File Station? Are shared folders empty? Or?

Hi

Apart from one package - Plex Media Server and the folder structure which contains 3.9TB of data from the external USB disk which only allows 2.5TB to be copied I have nothing else on the NAS. I dont have any shared folders on it.

File station - just shows the default but empty folders of photos, video and music, my own folder, and recycle which is also empty

The analysis of the disks themselves show them to be healthy

My understanding having formatted the disks in the NAS and craeated a single JBOD with no protection, no RAID etc would make the combined capacity of both drives available as storage

Is my understanding incorrect

I cant see what is using the space up

I did see something about version control so maybe thats using up space. But I can see any setting or anything in the DSM that even mentions it

Thanks

 

[chriskhw]

Ah

I found how to switch version control off

Doesnt seem to have made much difference sadly

 

[chriskhw]

I think I have found out what it is ... versioning
It seems the default number of previous versions by default it 8 versions (I am guessing thats the default becuase the previous owner had performed a factory reset)
Somewhere (and I wish I could remember where it was) my previous versions TB was taking up 2.6TB

So will do a factory reset, turn off versioning altogether, and try again

Thanks for your help

 

[Telos]

I think I have found out what it is ... versioning

If your system is ext4 formatted, Drive versioning will store an additional copy of every versioned file. So ... if you are versioning 500 MB of files, Drive versioning will copy that, adding another 500 MB storage load, even before you make a change to any of those files.

So ... either turn off versioning, or version only critical files ... or get much larger drives.

 

[Birdy]

On a Btrfs volume, Drive leverages snapshot technology to create copies of the present files in shared folders and store them in the database according to the copy-on-write principle.

Compared with the ext4 volume that requires a full copy of the present file in the database, the Drive database on a Btrfs volume contains only snapshots (for present files) and patches (for preceding files), thus saving the storage space up to 50% when storing historical file versions.

 

[chriskhw]

Thanks.

Just a shame I couldnt find a way to free up disk space released when I turned versioning off. There probably is a way I just couldnt find it

 

[Telos]

I couldnt find a way to free up disk space released when I turned versioning off. There probably is a way I just couldnt find it

Here's one way ... Stop Synology Drive. SSH into your NAS and delete the directory "@synologydrive". Then, exit from SSH and restart the Synology Drive server.

 

[chriskhw]

Thanks - I shall give that a go

Thanks and regards

 

[chriskhw]

Hi

So the user I am using to log in via SSH is an administrative rights user.

When I try the rm -rf @synologydrive I am getting access denied for every file.

Is there something else I need to do?

Thanks for your help again

 

[chriskhw]

Ah - you have to use sudo before it. Sorry, I'm not used to this sort of operating system

Thanks