Question Expanding Storage in SHR and using full capacity?

Tomnook80

Active Member
Hi all,

I'm still learning a lot about networking and wondering if I've made a basic error? I've set up my Synology 920+ initially with a 3TB disc in SHR format, as I understood that was the most flexible. Today I've added another 4TB. When I use the raid calculator: RAID Calculator | Synology Inc. it shows as 3TB usable, 3TB for protection and 1TB used. This is not how I wanted it set up at all, since all of my data is backed up elsewhere and I don't need anything backed up. I want to use the full 7tb space. The NAS is currently running it's parity consistency check which will take about 8 hours. Am I going to have to wipe everything and use a RAID0 config, which looking at the RAID calculator will work as I want it to? Or is there a way to expand the 3TB and 4TB configuration to have it use the full 7TB space in SHR?

Thanks in advance
 

mickevh

Distinguished Member
First the AVF Mantra: RAID is redundancy, not backup. Some RAID versions don't even offer redundancy.

If you want to maximise your storage, then there's probably no point using any RAID, just spin them up as plane Jane discs (often called JBOD - Just a Bunch Of Discs) rather than RAID0 (or anything RAID0 like.) RAID0 distributes the blocks of the volumes across the physical discs (without any redundancy) which has the consequence that when any disc dies, (they all die in the end,) you loose the data on all them!

Others familiar with your platform will doubtless comment on the specifics of how to transition from SHR to JBOD.
 

Tomnook80

Active Member
Thank you buddy. Methinks I should have researched a little more carefully before choosing SHR! So I guest the next question is how to change to JBOD...after waiting for about 6 more hours :/

EDIT: On reflection, I'm considering just picking up another 4TB to get the 7TB space I need and then have the 4TB for protection as, as you point out, they will all die in the end so worth having it set up to replace one by one if that was the case rather than have to start everything again.
 
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Tomnook80

Active Member
I've picked up a 4TB to keep the SHR as it seems like a safe bet, well, a safer bet than not having any protection! Lesson learnt I reckon :)
 

Sloppy Bob

Distinguished Member
If you're using SHR then you're using RAID, just the Synology version of RAID 5 (if, as I suspect, you're using SHR-1). So you're always going to have a redundant disc.

Using SHR-1, in order to get the full size from all your discs you will always need 2 of the largest drive installed. So if you bought and added a 10TB disk it would only be seen as a 4TB until you added another 10TB disk, then one of the 10TBs would be your redundant drive.

If you're adding a lot of data to your NAS I can't help but think you've gone too small with the drives, by the time you've added another 4TB to fill it you've only got a 10TB NAS + the Redundant Drive.
 

Tomnook80

Active Member
If you're using SHR then you're using RAID, just the Synology version of RAID 5 (if, as I suspect, you're using SHR-1). So you're always going to have a redundant disc.

Using SHR-1, in order to get the full size from all your discs you will always need 2 of the largest drive installed. So if you bought and added a 10TB disk it would only be seen as a 4TB until you added another 10TB disk, then one of the 10TBs would be your redundant drive.

If you're adding a lot of data to your NAS I can't help but think you've gone too small with the drives, by the time you've added another 4TB to fill it you've only got a 10TB NAS + the Redundant Drive.
I'm thinking the same to be honest. I'm at the point where I can return the drives as it's within 14 days I'm wondering If I return the 2 x 4tbs and the 1 x 3tb and just install one 10tb for now. My only query would be how do I pull out the drives without losing my existing data? Should I add in a 10tb and then pull the rest of them out or do they need to be done one by one? I'm actually wondering if I essentially start from scratch: remove and return all existing discs, install a 10tb. Would this degrade the pool in any way? I'm not worried about data loss since I have backups of all the data on the NAS.
 
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Sloppy Bob

Distinguished Member
My only query would be how do I pull out the drives without losing my existing data? Should I add in a 10tb and then pull the rest of them out or do they need to be done one by one?

You only have single disk redundancy, so you can't pull 3 drives regardless of the size unless you replace them with 3 drives.

If you want to install a 10TB then you're going to need 2 of them if you're still going with SHR-1, you'll have to start over from scratch as even doing them one by one you'd need to keep one of the 4TB's or you'd be running the NAS in a reduced state unless you replaced it as well.

The cheapest way to buy NAS drives is to purchase the WD Duo which is regularly on sale at Amazon. The 20TB version contains 2x10TB WD Reds and is on sale often for ~£350 so that's ~£175 per drive. If you buy the drives separately they're £275.
However, that offer isn't currently on.
 
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Tomnook80

Active Member
You only have single disk redundancy, so you can't pull 3 drives regardless of the size unless you replace them with 3 drives.

If you want to install a 10TB then you're going to need 2 of them if you're still going with SHR-1, you'll have to start over from scratch as even doing them one by one you'd need to keep one of the 4TB's or you'd be running the NAS in a reduced state unless you replaced it as well.

The cheapest way to buy NAS drives is to purchase the WD Duo which is regularly on sale at Amazon. The 20TB version contains 2x10TB WD Reds and is on sale often for ~£350 so that's ~£175 per drive. If you buy the drives separately they're £275.
However, that offer isn't currently on.
Gotcha. So perhaps as I've 'made my bed' now it's better to stick with what I have and just replace them one by one on future? This is lesson well and truly learnt I reckon!
 

Sloppy Bob

Distinguished Member
If I was you, I'd probably leave it and see how you get on with drive space.

Setup an alert on - Amazon price tracker, Amazon price history charts, price watches, and price drop alerts.
For the drive sizes you want including the WD Duo - Amazon product
You'd need to set one up for the different sizes as it's not always the 20TB that's on sale, personally, I wouldn't go smaller as that 10TB on sale is the best price per TB at the moment.

Then when you get it, remove the drives from the WD, add the first to your NAS, expand the array and when that's done you can remove your 3TB and add the second drive, then rinse and repeat for the others as and when you need to.
 

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