Multiple HDDs and single big volume TS-431+

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Delgon
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Multiple HDDs and single big volume TS-431+

Post by Delgon » Sat Sep 14, 2019 7:57 am

I currently have 2x8TB drives + one new (and 1 3TB spare). I add new drives as I need more space. Till now I just created a single static volume for both of them so I have 2 network discs. What I wanna change is make that I have just one network "Drive" that will have all that storage so in my case overall 3x8TB. As I do not have a way to move current 16TB and create any kind of free space on those drives I just thought that maybe Thick or Thin volumes would do a trick. Right now I know that I have 0 redundancy so do not worry about it. If one drive fails, I can still access data on the other one just fine and even if I had 4 of them it would still hold true.

So I tried to create a storage pool with one 8TB with one Thick or Thin volume as a whole, move data from one drive to this one making the static volume empty so in that way, I would be able to remove it and add it to the storage pool and expand volume. The same with last drive so I would have one big 24TB volume.
I'm not sure how this kind of storage pool and big volume would behave if one of the drives failed. I tried to "simulate" it by creating one storage pool with the new 8TB drive and one 3TB spare. Pushed some data and removed one drive to simulate one of the drives fail. Unfortunately, I was not able to restore or get any data left even if the data was one the 8TB drive (I know as I pushed data on the volume when it was the only one in the pool) or even get the pool to work again, I tried using Thick and Thin volumes. The pool always gave "Error" message, even when I put the drive back and clicked "restore", the pool looked fine as both drives were "good" but the pool still gave "Error" and Volume changed to "unmounted". I was not able to get any access to data that should still be there. Wanted to do some research and testing before I make all my data that way. I do not wanna be in the situation where I lose one drive but lose 3 or more drives worth of data.

Any idea how I can achieve that or am I stuck with making every drive a static volume. and just live with 1 network drive for every HDD in the NAS?

P3R
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Re: Multiple HDDs and single big volume TS-431+

Post by P3R » Sun Sep 15, 2019 7:43 am

Delgon wrote:
Sat Sep 14, 2019 7:57 am
If one drive fails, I can still access data on the other one just fine and even if I had 4 of them it would still hold true.
If the disk failing is the "system" (usually the first installed) disk fail, it will probably cause enough problem for the NAS to become completely unavailable.
I tried to "simulate" it by creating one storage pool with the new 8TB drive and one 3TB spare. Pushed some data and removed one drive to simulate one of the drives fail. Unfortunately, I was not able to restore or get any data left even if the data was one the 8TB drive (I know as I pushed data on the volume when it was the only one in the pool) or even get the pool to work again, I tried using Thick and Thin volumes.
That a storage pool fail completely when ANY of the underlying disk(s) or RAID(s) fail is expected.
Any idea how I can achieve that or am I stuck with making every drive a static volume. and just live with 1 network drive for every HDD in the NAS?
If you don't want to make your life easier by using RAID 1 or higher, that's the best you can do.
RAID have never ever been a replacement for backups. Without backups on a different system (preferably placed at another site), you will eventually lose data!

A non-RAID configuration (including RAID 0, which isn't really RAID) with a backup on a separate media protects your data far better than any RAID-volume without backup.

All data storage consists of both the primary storage and the backups. It's your money and your data, spend the storage budget wisely or pay with your data!

Delgon
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Re: Multiple HDDs and single big volume TS-431+

Post by Delgon » Mon Sep 16, 2019 12:44 am

So assigning multiple drives into one pool is kind of a bad idea as yes, it will allow me to make one volume, but you lose all data even if only one of the drives fail. In that case I do not see any scenarion where you would want to use multiple drives in one pool, kinda useless.
So myu only option is to do as I was doing all the time, just use every drive as separate pool with one single static volume. Kind of a bummer.

To make is a raid right now (I have 2 full 8tb drives) I would need 4 more to make 4 disc Raid 5. (2 to copy all data to, for example to PC and other 2 + 2 in nas to create RAID 5) Do not wanna spend that much money and in the end have 2 discs that I would not know what to do with, waste of money.

P3R
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Re: Multiple HDDs and single big volume TS-431+

Post by P3R » Mon Sep 16, 2019 3:31 am

Delgon wrote:
Mon Sep 16, 2019 12:44 am
So assigning multiple drives into one pool is kind of a bad idea as yes, it will allow me to make one volume, but you lose all data even if only one of the drives fail.
Yes.
In that case I do not see any scenarion where you would want to use multiple drives in one pool, kinda useless.
It can be used to make a quick and dirty storage where you need the ability to expand with additional disks later. But the real advantage and much more used scenario for this feature would be to concatenate multiple RAIDs together. Let's assume that someone have an 8-bay chassis with 4*3 TB in RAID 5 and need to expand it. This person have trouble finding 3 TB disks but get a great deal on 4*6 TB disks. It would now be possible to use those two RAID 5s together as a single volume. Reliability would still be decent with disk redundancy in both RAID 5s.
So myu only option is to do as I was doing all the time, just use every drive as separate pool with one single static volume.
No it isn't. You could:
  1. Use the two new disks to make an external backup of all data.
  2. Reinitialize the NAS and this time set it up with RAID 1.
  3. Restore all data from backup disk A to the NAS.
  4. Put that same backup disk A into the NAS and use it to migrate the RAID 1 to a 3-disk RAID 5.
  5. Restore all data from backup disk B to the NAS.
  6. Put that same backup disk B into the NAS and use it to expand the RAID 5 to a 4-disk RAID 5.
Do not wanna spend that much money and in the end have 2 discs that I would not know what to do with, waste of money.
They would be great to have as an external backup. Even when using RAID, you will most likely eventually lose data if you don't have a backup on a separate system.
RAID have never ever been a replacement for backups. Without backups on a different system (preferably placed at another site), you will eventually lose data!

A non-RAID configuration (including RAID 0, which isn't really RAID) with a backup on a separate media protects your data far better than any RAID-volume without backup.

All data storage consists of both the primary storage and the backups. It's your money and your data, spend the storage budget wisely or pay with your data!

Delgon
Starting out
Posts: 10
Joined: Fri Sep 22, 2017 1:15 am

Re: Multiple HDDs and single big volume TS-431+

Post by Delgon » Mon Sep 16, 2019 10:18 pm

Thanks man for all the answers :)

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