Synology NAS / RAID configuration Advice.

[Vectraat]

So I bought a Synology DS918+ recently and before I set it up I have some questions that I figured the folks around here may be able to answer.

 

1.) According to a video I watched, once you set your RAID type if you want to change it later on, all of the data on your discs will be erased? Does this apply to Synologies SHR-1 as well--if I were to switch SHR-1 to another RAID type?

 

2.) I notice that the default RAID type for Synology NAS is SHR-1 and it seems to be very similar to RAID 5. They both offer a 1x HDD redundancy but RAID 5 requires 3+ drives while SHR-1 will work with only 1. Also, SHR-1 seems to be better at calculating HDD space. I'm not sure if there's a difference in read/write between the two RAID configurations? Is there a reason to go with RAID 5 over SHR-1?

 

3.) Using the Synology RAID type tool, I see: Space "Unused" "Used for protection" "Available Space" I assume "Unused" means that you can never access that space?

 

4.) Since the DS918+ can use a SATA expansion port to provide 5 more drive bays - if I use the second bay will I be able to set two different Single Volume RAIDS? One for the main NAS and a different one for the expansion unit? Or am I stuck using the RAID I set for the main NAS on the expansion unit as well? I'd only need to use "Multiple Volumes on RAID" if I wanted to configure multiple RAIDS on the main 4 HDD slots? So for example - a combination of SHR-1 and RAID 0 would be possible?

 

5.) I'm not entirely sure what RAID type I should go with. I should mention that I currently only have 1x 10 TB drive and I plan to add more 10 TB drives eventually. I want redundancy but I don't want redundancy. Maybe you guys can come up with a better solution that I haven't considered. I don't want RAID 0 because if one drive dies they all die. The maximum I want is 1x HDD redundancy. But right now I have everything backed up to external drives so I'm fine with having no redundancy I just don't want all my drives to die if one dies. Is there a RAID type that will offer me no redundancy but won't nuke all of my other drives when one fails? Can something like JBOD do that?

 

6.) Ok, I don't really get the networking aspect of the NAS as my understanding of networking is poor. I have a dynamic IP address. From what I'm aware, most ISPs offer dynamic only. The NAS looks incredibly easy to setup if you have a static IP, but with a dynamic IP I assume I need to setup port forwarding and acquire a static IP? I use a VPN as well and I'm working on port forwarding for that--I think there's a bug with it right now--so this sounds like it could get complicated. Should I try to get a static IP from my ISP or just try to set it up with dynamic? I'd like to be able to access my NAS away from home.

 

Thanks for reading.

[NelizMastr]

1 hour ago, Vectraat said:

So I bought a Synology DS918+ recently and before I set it up I have some questions that I figured the folks around here may be able to answer.

 

1.) According to a video I watched, once you set your RAID type if you want to change it later on, all of the data on your discs will be erased? Does this apply to Synologies SHR-1 as well--if I were to switch SHR-1 to another RAID type?

SHR will adapt to the amount of drives you put in. It's Synology Hybrid RAID. Changing RAID modes, so foregoing SHR entirely and going for a RAID0/1/5/10 and then wanting to switch, will always delete all data in the array, yes. Pick a RAID level and stick with it saves a lot of headaches. \

 

1 hour ago, Vectraat said:

2.) I notice that the default RAID type for Synology NAS is SHR-1 and it seems to be very similar to RAID 5. They both offer a 1x HDD redundancy but RAID 5 requires 3+ drives while SHR-1 will work with only 1. Also, SHR-1 seems to be better at calculating HDD space. I'm not sure if there's a difference in read/write between the two RAID configurations? Is there a reason to go with RAID 5 over SHR-1?

Again, it's hybrid RAID. When you only have one drive, SHR will run in RAID0 mode, without any protection. With two drives, RAID1, with 3 and more RAID5.  Not 100% on what more drives will default to. I'd imagine it switches to RAID6 on the larger models (8+ bays). Calculating disk space is the same across all RAID levels. Some RAID levels simply have less capacity than others, in trade for better protection or better performance. RAID10 has 50% capacity but performs twice as well as a RAID1 or 5 at writing data for instance. RAID5 has the highest capacity but is rather slow at writing.

 

1 hour ago, Vectraat said:

3.) Using the Synology RAID type tool, I see: Space "Unused" "Used for protection" "Available Space" I assume "Unused" means that you can never access that space?

 

Correct. There's always a couple of megabytes (a few hundred typically) per drive that you'll never be able to use. You also lose some from the calculation to binary, as drive space is advertised in decimal (1TB being 1000GB in decimal, but a binary TB (TiB) is 1024GB).

 

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4.) Since the DS918+ can use a SATA expansion port to provide 5 more drive bays - if I use the second bay will I be able to set two different Single Volume RAIDS? One for the main NAS and a different one for the expansion unit? Or am I stuck using the RAID I set for the main NAS on the expansion unit as well? I'd only need to use "Multiple Volumes on RAID" if I wanted to configure multiple RAIDS on the main 4 HDD slots? So for example - a combination of SHR-1 and RAID 0 would be possible?

Can't answer this one, sorry

 

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5.) I'm not entirely sure what RAID type I should go with. I should mention that I currently only have 1x 10 TB drive and I plan to add more 10 TB drives eventually. I want redundancy but I don't want redundancy. Maybe you guys can come up with a better solution that I haven't considered. I don't want RAID 0 because if one drive dies they all die. The maximum I want is 1x HDD redundancy. But right now I have everything backed up to external drives so I'm fine with having no redundancy I just don't want all my drives to die if one dies. Is there a RAID type that will offer me no redundancy but won't nuke all of my other drives when one fails? Can something like JBOD do that?

JBOD is just a bunch of disks. You should be able to use the drives independently. One drive death will mean the death of all data on that drive, though.

 

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6.) Ok, I don't really get the networking aspect of the NAS as my understanding of networking is poor. I have a dynamic IP address. From what I'm aware, most ISPs offer dynamic only. The NAS looks incredibly easy to setup if you have a static IP, but with a dynamic IP I assume I need to setup port forwarding and acquire a static IP? I use a VPN as well and I'm working on port forwarding for that--I think there's a bug with it right now--so this sounds like it could get complicated. Should I try to get a static IP from my ISP or just try to set it up with dynamic? I'd like to be able to access my NAS away from home.

Your NAS is on your internal network. This means your ISP isn't part of the equation. It's not directly connected to the internet, but goes through your modem/router to get there. Dynamic IP in this situation means DHCP, your router provides an IP to your NAS that may change if it stays turned off for a set amount of time. Choose an unoccupied IP address in your network to make it static. Typically, 192.168.1.5 (if your network is 192.168.1.x) is a safe bet. 

You can access the NAS without port forwarding by using Quickconnect. You'll have a custom URL for your NAS to access the web interface. You won't be able to map the shares to your PC remotely, but you can at least browse and download/upload files over the internet.

[Radium_Angel]

@Vectraat

 

(1) You cannot change RAID types without wiping your drives. Pick one (RAID 5 works well) and stick with it.

(3) "Unused" I assume means space for your data.

(4) I've never seen a NAS that can do different RAID types, but it's possible I suppose, you'd have to read the manual for clarification

(5) If you only have 1 drive currently, then you can't do RAID. Unless you pick something dumb like RAID 0, you won't lose all your data if one of the drives dies. I assume you've read and researched the different RAID types? If not, you should....

(6) You set a static IP from your router, which gets the dynamic IP from your ISP. The NAS has to have a static IP so your other systems can find it.

[Vectraat]

1 hour ago, Radium_Angel said:

@Vectraat

 

(5) If you only have 1 drive currently, then you can't do RAID. Unless you pick something dumb like RAID 0, you won't lose all your data if one of the drives dies. I assume you've read and researched the different RAID types? If not, you should....

https://en.wikipedia.org/wiki/Standard_RAID_levels

"Since RAID 0 provides no fault tolerance or redundancy, the failure of one drive will cause the entire array to fail; as a result of having data striped across all disks, the failure will result in total data loss."

[Pixel5]

the Unused space is not accessible and this only happens if you combine a certain number and sizes of drives that make it impossible to be redundant while using the full available space.

 

changing the raid type is only possible when going from SHR 1 to SHR 2 but i guess thats not something you wanna do.

 

You can span a volume across the regular drive or the expansion unit or create multiple volumes with different raid types as you like.

Its actually highly encouraged to create a separate volume on the expansion unit because if the units disconnects and its only one volume you will have a degraded array immediately.

 

if you want to start with one 10TB drive thats fine as long as you have a full backup available, set this drive up as SHR 1 and you can easily add more drives as your storage needs increase.

[Radium_Angel]

2 hours ago, Vectraat said:

https://en.wikipedia.org/wiki/Standard_RAID_levels

"Since RAID 0 provides no fault tolerance or redundancy, the failure of one drive will cause the entire array to fail; as a result of having data striped across all disks, the failure will result in total data loss."

Sigh, here we go again.

 

"RAID" 0 isn't RAID, because there is no redundancy.

It's a BS spec.

[Vectraat]

On 6/13/2018 at 2:47 AM, NelizMastr said:

JBOD is just a bunch of disks. You should be able to use the drives independently. One drive death will mean the death of all data on that drive, though.

From reading the Synology website I see: 

"JBOD*: Combines at least two hard disks to create a storage pool. JBOD storage pools do not offer data redundancy. The available capacity of a JBOD storage pool equals the total capacity of all disks included in the storage pool. JBOD supports combining hard disks of varying sizes."

 

So I'm interpreting this to mean that I need at least 2x HDDs to use JBOD and if one of them dies, they both die. And if I have 4x HDDs, then there will be two pairs. If 1x HDD in each pair dies then all of my storage is dead. 

[Vectraat]

On 6/13/2018 at 5:34 AM, Pixel5 said:

the Unused space is not accessible and this only happens if you combine a certain number and sizes of drives that make it impossible to be redundant while using the full available space.

 

changing the raid type is only possible when going from SHR 1 to SHR 2 but i guess thats not something you wanna do.

 

You can span a volume across the regular drive or the expansion unit or create multiple volumes with different raid types as you like.

Its actually highly encouraged to create a separate volume on the expansion unit because if the units disconnects and its only one volume you will have a degraded array immediately.

 

if you want to start with one 10TB drive thats fine as long as you have a full backup available, set this drive up as SHR 1 and you can easily add more drives as your storage needs increase.

Ok, that's great to know - that I can set a different RAID array for the 5 port expansion unit. Not even Synology customer service knew how to answer that question lol!

Well, as I mentioned, I was looking at JBOD, but according to Synologies website, JBOD combines at least two HDDs to create a single storage pool. Since I only have 1x HDD I can't use it and even if I could, I don't like that between a total of 4 HDDs if 1x HDD fails in each storage pool, all of my data is gone. So I'm forced to use SHR-1, which isn't something that I wanted to use because I have everything backed up already and the next $400 I spent on a HDD will be used for redundancy that I don't need. Although, else where in a Synology document it says I can use JBOD with 1x HDD, so now I'm confused. >_> 

RAID 0 is a no-no and it requires 2x HDDs anyway. 

"Basic" only requires 1x HDD though. "A Basic volume is created with one hard drive as an independent unit. When creating a Basic volume, you can select only one hard drive at a time."

So..... I could use 4x HDDs on Basic? No redundancy? I'm not sure as it doesn't say anything else. 

Maybe I'm retarded about this kinda stuff, but it seems really difficult to find a precise explanation of how various RAID types work in practical terms - even Synologies own documentation is incomplete and lacking in detail. 

[Pixel5]

im not sure its possible to run a volume with multiple HDD and no redundancy.

 

thats kinds of one of the main purposes of a NAS today, redundancy may not replace a backup but it gives you some extra security because lets be honest the most often failure that causes data loss is probably a HDD failure whiuch i sadly had happen to me before i had a NAS and lost 1.5TB of data, luckily some of this backed up somewhere else.

[Vectraat]

16 hours ago, Pixel5 said:

im not sure its possible to run a volume with multiple HDD and no redundancy.

 

thats kinds of one of the main purposes of a NAS today, redundancy may not replace a backup but it gives you some extra security because lets be honest the most often failure that causes data loss is probably a HDD failure whiuch i sadly had happen to me before i had a NAS and lost 1.5TB of data, luckily some of this backed up somewhere else.

I thought the point of redundancy was so that you could recover what was lost? If you're mirroring a HDD and one of those HDDs dies, you pop in another HDD to recover the data. 

Say you're using SHR-1 or RAID 5 - Using 4x HDDs and one of them dies, don't you just pop in a new HDD and all of the data on that failed HDD is now recovered? 

Though, I would wonder how 1x HDD redundancy can essentially keep track of all the data on the other 3 HDDs and create a restore of a failed HDD. 

[Pixel5]

yes it works exactly like you said, if a disk fails you pop in a new one thats the same or greater size and it will rebuild all the files the old HDD had.

 

my example was that i had no redundancy back then and therefore lost all data with a single HDD failure.

Personally i am running a 918+ with a 3TB and two 8TB HDD´s, that currently gives me about 11TB usable space, if i pop in another 8TB drive ill instantly have 19TB available.

[NelizMastr]

On 6/17/2018 at 12:17 AM, Vectraat said:

Say you're using SHR-1 or RAID 5 - Using 4x HDDs and one of them dies, don't you just pop in a new HDD and all of the data on that failed HDD is now recovered? 

Though, I would wonder how 1x HDD redundancy can essentially keep track of all the data on the other 3 HDDs and create a restore of a failed HDD. 

Yep, works like that. RAID5 volumes are quite strenuous on the disks when they have to rebuild, though, so chances are a 2nd drive will kick the bucket. This is why RAID6 is often considered a safer bet, as you also have a redundant parity disk. This parity disk keeps track of the data stored on all disks. You will lose 2 drives in total in terms of capacity, though.

[dalekphalm]

On 6/16/2018 at 6:17 PM, Vectraat said:

I thought the point of redundancy was so that you could recover what was lost? If you're mirroring a HDD and one of those HDDs dies, you pop in another HDD to recover the data. 

Say you're using SHR-1 or RAID 5 - Using 4x HDDs and one of them dies, don't you just pop in a new HDD and all of the data on that failed HDD is now recovered? 

Though, I would wonder how 1x HDD redundancy can essentially keep track of all the data on the other 3 HDDs and create a restore of a failed HDD. 

Keep in mind that "RAID" systems only protect against hardware failure. Eg: A HDD dies, you pop in a replacement.

 

It will not protect against accidental deletion, virus infection, crypto/ransomware, etc.

 

File Versioning can add some protection to RAID, but just make sure that anything you cannot afford to lose is backed up to a totally separate drive.

[Vectraat]

On 6/17/2018 at 11:33 PM, NelizMastr said:

Yep, works like that. RAID5 volumes are quite strenuous on the disks when they have to rebuild, though, so chances are a 2nd drive will kick the bucket. This is why RAID6 is often considered a safer bet, as you also have a redundant parity disk. This parity disk keeps track of the data stored on all disks. You will lose 2 drives in total in terms of capacity, though.

Man, that's so tough giving up that 2nd HDD when you only have a 4 Bay NAS though.

"You also have a redundant parity disk" Isn't redundant/parity basically just the same thing. 1x on RAID 5 and 2x on RAID 6. 

What do you think is better: SHR-1 or RAID 5? (Yeah, I know they're very similar). The performance/redundancy is the same though? 

1.) Are these doable strategies in terms of RAID migration? 

a.) BASIC RAID (2x disks, no redundancy/parity) --> Add a third disk --> migrate to RAID 5 for striping & parity.

b.) BASIC (1x disk) --> Add a second disk --> RAID 1 (mirrored) --> RAID 5 (3rd disk For striping/parity).

c.) Is it easy to migrate to different RAID configurations? And I won't lose data when migrating? 

2.) JBOD has no migration? Is there a reason to go with JBOD over BASIC? Seems like BASIC is a lot more flexible.