Raiding question

[UrbanFreestyle]

Hi all. Ok so i know this could cause some controversy but i'm prepped for that... here is my situation and i hope someone can help me out with a solution.

I currently have my PC Built and it is running fine. The OS is on the m.2 drive direct onto motherboard. The data is stored in a raid 0 of 2x 2tb HDD in the PC.

I own a 4 bay NAS with 4x 2tb HDD and would like to use this as a backup for my PC.

 

Being that it is 4 bay i thought it might be worth raiding those too. NOW,.....

I know that RAID is NOT A BACKUP but the data on the PC will be duplicated onto the NAS (whether jbod or raid so in this case it is.

 

Can anyone recommend the configuration i should put these drives in? The data stored is non-critical (i can deal with downtime) but it is important as it is my media content (semi-pro freelance photographer)

 

I have so far been thinking either just bang it in as a JBOD as it is duplication of my PC or should i raid 6 or 10 or 5 them?

 

[scottyseng]

I say RAID6. You can lose any two drives.

 

RAID10 has better performance for random IO, but I don't think you'll be doing that much for photography storage. Also 50% space hit.

[matt-fr]

What is the brand of the NAS ?

Synology has their own RAID system that work pretty well (SHR).

[UrbanFreestyle]

It's a Buffalo Terrastation

[soulreaper11207]

I would say 5 would be your best bet. 6 has a higher write time due to it handling 2 parity sections and not just one. 

[UrbanFreestyle]

5 it is then  just running config now

[dalekphalm]

5 hours ago, UrbanFreestyle said:

Hi all. Ok so i know this could cause some controversy but i'm prepped for that... here is my situation and i hope someone can help me out with a solution.

I currently have my PC Built and it is running fine. The OS is on the m.2 drive direct onto motherboard. The data is stored in a raid 0 of 2x 2tb HDD in the PC.

I own a 4 bay NAS with 4x 2tb HDD and would like to use this as a backup for my PC.

The 2x 2TB in a RAID0 is kind of a nightmare scenario, but assuming the data is non-critical, and you're backing it up regularly anyway? I can let it slide...

5 hours ago, UrbanFreestyle said:

Being that it is 4 bay i thought it might be worth raiding those too. NOW,.....

I know that RAID is NOT A BACKUP but the data on the PC will be duplicated onto the NAS (whether jbod or raid so in this case it is.

Here's my suggestion, you have a 4 bay NAS, and 4 drives. You have 2 good options:

1. "High protection" = RAID10 the drives. You'd get 4TB effective usable space, and you can lose 2 drives from the array and be fine.

2. "High capacity" = RAID5 the drives. You'd get 6TB effective usable space, and you can sustain a single drive failure.

 

I wouldn't waste your time with RAID6 on a 4-drive array. Your performance will be worse compared to RAID10, for little benefit.

5 hours ago, UrbanFreestyle said:

Can anyone recommend the configuration i should put these drives in? The data stored is non-critical (i can deal with downtime) but it is important as it is my media content (semi-pro freelance photographer)

 

I have so far been thinking either just bang it in as a JBOD as it is duplication of my PC or should i raid 6 or 10 or 5 them?

I'd advise strongly against JBOD or RAID0 on the NAS, since it'll be your backup, and you're already using RAID0 on your primary PC's data drive. In my opinion, RAID5 is the way to go.

 

PS: make sure to configure actual scheduled backups on the main PC, so that the NAS has a history of files, not just a "mirror" of what's currently on your PC. This will ensure you have protection against things like accidental deletion and malware infections.

[Acedia]

5 hours ago, scottyseng said:

I say RAID6. You can lose any two drives.

 

RAID10 has better performance for random IO, but I don't think you'll be doing that much for photography storage. Also 50% space hit.

RAID6 on 4 drives is also a 50% hit...

[scottyseng]

13 minutes ago, Acedia said:

RAID6 on 4 drives is also a 50% hit...

It's around 2/3 space hit. I used to have both a four drive RAID10 and four drive RAID6 array.

 

@UrbanFreestyle

Though I'm thinking of a hardware RAID controller instead of this NAS. RAID5 is probably more ideal for this terastation.

 

I agree with @dalekphalm RAID0 for the boot drive or NAS is a not a great idea. I did it as a boot drive for lolz when I had a prebuilt PC...then one drive died. lol. I had a backup too, but it's not a fun headache to deal with.

[dalekphalm]

1 hour ago, scottyseng said:

It's around 2/3 space hit. I used to have both a four drive RAID10 and four drive RAID6 array.

If you're getting a 2/3 space hit, something isn't right (or you're not factoring in the TB to TiB conversion).

 

RAID6 uses 2 drives worth of capacity for parity. For a 4 drive array, that should be pretty much 50%.

 

Now, in the case of 4x 4TB = 16TB = 14.55TiB

 

8TB (half of the array) = 7.28TiB

 

Now, with that in mind, it's possible a hardware RAID card might be using a tiny amount of storage capacity as overhead, but I can't imagine it would take up 17% of the drive (2/3 - 1/2).

1 hour ago, scottyseng said:

@UrbanFreestyle

Though I'm thinking of a hardware RAID controller instead of this NAS. RAID5 is probably more ideal for this terastation.

 

I agree with @dalekphalm RAID0 for the boot drive or NAS is a not a great idea. I did it as a boot drive for lolz when I had a prebuilt PC...then one drive died. lol. I had a backup too, but it's not a fun headache to deal with.

Agreed - losing a drive to RAID0, even with backups, is annoying at best. Even if you have an Image you can fully restore. Worse if there's no image and you've got to manually restore files.

[scottyseng]

29 minutes ago, dalekphalm said:

If you're getting a 2/3 space hit, something isn't right (or you're not factoring in the TB to TiB conversion)

Ah, sorry,2/3 usable space (Maybe not exactly 2/3 but more than 50% for sure). I forgot the numbers from my old array, but I know the RAID10 array was 50% usable space and the RAID6 array was larger.

[Acedia]

26 minutes ago, scottyseng said:

Ah, sorry,2/3 usable space (Maybe not exactly 2/3 but more than 50% for sure). I forgot the numbers from my old array, but I know the RAID10 array was 50% usable space and the RAID6 array was larger.

You can't argue with simple math.

With RAID10 and 4 disks you write:

A1 | A1 | A2 | A2

B1 | B1 | B2 | B2

So you need double the space per block, hence 50% storage capacity.

 

With RAID6 and 4 disks you write:

A1 | A2 | Ap | Aq

B1 | Bp | B2 | Bq

Or some other distribution of parity blocks, which also results in 50% storage capacity.

[dalekphalm]

57 minutes ago, scottyseng said:

Ah, sorry,2/3 usable space (Maybe not exactly 2/3 but more than 50% for sure). I forgot the numbers from my old array, but I know the RAID10 array was 50% usable space and the RAID6 array was larger.

Beyond 4 disks, RAID6 is larger, as it scales non-linearly.

[leadeater]

The other important point about RAID 10 vs 6, though not applicable if you have used all the HDDs slots, is that RAID 6 can be expanded where RAID 10 cannot. To have an expandable RAID 10 array you have to move away from traditional RAID (hardware and software) to ZFS and Storage Spaces etc.

 

Given the choice between RAID 10 or 6 on a 4 disk array I'd go with RAID 6, just make sure you have active write-back cache then the performance difference is near as much moot point. I'd rather be able to expand if I happen to migrate the disks to a large system than not be able to at all.

[UrbanFreestyle]

So boot drive is a single drive, that is being backed up sepperately. The data on the raid 0 is needed as it is my local photo storage. I have a weekly and monthly backup setup to the NAS which is now raid 5. I think it’s pretty much ok.

[dalekphalm]

5 hours ago, UrbanFreestyle said:

So boot drive is a single drive, that is being backed up sepperately. The data on the raid 0 is needed as it is my local photo storage. I have a weekly and monthly backup setup to the NAS which is now raid 5. I think it’s pretty much ok.

I would probably change your backup schedule for the RAID0 array to daily - assuming you're using incremental backups, the increased capacity requirements will be negligible.

[UrbanFreestyle]

So a quick update, I have got rid of my raid 0 and added a scratch disk for my current photo set that I am working on, the rest will be on one of the hdd in normal formatting