[SOLVED] RAID for Home Based NAS

CodeHardForTheWare

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Hi all,

Apologies if this is an over done question, but I figured that asking would get me the best info.
I have a Seagate 4-bay NAS, currently it is running in JBOD with a 1tb, 4tb, 4tb and 2tb. Totaling
to 11tb of space. I recently bought a 6tb and a 3tb HDD that I want to replace the 1 and 2tb hdds with.
This would increase my total capacity to 18tb.

My question is the following, which RAID would be best suited for a set up that allows some redundancy
improved performance. I have read that RAID 5 is the best way to go, however most examples deal with
having HDDs of the same size and taking up 25% of the total storage for redundancy. In my case, would that
still be the case? Would I be surrendering +/-4.5tb to redundancy?

Again apologies if this is a tired question but this forum assisted me greatly with a networking issue I was having
so it's my go to for queries!!

TIA
 
Solution
With that combination of drives, no RAID will work correctly.
The drives need to be the same size.

"Would I be surrendering +/-4.5tb to redundancy? "
Far worse.

3TB+4TB+4TB+6TB + RAID 5 = 9TB RAID array.
4x the size of the smallest, minus the size of 1x the smallest.


"allows some redundancy improved performance "
The RAID 5 is for physical drive redundancy, not data redundancy. 1 drive can die and the RAID will continue to work until you can schedule downtime to replace it.

"improved performance "
Not really. Since you're connecting to this over a standard gigabit LAN, you'd not see any difference over your JBOD, or even individual drives.

Connecting to my QNAP, I cannot see any difference when writing from an SSD in the PC to...

USAFRet

Titan
Moderator
With that combination of drives, no RAID will work correctly.
The drives need to be the same size.

"Would I be surrendering +/-4.5tb to redundancy? "
Far worse.

3TB+4TB+4TB+6TB + RAID 5 = 9TB RAID array.
4x the size of the smallest, minus the size of 1x the smallest.


"allows some redundancy improved performance "
The RAID 5 is for physical drive redundancy, not data redundancy. 1 drive can die and the RAID will continue to work until you can schedule downtime to replace it.

"improved performance "
Not really. Since you're connecting to this over a standard gigabit LAN, you'd not see any difference over your JBOD, or even individual drives.

Connecting to my QNAP, I cannot see any difference when writing from an SSD in the PC to either an SSD or HDD in the QNAP.
The LAN is the choke point.
 
Solution

CodeHardForTheWare

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Dec 9, 2011
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With that combination of drives, no RAID will work correctly.
The drives need to be the same size.

"Would I be surrendering +/-4.5tb to redundancy? "
Far worse.

3TB+4TB+4TB+6TB + RAID 5 = 9TB RAID array.
4x the size of the smallest, minus the size of 1x the smallest.


"allows some redundancy improved performance "
The RAID 5 is for physical drive redundancy, not data redundancy. 1 drive can die and the RAID will continue to work until you can schedule downtime to replace it.

"improved performance "
Not really. Since you're connecting to this over a standard gigabit LAN, you'd not see any difference over your JBOD, or even individual drives.

Connecting to my QNAP, I cannot see any difference when writing from an SSD in the PC to either an SSD or HDD in the QNAP.
The LAN is the choke point.

Thanks you for the feedback! Do you reckon that I stick to JBOD until I can get identical drives to get a proper hardware setup for a RAID array. I will most likely try and get more 6tb HDDs over the next couple of months to get there.
TIA
 

USAFRet

Titan
Moderator
Thanks you for the feedback! Do you reckon that I stick to JBOD until I can get identical drives to get a proper hardware setup for a RAID array. I will most likely try and get more 6tb HDDs over the next couple of months to get there.
TIA
Even with equal size drives, I would STILL stick with the JBOD.
RAID 5 gives little real benefit.

And with larger size drives (over 4TB), the RAID 5 is contraindicated.
The rebuild time is just too long. On the order of 1.5hour per TB of consumed space.

So...given 4 identical 6TB drives.
18TB viable space.

Lets say you have 10TB data in this array
1 of the 4 drives dies.
Replace it.
The array needs to be rebuilt....this will take ~15 hours, solid hammering on all 4 drives.
One of the originals may also die in this process, rendering all data gone.


RAID is way overhyped as any data protection mechanism.


Whichever way you go, you absolutely need a full 100% backup of all data, and know how to recover.
 

CodeHardForTheWare

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What is the exact usage of the data on your NAS? I only recommend RAID for a few very specific purposes; for most consumers, JBOD, Unraid, or a traditional, timed backup with delta copying is a far better idea than any RAID.

Just movies that I have ripped from my blu-ray collection from streaming. The big reason why I went for a NAS was to not have tons of hard-drive enclosures all over the place. It is starting to look like JBOD is the way to go for me.
BTW, what is Unraid?
 

USAFRet

Titan
Moderator
Just movies that I have ripped from my blu-ray collection from streaming. The big reason why I went for a NAS was to not have tons of hard-drive enclosures all over the place. It is starting to look like JBOD is the way to go for me.
BTW, what is Unraid?
Having the NAS for that use is just fine.
But you're attributing too much capability to what RAID is and does. As OFTEN happens.

UnRaid
 

CodeHardForTheWare

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Even with equal size drives, I would STILL stick with the JBOD.
RAID 5 gives little real benefit.

And with larger size drives (over 4TB), the RAID 5 is contraindicated.
The rebuild time is just too long. On the order of 1.5hour per TB of consumed space.

So...given 4 identical 6TB drives.
18TB viable space.

Lets say you have 10TB data in this array
1 of the 4 drives dies.
Replace it.
The array needs to be rebuilt....this will take ~15 hours, solid hammering on all 4 drives.
One of the originals may also die in this process, rendering all data gone.


RAID is way overhyped as any data protection mechanism.


Whichever way you go, you absolutely need a full 100% backup of all data, and know how to recover.

I see!! Thanks for teaching me about this. RAID is made out to be such an important thing. I guess, as you said, that it's for very specific cases.....
Now, is there ANY way for me to replace my 1tb and 2 tb drives with the 6tb and 3 tb drives?
I am under the impression that I will have to take EVERYTHING of my current volume, replace the drives, setup the new volume and then copy everything back.
Is that really my only option?
 

USAFRet

Titan
Moderator
I see!! Thanks for teaching me about this. RAID is made out to be such an important thing. I guess, as you said, that it's for very specific cases.....
Now, is there ANY way for me to replace my 1tb and 2 tb drives with the 6tb and 3 tb drives?
I am under the impression that I will have to take EVERYTHING of my current volume, replace the drives, setup the new volume and then copy everything back.
Is that really my only option?
What specifically happens when you pull out the 1TB drive?