NAS RAID question

[Michael]

I have a Synology 412+ and 4 4 TB WD Rec drives on their way to me. I have not used RAID before on my personal computers. From my reading, RAID 5 seems to be the best choice for the 4 drive system. A balance of redundancy and performance.

Synology seems to have their own Hybrid RAID, but the big advantage cited is the ability to use drives of differing sizes and that is not the case for me in this instance. So the hardware RAiD 5 seems like the best choice.

Any differing opinions on this?

For choosing the NAS, I found that the main choices were build your own with FreeNAS (I have an old WHS machine I did that for), Synology and QNAP. I did not want to mess around with learning FreeNAS and online opinions about QNAP and Synology were pretty balanced. In terms of available additional packages, x86 seemed like the best option. For a pure file server, ARm seemed fine, but with all that storage, I figured why not experiment with the other packages available?

One of the main uses will be the target drive for an iTunes server. No NAS has a clean implementation of Homesharing. WHS that also runs iTunes seems to be one option but I don't want to have to use a tower.

Michael

 

[beginner99]

Personally I would not bother with RAID at all and if you real need redundancy just go with RAID 1.

 

[LurchFrinky]

I would go with RAID 10 if you have 4 drives.

 

[smitbret]

Personally I would not bother with RAID at all and if you real need redundancy just go with RAID 1.

Why would you go with RAID 1 over RAID 5? Seems like it would be a much less efficient use of his HDD space with no real benefit for home use.

 

[Michael]

Why RAID 10 over RAID 5? What would I gain? RAID 5 reduces my usable space from 16 to 12 TB but it give me protection from 1 drive failure. 25% storage hit for more certainty that I do not lose data. What does RAID 10 give me?

Michael

 

[LurchFrinky]

Why RAID 10 over RAID 5? What would I gain? RAID 5 reduces my usable space from 16 to 12 TB but it give me protection from 1 drive failure. 25% storage hit for more certainty that I do not lose data. What does RAID 10 give me?

It's mostly a matter of preference. RAID 10 is higher performance, lower capacity, and can survive 1 or 2 drives failing depending on which drives. You can search the web for which is better and find that it is not so easy a question to answer.

But you are not going to lose data anyway, because you are smart enough to know that RAID != backup and you have a separate backup solution.

 

[Michael]

You are correct about back-up. The PCs in my family will back-up to the NAS. The NAS has an eSATA port and I will back up the key data (not the things I can just download again like iTunes purchases) to an external drive and take the drive to work so if my place burns down (probably more likely than 2 drives failing), I will have a back-up.

I am also looking into Crashplan.

I read a bunch of websites that discussed RIAD 5 vs. 10. From what I can tell, if you are using the disk storage for mail server or database operations, the additional performance is worth the loss of storage to go from 5 to 10. Plus, additional data redundancy. The general recommendation seems to be 10 over 5 if you are editing video or photos on the disks in the NAS. Otherwise, 5 is a better compromise for typical home use which is much more read (streaming) than write and when the normal write operation is backing -up which happens at night while you are sleeping.

I just wanted to make sure I was not missing anything as I have never used RAID before.

Michael

 

[IndyColtsFan]

As long as you're running backups of the important stuff, you can probably use RAID5. Just remember that statistically speaking, RAID5 for volumes with individual spindles above 1 TB isn't a great idea. Here's the explanation:

http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162

If you're using high-end enterprise drives, the error rates are much lower and this wouldn't necessarily apply, but if you're using high-end enterprise drives, you're probably not using RAID5.

Also, to Michael -- I use Crashplan as my cloud backup and like it.

 

[beginner99]

Why would you go with RAID 1 over RAID 5? Seems like it would be a much less efficient use of his HDD space with no real benefit for home use.

Because the parity calculations are expensive and on low-power NAS system troublesome and often when one drive fails another will follow due to the increased stress on the remaining drives and you lose everything.

RAID is for redundancy and that is IMHO not really important for storing your personal music, photos and videos. And for performance it's useless too in a NAS because Gbit ethernet is the limit even for slow green drives.

Rather than wasting time with RAID, use it for a proper backup-plan.

 

[amitkher]

In addition to what IndyColtsFan says, see raid write hole ( https://blogs.oracle.com/bonwick/entry/raid_z). Unless you have redundant power supplies, accident proof household, no power failures, rodents etc. you are vulnerable to the hole. FREENAS solves the problems, both of raid write hole and URE problem posted here earlier.

With synology, your best bet is to use their time backup, using multiple volumes. Versions good, RAID bad.

 

[aigomorla]

raid 5 will give u redudancy on 1 drive while adding the caps on all the drive minus 1 drive. (slowest out of the raids i have listed)

Raid 0 will give u 0 redundancy but give you 100% of all the caps on all the drive as well as give u the fastest performance.

Raid 1 will give the best redudancy by splitting it.. also splitting your storage capacity by half.


As u can see Raid is Fault tollerance...
Go with what u feel is the safest to you, as well as the most space.
Some people dont care of redundancy cuz they do backups on other machines so they raid 0 for storage...

Others raid 5 because they want redudancy and storage capacity.
(i personally use Raid-Z which is sort of like Raid-5)

On my desktops where i do scheduled backups, i use a Raid 0... because i want the raw speed and large storage space...

On my backup servers... i have mirrored Raid 1 to make sure my backups are fault tolerant.

Why RAID 10 over RAID 5? What would I gain? RAID 5 reduces my usable space from 16 to 12 TB but it give me protection from 1 drive failure. 25% storage hit for more certainty that I do not lose data. What does RAID 10 give me?

Michael

This is how i learned my Raid. (if i am wrong someone please correct me)
Raid 10 => 2 x Raid 1 array combined to act as a Raid 0.
Hence Raid 10 => Raid 1 + Raid 0 for Raid 10.

So it would first off require 4 disk, where 2 were mirroed and then the 2 mirror were raided in 0.
This allows 2 disks to fail... one from each Raid1 array b4 ur running around looking for your backups.
This is faster then a Straight R1.... However this is very heavy on overhead... hence why people typically buy 400-1500 dollar controllers to pull these type of raids off.

 

[dstevod]

As long as you're running backups of the important stuff, you can probably use RAID5. Just remember that statistically speaking, RAID5 for volumes with individual spindles above 1 TB isn't a great idea. Here's the explanation:

http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162

Wow - I had no idea about this, although I'm only running 3x1TB.

Potentially scary though!

S

 

[Emulex]

i'd avoid raid-5/6 as any loss of service (hang,crash,reboot unexpected, or loss of power) will require a rescan of all sectors which can take forever and impact (power,heat,performance).

 

[SuPrEIVIE]

I never understood the need to mirror it is a waste of space, just rely on an external safe backup, and use all the drives for storage performance.

 

[Cerb]

I never understood the need to mirror it is a waste of space, just rely on an external safe backup, and use all the drives for storage performance.

While you check your backup and bring your system back online, you've got people twiddling their thumbs, costing you or your boss(es) just as much as if they were getting work done at a normal rate. That is why you use any fault-tolerant RAID. For a home user, it's purely a matter of convenience.

 

[IndyColtsFan]

While you check your backup and bring your system back online, you've got people twiddling their thumbs, costing you or your boss(es) just as much as if they were getting work done at a normal rate. That is why you use any fault-tolerant RAID. For a home user, it's purely a matter of convenience.

This x1000.

Some of you guys aren't looking at RAID correctly. RAID is simply there for fault tolerance and to increase system availability. It may not matter to you if a drive croaks at home and takes out your Plex server -- you'll just get another drive and restore your backup (you guys ARE taking backups, right?). For a business, every second of availability counts and depending on the application, could cost a business thousands of dollars per minute (or more). This is why you use RAID, so if a drive croaks, you're alerted and can replace the dead or dying drive during an off-business-hours maintenance window.

And besides that, even for home users, it is actually making more and more sense due to the low price of drives. I just bought a cheap Synology 4 bay NAS and stuffed it with the el cheapo $150 Seagate 4 TB drives. So for $300, you can have 4 TB of fault-tolerant storage. For $600, you can have an 8 TB RAID10 array.

 

[Kougar]

For home use, just use RAID 5 unless performance is an issue, then RAID 10 might be better.

For true data security, it's pretty cheap to just build a RAID 5 NAS, and then take one or two high capacity drives and store them in a security deposit box someplace. $15 a year for a bank security box with one or two terabyte drives inside is a lot cheaper than multi-Terabyte online backup plans.

Not to mention it's faster to go down the street to the nearest bank and swap out a drive than it is to upload a few terabytes to an online storage vault.

As long as you're running backups of the important stuff, you can probably use RAID5. Just remember that statistically speaking, RAID5 for volumes with individual spindles above 1 TB isn't a great idea. Here's the explanation:

http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162

If you're using high-end enterprise drives, the error rates are much lower and this wouldn't necessarily apply, but if you're using high-end enterprise drives, you're probably not using RAID5.

Also, to Michael -- I use Crashplan as my cloud backup and like it.

Here's a good counter-point article about that http://www.high-rely.com/hr_66/blog/why-raid-5-stops-working-in-2009-not/