# Opinions on 5-Bay NAS?



## slim142 (Feb 11, 2018)

Looking for a 5-bay NAS.
This is mostly going to be used for data backup and movie storage. No need for 4K (or any crazy) transcoding. Just decent speeds and RAID5 capable + dual Gigabit for teaming.
I will be using WD Reds 8TB for 32TB of total data.

I was looking into the QNAP TS-563, reviews on Newegg kinda scared me away, but it seems pretty popular overall.
Was also looking into the Synology DS-1517+. Great unit but it seems a bit pricey at $700 (but will consider it if worth it).

Is there any unit I should be looking into or anyone would recommend for my situation?


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## repman244 (Feb 11, 2018)

How about a 4-bay or 6-bay NAS and using the drives in RAID 10? Or is storage space critical for you and it's the reason you're choosing RAID 5?


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## slim142 (Feb 11, 2018)

repman244 said:


> How about a 4-bay or 6-bay NAS and using the drives in RAID 10? Or is storage space critical for you and it's the reason you're choosing RAID 5?



Yeah I dont really want to mirror my storage. I'm fine with single parity for safety purposes.
Is there a 4-bay or 6-bay you would particularly recommend? If so, why?


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## Jetster (Feb 11, 2018)

Synology or build your own

I wouldn't put to much thought to Newegg reviews
https://www.smallnetbuilder.com/nas/nas-reviews/32886-qnap-ts563-turbo-nas-reviewed

Just for reference
http://www.zdnet.com/article/raidfail-dont-use-raid-5-on-small-arrays/


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## taz420nj (Feb 12, 2018)

repman244 said:


> How about a 4-bay or 6-bay NAS and using the drives in RAID 10? Or is storage space critical for you and it's the reason you're choosing RAID 5?



Basically because for NAS media storage RAID 10 is a major waste of money.  You won't realize any of the speed of 0, and a 50% overhead loss when you're talking about $1300 worth of drives is kind of insane.


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## repman244 (Feb 12, 2018)

taz420nj said:


> Basically because for NAS media storage RAID 10 is a major waste of money.  You won't realize any of the speed of 0, and a 50% overhead loss when you're talking about $1300 worth of drives is kind of insane.



It is insane but it's a much safer option than 5. Rebuild times can be huge with the desired capacity, and read errors during rebuild comes into play.
If the OP is fine with lower security but higher storage space then RAID 5 it is.


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## Disparia (Feb 12, 2018)

Just an FYI, I'm at 5TB of 16TB total capacity and 2.26TB of that is 1,200 movies. Granted, many are DVD rips recoded with H.264, but there's a good deal of BD too, also at H.264.

Perhaps look at the *4*-bay models? There are so many more to chose from. Spend less on it and only 4 drives, still have a respectable 24TB. Many support an expansion unit that'll attach to the main unit if you're on pace to fill that in the future.


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## arroyo (Feb 12, 2018)

I have "kind a cheap" 5 bay NAS:
4 bay Asustor AS6204T + one HDD connected thru esata in Scythe Quiet Drive glued on top of NAS.


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## taz420nj (Feb 12, 2018)

repman244 said:


> It is insane *but it's a much safer option than 5*. Rebuild times can be huge with the desired capacity, and read errors during rebuild comes into play.
> If the OP is fine with lower security but higher storage space then RAID 5 it is.



Except it's really not.  RAID 10 can only tolerate one mirror failure on either side of the stripe. If both mirrors on the same side fail, the array is toast anyway. RAID6 is "much safer" than both 5 and 10, and still only has a 40% overhead in a 5-drive array.  Make it a 6 drive array and the overhead loss drops to 33%. As far as rebuilds go, this is where it is better to build your own NAS with a good dedicated RAID card versus using a weak SoC based prefab, because the custom box will always rebuild faster.  Also the choice of drives comes into play..    I went with HGST Ultrastars in my arrays because (aside from years of experience on their longevity) they are enterprise rated for 10^15 BER (one URE per 125TB read). The likelihood of having a failed drive plus two UREs at the same time are incredibly remote (but admittedly not zero).  WD Reds are still consumer drives with 10^14 BER (one URE per 12.5TB read) but remember that is an average not a promise.  RAID6 is still preferable to 10 with them because again the chance of having a failed drive plus two UREs is slim enough to justify the capacity gain re: less overhead.


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## repman244 (Feb 13, 2018)

taz420nj said:


> Except it's really not.  RAID 10 can only tolerate one mirror failure on either side of the stripe. If both mirrors on the same side fail, the array is toast anyway. RAID6 is "much safer" than both 5 and 10, and still only has a 40% overhead in a 5-drive array.  Make it a 6 drive array and the overhead loss drops to 33%. As far as rebuilds go, this is where it is better to build your own NAS with a good dedicated RAID card versus using a weak SoC based prefab, because the custom box will always rebuild faster.  Also the choice of drives comes into play..    I went with HGST Ultrastars in my arrays because (aside from years of experience on their longevity) they are enterprise rated for 10^15 BER (one URE per 125TB read). The likelihood of having a failed drive plus two UREs at the same time are incredibly remote (but admittedly not zero).  WD Reds are still consumer drives with 10^14 BER (one URE per 12.5TB read) but remember that is an average not a promise.  RAID6 is still preferable to 10 with them because again the chance of having a failed drive plus two UREs is slim enough to justify the capacity gain re: less overhead.



RAID 5 tolerates one fail as well but the rebuild compared to RAID 10 is much more demanding on the drives that's why 10 is safer.
RAID 6 is not always considered as a safer option, yes it does allow any 2 drives to fail but again compared to 10 it's more demanding during rebuild. It's not as simple as only looking at the number of drives that can fail.

I've seen many switching from RAID 6 to 10 for this exact reason...however that is a subject not related to the thread and it depends on what you expect from your RAID.


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## taz420nj (Feb 13, 2018)

repman244 said:


> RAID 5 tolerates one fail as well but the rebuild compared to RAID 10 is much more demanding on the drives that's why 10 is safer.
> RAID 6 is not always considered as a safer option, yes it does allow any 2 drives to fail but again compared to 10 it's more demanding during rebuild. It's not as simple as only looking at the number of drives that can fail.



I would NEVER consider 10 for anything other than a production environment where the speed of 0 is required (since I would NEVER use 0 without 1) - certainly not a large scale storage system, and most certainly not one that holds non-valuable, easily replaceable material such as media rips.    Like I said, you will NEVER see the speed benefits of 0 on a NAS, so there's absolutely no point in using it or any level that uses it.  As far as a rebuild being more demanding, I don't really think that's the case.  You still have to read every bit from the mirror just like you have to read every bit from the remaining drives in a RAID 6.  The speed at wich that happens depends solely on the XOR engine.  A better RPU does the parity calculations faster - which spells the difference between a rebuild taking 6 hours or 5 days.  Yes there is a n-times chance of another drive failure in that time (n= # of remaining drives), and then a 10^14 or 10^15 chance of a URE in a RAID 6.  But that's still less of a chance than the other mirror failing and blowing the whole array.



> I've seen many switching from RAID 6 to 10 for this exact reason...however that is a subject not related to the thread and it depends on what you expect from your RAID.



Sorry but I don't believe that for a second.  Once again, there is absolutely no point to using 10 in these situations, much less any that could be any sort of "advantage" over 6..  Might as well just use 1 and completely avoid the risks of striping.


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## slim142 (Feb 20, 2018)

I truly enjoyed the reading. Guys, this is for a home-server purposes. I will be storing movies and a backup of all of my data. For company purposes, I would probably consider more options, but for now, RAID 5 will do.

I have decided to go for Synology. I will eat the extra cost, but hopefully it works as expected.


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