2.5 vs 3.5" drives for home

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TLN

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Feb 26, 2016
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Hi all.
Gotta choose new drives for home. Looking at 10+TB in RAID6 (RAID Z2) pool. Will be happy to get more, but not less then that. Have LSI3008 passed through to VM for that.

I see that some people recommended 2.5" drives: cheaper, can have more drives in same space. I guess they run cooler also. Or I can go with bigger 3.5" drives. It will be pretty packed workstation then, but hopefully I can cool em down.
I can fit only 6x.3.5" drives. Or I can stick to 2.5" drives: easier to cool, leaves me more space in a case. Easier to work with. and so on.
Another option: is 2-3 big 3.5" drives. 10Tb for example. In RAID1: That way I don't have to deal with RAIDZ or anything like that.

What would be your choice?
 

funkywizard

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I would probably do 6x 3tb hitachi ultrastars. In raid 6 will be 12tb capacity. Last I checked the drives are $60 on ebay, and built like tanks. If you needed more space, 6tb hitachi nas drives are good options.
 

TLN

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Feb 26, 2016
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Depends on budget, speed and resilience requirements:)
Can we say that 2.5" are as reliable as 3.5"?
No need in super-fast storage, but I expect a nice bump in speed compared to two toshibas tht I use.

I would probably do 6x 3tb hitachi ultrastars. In raid 6 will be 12tb capacity. Last I checked the drives are $60 on ebay, and built like tanks. If you needed more space, 6tb hitachi nas drives are good options.
2.5" or 3.5"
 

funkywizard

mmm.... bandwidth.
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I've looked for large 7200rpm 2.5" drives -- not sure if any exist. The 2.5" drives top out at really small sizes, and nearly all of them are 5400rpm or slower. What you gain in per-drive power savings you lose in needing so many more drives.

The hitachi drives have a ridiculously low failure rate. Check out the backblaze reliability stats, especially in the past when they used more 3tb drives. Under 1/2 of 1% yearly failure rate, vs 1-3% for most drives, and up around 30% for some popular seagate models.

edit: the drives I mentioned are 3.5"
 

Rand__

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Mar 6, 2014
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3.5 drives are cheaper (per TB), hotter, faster.
2.5 are smaller
Pick your poison;)
I went with 8TB 3.5 but was looking into 5TB 2.5"'s as well - but too expensive yet for my taste.
 

StammesOpfer

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Mar 15, 2016
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3.5 are more common in the sizes that you would want/need. Also you have not mentioned what you are putting these in but any high capacity 2.5" drives are going to be 15mm high which may not fit in everything (typical laptop 2.5" is significantly thinner). Anyway seems the biggest reasonably priced 2.5" drives are 4tb. 8tb 3.5" WD Reds can commonly be found for good prices (both via shucking) At least in the rack mount world in 2u you get 12x 3.5" or 24x 2.5" so density would be the same unless you go for 10 or 12 tb 3.5" drives. 2.5" will pull more power considering you will have roughly 2x as many spinning for the same amount of storage. 3.5" price per TB will be lower.

Basically 3.5" has a lot going for it. 2.5" is great for some situations but generally for bulk data storage 3.5" is the way to go.
 

Evan

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Jan 6, 2016
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I would use 4 slots with 4 x 8tb helium drives, make mirrors and add them to a pool. 15tb or so of usable space. (1 would do that over 4 in raid z2)

The reason I say 8tb or larger is they use less power than the non helium or smaller drives.
 

Blinky 42

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Aug 6, 2015
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For bulk storage, go with big 3.5" drives unless you are very budget constrained or need high performance. You need a lot of slots of 2.5" drive to compete with even a mirror of 8TB or 10TB drives for usable TB/$. If you only have space for 6x 3.5" drives you should try and make the most out of it. If you need some fast and some bulk mix in some SSDs and then large bulk drives across your 6 slots.
 

TLN

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Feb 26, 2016
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Basically 3.5" has a lot going for it. 2.5" is great for some situations but generally for bulk data storage 3.5" is the way to go.
That's the answer I was looking for.
One question left is: should I do RAIDZ or something like that? Or run mirrors and call it a day?

I would use 4 slots with 4 x 8tb helium drives, make mirrors and add them to a pool. 15tb or so of usable space. (1 would do that over 4 in raid z2)

The reason I say 8tb or larger is they use less power than the non helium or smaller drives.
6x8TB drives are quite expensive and definately overkill for me. 3-4 drives is not that reliable
 

Evan

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Jan 6, 2016
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Maybe just 2 x 10tb WD gold and mirror, when you need space do same again. Simple and easy and can grow as needed. Look at how much data you actually need ? Can tv show downloads just be deleted after watching ? I have these day simplified my life and gone all flash but stopped storing most things after watching and mostly use streaming.
 

TLN

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Feb 26, 2016
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Maybe just 2 x 10tb WD gold and mirror, when you need space do same again. Simple and easy and can grow as needed. Look at how much data you actually need ? Can tv show downloads just be deleted after watching ? I have these day simplified my life and gone all flash but stopped storing most things after watching and mostly use streaming.
That's a good question. That way I can keep my existing pair, and still have some space for two more drives.
Main question for me is reliability: Raid Z vs Mirror.

Majority of data is photos/videos/documents plus music. Don't need all the shows all the time, for sure.
 

Rand__

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Mar 6, 2014
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Main question for me is reliability: Raid Z vs Mirror.
For Raid Z2 2 drives can fail but you need more drives to begin with (6 would be the usual recommendation)
A mirror can start with 2 drives (1 failure possible), or as a 3 way mirror (2 failures possible)
 

Joel

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Jan 30, 2015
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It's entirely possible to build a 4 drive Z2 array, and in some ways I consider it superior to mirrored pairs because a single drive failure doesn't cause a zero redundency condition.
 

TLN

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Feb 26, 2016
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It's entirely possible to build a 4 drive Z2 array, and in some ways I consider it superior to mirrored pairs because a single drive failure doesn't cause a zero redundency condition.
I see that, but it's lots of space unused.

So I'm looking at following options:
6-8x 2.5" drives in Raid Z2
6x 3.5" drives in Raid Z2
2x Huge drives in mirror and keep my existing 3Tb drives in mirror.
 

manfri

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Nov 19, 2015
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For storing these kind of thing i would consider not using a RAID at all.
Can be effective enough 2 drives, with some form of async replication (robocopy, rsync, pick your poison) nightly scheduled or even manual.
Not everything require 24/7 uptime and high performance I/O.
Pick different manufacturer drives and forget about raid recostruction times, raid level, etc etc etc.
for long term storage, pretty cold (as access, non temperature) a replica on archive type (high capacity, little cheaper) USB drive has the advantage that can be taken offsite, so even in case of disaster (theft, flood, fire) you can have your data safe.

I've done all of the above, 2 NAS with a simple 4 disk raid 5 with BTFRS so with a bit of maintance can be spotted data corruption, in different location in the building, one usually not even powered (so not problem of power consumption and hacker attack :cool:))) replicated async plus a backup on USB drive.