Raid 1 vs Raid 5

Etheco

Etheco

Etheco

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What do people generally setup in there home servers?

I am looking at trying to get a home server setup for as cheap as possible but do want a decent amount of storage.

WD Black apparently do not work well with Raid 5 and only suitable for Raid 1 and you have to use Red for Raid 5/10
 
Depends what you're after really. RAID 5 will give more capacity (and I think performance) over RAID 1 but obviously needs more disks.

The problem with RAID 5 is it'll only handle 1 failure and requires all remaining disks to be present when recovering. This means there's a chance another disk could fail (especially if you're rebuilding a big array with lots of data) rendering the entire volume useless.

No idea why they'd say it's only suitable for RAID 1 :rolleyes:.

I personally have RAID5 on my server as I have a full online backup plus a separate backup to an external, so double disk failure will be a bit of a pain but not a disaster.
 
I read some thing about that in the past because I thought the exactly the same thing, the manufacture process is no different but they set some different options on the disks that optimises it for the nas compared to stand-alone disk.

I used some standard disks in raid 5 before and it made no difference.

http://www.seagate.com/tech-insights/why-nas-hdd-master-ti/

its the Extended error recovery flags that they change, but hardware wise they are the same as far as i understand it.
 
Long and the short answer is that it's marketing and not a whole lot else.

https://www.backblaze.com/blog/hard-drive-reliability-q3-2015/

BackBlaze are running thousands of disks, and publish a reliability report quarterly :)
Some drive models are better than others, but that doesn't necessarily correspond as to whether they're Black, Red or anything else.

The only hard and fast rule you should follow is backing up elsewhere anything you can't afford to loose.
RAID of any description will sooner or later fail, even if it's only because your house caught fire.

-Leezer-
 
I use raid-5 accross 5 different 4 disk arrays at home.

Any "must not lose" data is synced to the cloud... but most of it is replaceable media - so if the whole array failed - it would be annoying but not troublesome.

That way out of 20 disks, I am able to use the full space of 15 disks. If using raid 1, I would only have the usable space of 10 disks.

For home use, raid-5 definitely makes the most sense... there was no viable reason to lose so much storage space or add 50% to the cost for the same storage space by having to buy 30 disks instead of 20 disks.
 
Thats great, Thanks all. I plan to sync anything really important to the cloud eventually but i have shocking upload so i can't rely on cloud all the time :)

Will it matter performance wise if i had like 2 WD 2TB drives 1 Seagate 2TB and 1 Toshiba 2TB and placed that in a Raid5, I assume long as the drive sizes are the same i can put any manufacturer into the raid.
 
me too... 1 mbit at the moment - it's painful coming from years of 10-15-100mbit uploads!

Ah well... back to Switzerland in two months and I'll be back to 500/15 until they make the upload symetrical in my new location :D






Any manufacturer is fine :)
 
crinkleshoes said:
me too... 1 mbit at the moment - it's painful coming from years of 10-15-100mbit uploads!

Ah well... back to Switzerland in two months and I'll be back to 500/15 until they make the upload symetrical in my new location :D






Any manufacturer is fine :)
Click to expand...

Haha yeh my upload is 60kb/s :( still patiently waiting a year for fibre! i hate you BT i hate you!

And sweet, gonna keep a eye out on deals tomo/friday! :D
 
As far as I'm aware, BackBlaze aren't using hardware RAID at all, so are free to use any disks they like.

However, if you are planning on using hardware RAID, there are definitely some considerations, mainly that the RAID controller must have absolute control over the drive at all times. If a drive decides to go off and do checks, or has extended timeouts, or spins down, etc., you will be in trouble and the array will constantly break.
 
As rotor said, 'Green' drives tend to have quite aggressive spin down times which doesn't go well when in a RAID array.

Whether NAS targetted drives like WD Reds have any actual benefits over 'standard' drives I really don't know, but I do have 4 x WD Reds in my microserver, so I'm not one to judge...
 
The Reds used to have longer warranties than the greens as standard, I don't know if that's changed... also, like you mention - the spin down times aren't quite as aggressive, so they play nice with hardware raid.
 
I'm using the ZFS equivalent of RAID50 on 2TB disks.

Gives me enough protection to swap a disk if one fails while maximising usable space. All my important data is backed up nightly to two seperate locations in two different countries.
 
I only bring it up as running them in 50 is higher load on the drives and higher risk of data loss than running 6-drive raid 5 which would give you more usable storage space...

There's no fault tolerance between the two raid 5 arrays.

With "only" a 1gbit internal network, you wouldn't be able to max the speed of a single 3-disk raid 5 array... it's only worth the effort if you crave the peak transfer speeds, IMO
 
Its purely for convenience as it keeps the disks as a single pool. Resiliency isn't *that* much of a concern, the bulk of my data is Bluray and DVD rips so while the loss of a RAIDZ vdev would be a pain it wouldn't be the end of the world, and as I mentioned all the important data is shipped off to a dedicated server nightly which then runs a nightly backup to Amazon S3.
 
But what I mean is... you could switch those 6 drives into a single raid-5 array, you'd then have the improved resilience, as well as an extra 2TB worth of storage available and keep the single pool...
 
crinkleshoes said:
But what I mean is... you could switch those 6 drives into a single raid-5 array, you'd then have the improved resilience, as well as an extra 2TB worth of storage available and keep the single pool...
Click to expand...

I see your thinking, and I agree theres plenty of benefits and it wouldn't be ideal in an enterprise enviroment, but it doesn't give me the expandability of the method I've used either.

I can add another 3 disk RAIDZ vdev to my pool when I get short on space again. Then if space becomes an issue I can swap out drives in triplets for larger capacity (Using 2TB at the moment as thats the limit for the SAS 6/IR I'm using at the moment), running them as a single Vdev would mean buying 9 disks in one hit to either create a new pool or expand the existing one disk by disk.
 
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