Want to get a RAID 5/6 setup

Guest · Dec 31, 2015

I currently have a 256 GB 850 evo SSD and a 3 x 500 GB seagate external USB 2.0 HDDs (two of which are identical and used for weekly backups and the third is plugged into my PC 24/7) and some random external HDDs housing the rest of my not so important data. It has now come to my knowledge that using external HDDs 24/7 in such a way is not a good idea and I can see why because the hard disk pulling off 24/7 duty got corrupted, probably due to a power fluctuation because it kept connecting and disconnecting rapidly for 5 seconds and before i could do anything, the partition got corrupted. I was partially able to recover my data using recuva but I did lose some important data. I'm looking to invest in a more trust-able setup of internal HDDs.

I wish to get my self a RAID setup with some kind of HDD failure protection (RAID 5/6). Now the thing is that I have only 2 sata ports remaining on my mobo (I have an h81 mobo with 4 sata ports, 1 used by SSD, other by optical drive). I don't want anything more than 6 TB of storage as of now. Since 2 x 6TB HDDs are pretty expensive, I'm considering buying some kind of a RAID card, which I can use with my new NAS I'll be building in a year from now.
Now, according to this thread: http://serverfault.com/questions/685289/software-vs-hardware-raid-performance-and-cache-usage , RAID needs some kind of a power loss protection to protect your data (I don't really wan't to buy a UPS unless I really have to) and caching for good performance.

Which RAID card should I buy for my requirements ? Any specific kind of hard drives I should buy which has power loss protection (are hard drives even affected by power loss like flash based storage?) ? Also, why is software RAID preferred for an SSD based RAID setup ? You probably know by now that I am a noob when it comes to all this so please bear with me. Any help highly appreciated

saywhut · Dec 31, 2015

RAID 5 - minimum of three drives, and losing 1/3 of the space in a 3 drive config.
RAID 6 - minimum of four drives, and losing 1/2 the space in a 4 drive config.

That being said, you're gonna need a RAID card since your current setup only has room for 2 SATA slots.

For some hardware controllers that have cache, they usually have a RAID controller battery to preserve the data in the cache in case of a power outage. There's a lot of options for RAID cards out there, including Enterprise grade like the Dell PERCs, and those support SAS, so depends on how much you want to spend. SAS is designed to last longer than SATA, be on 24/7, and they usually have higher RPMs.

martinch · Dec 31, 2015

Personally, I use external HDDs for backups (kept unplugged unless in use), and haven't had a problem.

For your NAS, please consider using ZFS (e.g. via FreeNAS) and its software "RAID" (RAIDZ) feature - it is far more fault-tolerant than traditional RAID, as the blocks are checksummed, although it does need ECC RAM.

You'll want a battery-backed RAID card (Dell PERC, etc). Unfortunately, these are pretty expensive new (more than the cost of 2x 6TB WD Reds), although you can find used ones on eBay. The battery is not to keep the HDD spinning, but to keep the instruction queue in the RAID controller card held in memory, so it can resume when the power is restored (otherwise you end up with a "write hole" - the controller thinks the write completed, but it didn't).

Rogue Leader · Dec 31, 2015

A few things to know. First off yes HDD's are affected by power loss especially if they are in the middle of writing data. You want to know how you get bad sectors, thats how!

Secondly If you're building/buying a NAS next year, buying a RAID card is a waste of money. Most motherboards these days have between 4 and 8 SATA ports, so if you build a NAS just select a motherboard that has both RAID capability and the amount of ports you would like.

So you really need a solution for now, and then a solution for later. RAID 5 and 6 is for 3 or more drives. So if you wanted 6TB of storage you need at least 3 drives. Also there is no such thing as an HDD with power loss protection only SSD's, not only that every time they have tested it out, they found only uber expensive Intel SSD's does it actually work.

What I would do if I was you would be the following. I am assuming you're using your 2 external drives internally now. After doing that you can either use Windows 10's Storage Spaces to set up a two-way mirror, or use computer management to set up a Mirror (on Win 7 or 8). I can provide instructions if you need. This sets you up with a RAID 1, the drives are mirrored and if one craps you can swap it for a new one.

The only way to protect this from power loss is a UPS. If you lose power otherwise there is always a chance no matter what RAID setup you have for data to be damaged unless you buy yourself a high end cached, and battery backed RAID setup.

Worry about setting up your NAS when you build it next year. Of course what I am telling you here is more of a home/consumer setup. You can get a RAID card, and all of these things. You will spend WAY more money, they will work very well. But you mentioning in your first post how you don't want to spend extra for a UPS tells me you probably don't want to spend the large amount of money you will need to to do this right.

Guest · Dec 31, 2015

saywhut :

Can you please throw some light on how a power outage can affect your data, because I have had many power outages till now but my data seems to be perfectly safe. Also can you please give some recommendations on which RAID card and Hard drives I should purchase ?
In terms of drives, I was considering 5 seagate barracuda 3TB HDDs ( 2 for data + 1 for parity and 2 for an offsite weekly backup) but they do not have any kind of power failure protection (does your storage need such a protection if your raid card already has one built into it ?) Also, they seem to have a high failure rate. Which are my other options ?

For the RAID card, I don't necessarily have any budget. I want something which works fine, has powerloss protection hopefully has good linux compatibility if I might ever need it and some amount of future proofness, but at the same time not going overkill and overspending. Please recommend some models I can consider.

saywhut · Dec 31, 2015

So since it doesn't appear that you have a budget, a PERC H710 has a battery with 512mb or 1GB of cache.

So the way it works with the cache, is that the data written to those drives are written to the cache first,. Then the data in the cache gets written to the hard disks. The purpose of writing it to the cache first is because its much faster than writing directly to the slow platter drives. Also, when it writes to the cache, the computer thinks it sent the data to the drives, but it goes to the cache until the drives have time to catch up.

An H710 is probably way overkill for your setup. Perhaps you can do a RAID 1 with those 2 empty SATA ports using Storage Spaces from Windows 10.

Guest · Dec 31, 2015

Rogue Leader :

Ah thanks for throwing some light on power loss affecting HDDs. My corrupted HDD ended up having quite a bunch of bad sectors when I scanned for it.
"The only way to protect this from power loss is a UPS. If you lose power otherwise there is always a chance no matter what RAID setup you have for data to be damaged". Damn that hurt xD

@saywhut @rougeleader So for now if I just stick to software based RAID 1, what kind of internal HDDs should I invest in ? I'm done with using external HDDs for the time being.

Guest · Dec 31, 2015

saywhut :

So since it doesn't appear that you have a budget, a PERC H710 has a battery with 512mb or 1GB of cache.

So the way it works with the cache, is that the data written to those drives are written to the cache first,. Then the data in the cache gets written to the hard disks. The purpose of writing it to the cache first is because its much faster than writing directly to the slow platter drives. Also, when it writes to the cache, the computer thinks it sent the data to the drives, but it goes to the cache until the drives have time to catch up.

An H710 is probably way overkill for your setup. Perhaps you can do a RAID 1 with those 2 empty SATA ports using Storage Spaces from Windows 10.

That was some pretty helpful information, thank you!

Rogue Leader · Dec 31, 2015

Ok I'm glad we could clear this all up. What you are asking for in your initial post is like super overkill and something I would build for a business. It would help to know exactly what you're doing along with your concerns and a budget as well.

So if you're buying a couple drives for now I use Seagate drives always, however WD is just as good. Use the higher grade drives, not the Green ones. I just replaced my mirrored drives with 2 of these:

http://www.newegg.com/Product/Product.aspx?Item=9SIA2W01HP4646&cm_re=seagate_7200-_-22-148-834-_-Product

I had 2 1.5TB of the same drive, I replace my drives every 5 years, TBH 7 years is the most I would ever expect to get out of a consumer drive. They all fail eventually, they are mechanical.

Once you build your NAS buy the NAS drives, example:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822178393&cm_re=seagate_NAS-_-22-178-393-_-Product

They are made to run 24/7. Now depending what you're looking for in a NAS you can buy pre setup systems that have Drives, RAID configured, etc. Those will have power loss tolerance, and so on. But the truth is the UPS is the number one thing you can do to be sure you won't have your data get screwed in the event of a power loss.

saywhut · Dec 31, 2015

Rogue Leader :

Ok I'm glad we could clear this all up. What you are asking for in your initial post is like super overkill and something I would build for a business. It would help to know exactly what you're doing along with your concerns and a budget as well.

So if you're buying a couple drives for now I use Seagate drives always, however WD is just as good. Use the higher grade drives, not the Green ones.

Once you build your NAS buy the NAS drives, example:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822178393&cm_re=seagate_NAS-_-22-178-393-_-Product

They are made to run 24/7. Now depending what you're looking for in a NAS you can buy pre setup systems that have Drives, RAID configured, etc. Those will have power loss tolerance, and so on. But the truth is the UPS is the number one thing you can do to be sure you won't have your data get screwed in the event of a power loss.

I can vouch for these NAS drives, as I have the EXACT same drive (2 of them) in a RAID 1 in my QNAP NAS.

Guest · Dec 31, 2015

Rogue Leader :

Ok I'm glad we could clear this all up. What you are asking for in your initial post is like super overkill and something I would build for a business. It would help to know exactly what you're doing along with your concerns and a budget as well.

So if you're buying a couple drives for now I use Seagate drives always, however WD is just as good. Use the higher grade drives, not the Green ones. I just replaced my mirrored drives with 2 of these:

http://www.newegg.com/Product/Product.aspx?Item=9SIA2W01HP4646&cm_re=seagate_7200-_-22-148-834-_-Product

I had 2 1.5TB of the same drive, I replace my drives every 5 years, TBH 7 years is the most I would ever expect to get out of a consumer drive. They all fail eventually, they are mechanical.

Once you build your NAS buy the NAS drives, example:

http://www.newegg.com/Product/Product.aspx?Item=N82E16822178393&cm_re=seagate_NAS-_-22-178-393-_-Product

They are made to run 24/7. Now depending what you're looking for in a NAS you can buy pre setup systems that have Drives, RAID configured, etc. Those will have power loss tolerance, and so on. But the truth is the UPS is the number one thing you can do to be sure you won't have your data get screwed in the event of a power loss.

I don't really have strict budget as such. I'm willing to spend how much a good enough setup should cost, without going overkill.
I basically use my PC for my university projects and I kind of want my data to be pretty safe because all our research data plus data we get off other people's research is saved on the PC and is used for the projects and it pains to see our efforts go in vain due to a data loss (which happened to me a while back as I initially stated). I am planning to build a NAS so all our team members can access the data off it and the data is more safe than it would be on our local PCs.
Since ya'll say I shouldn't opt for a raid card now and wait for the NAS to be setup, I am now majorly concerned with my drive choices for RAID 1.
PS: I'm considering purchasing a UPS now because it scares me to not have my data protected from a power loss.

Rogue Leader · Dec 31, 2015

Ok so yeah for now the drives I linked are good enough to do RAID 1 (which is Windows 10 Storage Spaces two way mirror, or Win 7 Computer Management Mirror setup).

This is how to set it up in Win 7:

http://www.howtogeek.com/howto/17926/use-drive-mirroring-for-instant-backup-in-windows-7/

This is Win 10 Storage Spaces:

http://www.howtogeek.com/109380/how-to-use-windows-8s-storage-spaces-to-mirror-combine-drives/

Its a start

Guest · Dec 31, 2015

Thank you @saywhut and @rougeleader !

Guest · Dec 31, 2015

Omg I don't know how, I completely skipped your post @martinch !! Thank you for your input!

martinch · Dec 31, 2015

Personally, assuming you're an employee, I'd have a word with your friendly IT department - they should be able to provide some filestore space for you, or if it's not performant enough, they should at least be able to set up an automated backup regime for whatever you get (assuming this is an office PC, or you can connect it via VPN) - it might be easier than a DIY approach.

N.B. Staff setting up their own NAS/storage systems when they can be provided with a considerably higher-spec, fully redundant and backed up filestore they can use, but didn't ask for because they didn't realise it was provided, or thought they could do it better or cheaper themselves, is not a good way to ingratiate themselves with the IT guys.

(<< voice of experience from an IT dept drone)

Guest · Jan 1, 2016

martinch :

Lol I am a university student doing my masters in pure physics. The IT department in my university is basically just for maintaining the university intranet and don't offer any kind of tech support to us. We are in talks to setup a private SMB network in VLAN. If it works out then we will just purchase a NAS. The director of the university agreed to fund the NAS though. But I need a reliable solution for the time being.

martinch · Jan 1, 2016

Ah, sorry, misread a little then! Sounds like a reasonable approach then (I would strongly recommed looking at a FreeNAS-type solution with ZFS's RAID-Z for your NAS, and obviously NAS drives like WD Reds, when you build your NAS - it's enterprise-grade stuff, and standard RAID starts getting less than ideal with larger drives).

(if it wasn't obvious, I work for a uninversity IT department, and we offer filestore, supercomputer time, and coding support for research students upwards, which may colour what I say)

Guest · Jan 1, 2016

martinch :

Ah, sorry, misread a little then! Sounds like a reasonable approach then (I would strongly recommed looking at a FreeNAS-type solution with ZFS's RAID-Z for your NAS, and obviously NAS drives like WD Reds, when you build your NAS - it's enterprise-grade stuff, and standard RAID starts getting less than ideal with larger drives).

(if it wasn't obvious, I work for a uninversity IT department, and we offer filestore, supercomputer time, and coding support for research students upwards, which may colour what I say)

Thank you for your tips!

Want to get a RAID 5/6 setup

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