RAID1 Questions (And if you have a WD My Cloud Mirror, go to post #3 for a question)

[The Stig]

So after 2 seperate hard drive failure incidents that I couldn't help with (it's not exactly my area) I have been thinking of setting it up for myself as I'm becoming paranoid, but some questions remain. Was wondering if someone can fill me in on it.

1. I can't seem to find a straight tutorial on how to do it on Windows 7/Windows 8, or is there some software that can do this for me. I know I need 2 identical drives and a supported motherboard that has a RAID controller, which I presume most if not all modern ones have.

2. I know the drives need to be identical, but is that in terms of final capacity or hardware? The drives, after formatted and ready to use, their max capacity is somewhat variable (i.e. a 120gb drive might only have 108gb usable, but another 120gb drive may have 105gb...)

3. This question I can't seem to find the right answer to either, or a straight answer. So presuming one of my drives in the RAID fails, does the controller turn the working one into its primary drive with all the data accessible? Lets presume my RAID1 configuration also includes my OS on it. I'm guessing I can just tell startup to boot from the working drive and carry on as normal, if it doesn't do it automatically.

4. Following on from #3, if one does fail and I'm unable to boot from the system for whatever reason, can I just take the working drive and plug it into another PC or into a USB caddy and access my data? The reason for this question is that I'm concerned that something somewhere will stop me from doing so as it has lots its twin lol

(I know this is the point of RAID1 but ... like I say at work, it's not about the backup strategy, but the restore strategy... I understand it fully from the backup sense, but I cannot find answers to the "after failure" scenarios detailed above).

5. Just a simple one, in the RAID1 config, I'm guessing the secondary drive is not the one that's going to be read from, and only gets written to, or does Windows pick 1 of the 2 to access my data? I'm also presuming that once in a RAID1 config, I'll only see 1 of the 2 drives in My Computer and not both.

Bonus question: any recommended hard drive utilities that tells the health of my internal and external drives?

Thanks for reading!

[Niya]

RAID =/= backup, especially software RAID like the one you're planning. If the software screws up you can still lose all of your data, and as far as I've read about it in the last years you do NOT want to use any form of software RAID.
But to answer your questions:

#1 Windows can't do RAID, it's either configured in the BIOS/UEFI firmware or (most of the time) the driver/software for the SATA controller. Intel chipsets should let you configure it within RST as long as the controller is set to RAID mode in BIOS. Nor 100% sure about it, but AFAIK you can't setup RAID for your boot drive this way because it's more or less impossible to mirror the boot code.

#2 It's recommended to use "identical" drives, but in reality the RAID config doesn't really care if the total capacity differs. The array is as large as the smallest drive in the array.

#3 There is no primary/secondary, all drives are always active. They act as a single drive towards the OS, if you read data it gets read from both drives (double read speed), if you write something it gets written to both at the same time. And as already said in #1, with software-based RAID it might be impossible to boot from either drive since the boot code can't be mirrored.

#4 should work. The only difference between a RAID drive and a "normal" drive is that it has some meta data in the header part so the RAID software/controller can recognize it.

#5 see previous answers

Bonus: Crystal disk info should be able to read the SMART data from internal drives (btw, RAID config often kills that possibility since the RAID driver cloaks the individual drives towards the OS). External drives, might work, but probably not since the SATA-USB bridges usually don't allow access to SMART.

But as already said, if you want to use RAID, don't do it the cheap way or you'll probably regret it later. Anything that can only be configured from inside the OS is bad, decent RAID chips (either included in the mainboard chipset like LSI MegaRAID) or stand-alone controllers all have the option to config them from a BIOS-like panel during boot. Those also allow to config the RAID before installing windows, so boot code mirroring is no problem.

[The Stig]

Ok I see, so software can screw it up and alternatively it's configured from BIOS. Makes sense. Thanks for your info though, greatly appreciated.

It's not for backup purposes I guess, but I have this external hard drive I use daily which has data (media mainly and hobbies on a programming/code level that I toy with still) back from 2004~. Naturally I don't want to lose it as I've moved across hard drive to hard drive for the last 10 years.

If raid is going to be fickle, I suppose I can buy 2 brand new drives (my current one is at its capacity of 3gb) and then make it a weekly ritual to plug the second one and copy any differences over via SyncToy 2.1. The idea is if I raid it up then that cuts out the ritual, and also I don't have to keep switching the external drive on and off manually.

I was going to buy the WD My Cloud Mirror (built in RAID0/RAID1 or just combined into 8TB) but I didn't like the NAS aspect of it. I don't like leaving electronics on at home lol, and although I can map a drive to it I'm doubting if it would be as fast as an external drive. Anyone own one that can provide input? I just want to know if it's easy to shutdown or can I just flick it off, or so I have to navigate to its web control panel to do so.

[Niya]

NAS boxes with RAID1 usually are limited by the network interface and their processor, not the disks. My Synology NAS has a read speed of about 60-65MByte/s through wired gigabit, write speed should be around 20-30MByte/s (mostly limited by the RAID code that stresses the processor). Better NAS boxes with more potent processors usually give you full wire speed for read and write, with SMB (windows shares) that ranges around 60-80MByte/s.
A directly attached USB3 drive might be faster (~100MByte/s), but with a NAS and an external drive attached to the NAS for occasional backup copies you have 3 copies of your data as opposed to a single copy on an external HDD.

[The Stig]

I see I see.

Presuming your NAS (Synology, I heard it before for sure and I remember reading about it) is similar to WD (or is it just an enclosure?) do you:

1. leave it on
2. if not, is it easy to shut down? (i.e. I rather not just power it off, as it's probably not good for the drive, but I was wondering if a power button on the enclosure exists where it would gracefully turn it off so it don't screw up anything)
3. you say you can attach external storage to it, I noticed it can be done on the WD My Mirror too... does it support self powered USB drives? (I'm guessing this varies by product) I rather not micro manage an external USB drive that requires power lol

[Dantrag]

How many disks does the NAS have?

All drives lose 7-8% disk space with formatting. Or is it 3%? I forget.

How many disks does the NAS have?

[The Stig]

The WD Cloud My Mirror has 2 disks, the one I am edging on buying is 8TB total capacity, 4TB when Raid1'd. The reason why I am buying that is because my mum works for a company that sells them and offers perks/discounts so I'm getting it far cheaper than I would off the market price.

I'm just curious if I should go with an external solution or an internal one. Less management if I went internal (it's always there, and is on), some micromanagement if I went external (gotta power it up and down; I don't like leaving things on if not being used) and some mapping stuff required.

[Dantrag]

Can you link it? Also, can you get a 4 bay instead of 2? Raid 5 is much better for redundancy that a 2 bay. I use a 4 bay external with 4x4 which gives me around 10GB of storage with redundancy which I use for my Plex server files.

[The Stig]

It's basically this thing here: http://www.wdc.com/en/products/products.aspx?id=1200

It's very .... consumer (user) friendly. It'2 bay only I'm afraid, and I guess you meant 10TB rather than 10GB?
I'm not too confident in buying a blank NAS box and setting up my own at this point in time. The idea of it being constantly on irritates me slightly but I'm willing to accept a NAS if I can power it off and on easily when not in use. I'm sure it's simple though ... buy NAS box, fill out all slots of hard drives, turn it on, let the onboard stuff do its wizardry, fill her up.

Thanks for your interest/replies on this by the way.

[Dantrag]

Yeah TB. My bad lol.

Blank NAS boxes cos a lot more so if that's a restriction I wouldn't worry about it. I got mine for free. It's always on but it's quiet. It's pretty much put all drives in. Login to it. Assign it a name and IP and then have it create the raid. It's pretty simple if you have a slight bit of tech savvy.

[Niya]

Mine runs 24/7 since I use it as a seed box xD But pretty much any NAS should have a power button to turn it off gracefully. Or you can schedule power on/off via time tables.
But with todays HDDs that are certified for 24/7 usage (like WD Red) it's not a problem to let it run all day. Mine has run with WD Greens for years already without any trouble, but i'll probably switch to larger WD reds soon.

With external storage i primarily meant "attach external HDD, run backup, unplug it again and store it somewhere else". Keeping it attached all the time would ridicule the extra safety of a backup...
If you mean wire-powered (not external PSU) HDDs, they might work, but since most external HDDs draw more power than the USB standard allows (that's why those stupid Y cables exist...) i'd say probably not.

Dantrag, the capacity "loss" is not due to formatting but because HDD manufacturers and OSes count differently. Those "2TB" on the HDD package are based on 1000 bytes per MB, but any OS (correctly) counts with a 1024 bytes per MB base. That's why you never get your 2TB but instead ~1,78TB.

€dit since I didn't see the last posts in time:
IMHO RAID5 for personal usage is overkill unless you really need the huge capacity and can't reach it with RAID1. Not to mention that at least on low-end RAID chips and NAS boxes the performance of RAID5 is lower than RAID1 since the parity calculation stresses the processor more.

And Stig, doesn't really matter if you buy it blank and put in your own HDDs or buy one that is already filled, either way you have to run the setup wizard of the NAS OS to setup RAID, network settings and other stuff.

[Dantrag]

^ you're right sorry. Here's a better explanation:

I always figure .93% of the drive manufacturers rated capacity is what you'll have after formating the drive
because advertising a drives larger size is just a marketing gimmick. Which one would you think the average
non technical informed Joe schmoe would be more interested in buying, a drive advertised as 1TB or the same
drive advertised as 930GB remember advertised size sells the bigger the better.

120GB x .93% = 111GB
250GB x .93% = 232GB
300GB x .93% = 279GB
500GB x .93% = 465GB
750GB x .93% = 697GB
1000GB or 1 TB x .93% = 930GB

[Obsidian]

I don't have a lot of experience with RAID configurations but if you're going to do it I think you want at least three drives, so that if one fails you can continue to use your machine (although I would replace the dead drive ASAP because if another one fails before you do I think you're SOL).

Edit: How I didn't notice this thread already had a dozen responses, I will never know.

[The Stig]

No worries. Just bouncing ideas around. Currently looking at:

Primary (boot + apps I wanna load quick) = SSD; won't have anything important
Secondary = A drive with other apps and files I don't care about
Third+Fourth = RAID1 internal drives or NAS box with my working files/stuff I don't wanna lose in one go

But yeh I'm going to continue digging around. It was nice to get inputs here.

but if you're going to do it I think you want at least three drives, so that if one fails you can continue to use your machine

I'm not too sure if I understand your logic here. Niya has explained that the boot drive can't be RAID1'd so that'll be pretty moot at this point. And I'd have to be rather unlucky to have the second RAID1'd drive fail before I get to replace the primary one. Possible, but still ... !

[orinthia]

Windows can "raid" in software, be it striping, spanning, or mirroring, but relying on windows to do it is a bit ehh. It's really easy to setup though, and mirroring can be done with your boot drive too ( https://www.youtube.com/watch?v=RT_0lNZ57k8 ). Just go to disk management and right click on a drive; you'll get a bunch of options ("new striped/mirrored/spanned volume"). Having dedicated hardware is better for performance and pure separation of tasks, but it's not the only option you have.

Mirroring is good mostly for 2 drive setups, but usually doesn't give much performance change. Striping with parity, with a few more drives, gains performance while allowing a certain number of drives to fail. So say you have 5 drives; you could stripe them where you have 3/5 of the total space but allow for 2/5 to fail at any time (2/5 of the space is for parity). Just when one fails and is replaced, the rebuild on the new drive can take hours or days depending on how large the drives are and how fast their I/O is. The performance boost though comes with the striping itself: you're not relying on a single drive to read/write data, you're having each drive participate in writing or reading separate data. It's why raid0 is such a big boost (especially if you did this with SSDs lol), but with no redundancy any single drive failure is a failure of the whole. Raid10 (raid1+0) can come in, mirror the whole thing while it's completely striped, but that's a little extreme. Raid5 is striping with parity, allowing for failures to happen while not being super redundant like raid10 (more space available from the whole).

There's also another thing about this: since the data is striped, all the drives need to be active to do anything, so the noise, heat, and power usage might be worth considering. It's also why when one drive fails from an all-new-drive raid setup, the others are likely soon to follow and a race against the clock begins while rebuilding.

If you're wanting to raid for just media drives, like in a NAS or something, "RAID" isn't the only option for redundancy. There's unRAID ( http://lime-technology.com/technology/ ), zfs, storage space (if windows server based), and a few others. And instead of buying a standalone piece of NAS hardware, you can just build your own out of a mATX/mITX board, your choice of proc (like intel atom/celeron or amd e-series/neo), and have as many drives as an mATX/mITX box can hold while supplying your own OS and configuration. For bigger numbers of drives, this is the cheaper option. For an OS there's FreeNAS, unraid (free version allows for 3 drives only), windows server for storage spaces (can be had for free as a student) and a few others; most can be run off a usb stick to leave the drives untouched (derp windows though).

[bungiefan]

^ you're right sorry. Here's a better explanation:

Except the difference gets exponentially greater the larger the drives get. The percentage of space you get because of the unit difference falls as drives get larger. It's never going to be the same unit, so the 93% thing isn't going to hold against the large drives now available.

[Hellfury]

No worries. Just bouncing ideas around. Currently looking at:

Primary (boot + apps I wanna load quick) = SSD; won't have anything important
Secondary = A drive with other apps and files I don't care about
Third+Fourth = RAID1 internal drives or NAS box with my working files/stuff I don't wanna lose in one go

But yeh I'm going to continue digging around. It was nice to get inputs here.



I'm not too sure if I understand your logic here. Niya has explained that the boot drive can't be RAID1'd so that'll be pretty moot at this point. And I'd have to be rather unlucky to have the second RAID1'd drive fail before I get to replace the primary one. Possible, but still ... !

The setup you describe above is roughly what I have.

SSDs for System+Games.
HDD for less important stuff, that I still want on local computer.

NAS for everything else, the entire family share 2x NAS, one small 8TB Buffalo (RAID1 on 2x2 TB for backups and 2x Standalone disks for just a bunch of crap) and one bigger Synology that has RAID5 (3x3GB for critical stuff and 2 standalone 4 TB disks for just junk, also has solutions for working as streamserver, vpn server etc.) in addition to a "server" that's VPN'ed to wherever we need.

the WD Red series was mentioned, they also have a "Pro" version of that but those are meant for 8+ drive systems.

You can have RAID1 on the system drive, windows can do it trickily, or you can get hardware that does it for you (some MBs have this), I used to do this before I went down the NAS route.

As Orinthia pointed out, you can also build your own, but on the relatively small scale you describe, I doubt it'll be cost efficient.

[The Stig]

Was interesting exploring various options. I have no intention to share what I store; and for some reason it's looking cheaper and cheaper to just buy 2 5TB external drives and make it a ritual to sync them weekly/monthly lol. Butttt, see below:

On my travels just now, I found that WD do a none NAS version of the "Duo" range of products, which actually sounds massively ideal to me. They're just a pair of RAID1'd drives in an inclosure:

eBuyer = respected UK retailer for PC stuffs
http://www.ebuyer.com/661686-wd-my-b...b85eb0fad5c1d1

Infact WD also has it up on their own store: http://store.westerndigital.com/stor...psrid=69044058 || the none NAS version also has 2 WD Reds inside!!! (not stated on the eBuyer site)

Looking at the price, it's £100 cheaper than the NAS option for the same thing. I'm actually going to consider this. I thought this type of solution was only possible with NAS (and the fact high street retailers carry the NAS versions only but not the none NAS convinced me it was NAS only until I saw this)

(I have some sort of loyalty to WD)

edit: seems like they do a 12TB version too, which I presume houses the recently released WD Red 6TB. Might shoot for that to future proof myself. But it's out of stock ... but I'm in no specific rush.