Converting disks to RAID - Help please...

First of all, thank you to all the experienced folks out there.... I've been reading a lot on this site and it seems to be one of the better sites to obtain information from.

Now, I'm going to worn you, I'm not experienced at this. I have loaded systems, but this one is different...

I have an Alienware 17 (mid 2013), with i7-4800mq, 750 gb hdd, 64 gb ssd. Last year the hdd went out, dell sent another and reinstalled my system. System never seemed fast after that...

Recently, I've acquired malware and my system just won't cooperate. I'm going to reload it. Data I need is off of it. I don't need anything on the drives.... **Please note though -- my Samsung PM830 64 GB SSD drive - I can't find the firmware on Dell's site, so anything I do can't hurt that. Dell can't even find the firmware...

In looking up all the info to refresh my memory, I've seen a lot about RAID. When I realized I could look up that information, I did. My bios (Insyde software - INSYDEH20), version 14, does have RAID selected. The RAID configuration utility lists both drives as non-RAID. Computer Management, both basic disks NTFS. I did manage to delete the ssd volume and change it to dynamic. I was able to change the hdd to dynamic.

Now, back to the RAID config utility when booting - I can only choose 2 options: create raid volume and exit. Create takes me to the screen to create, but the max size shows 119.2 gb. It doesn't tell me where that is, and doesn't seem to correspond to anything. In the utility, the hdd is listed as 698.6 gb and the ssd is 59.6 gb.

I'm trying to just set this up to run faster because even after they reloaded me, it was taking me a few minutes to boot. So, RAID 0 is what I'm looking for. I just can't figure out how to make it happen....

I've read many documents, but most are installing RAID on a new disk. I want to convert my current disks to RAID. I've just started by trying with the ssd, but both need converted. Also, I keep reading that I need to have the RAID drivers, which drivers? Just the drivers already listed on the drives in device manager? And, IRST needs to be installed, I get that... But, that doesn't happen until after Windows install, so can anyone tell me exactly what I need to do before/during the install of Windows. And, how do I create a RAID array? That seems to be an IRST function in windows, but I have no ability to create anything in IRST. --Might just be because the pre-boot utility says both are non-RAID...

I keep reading stuff, but so much of it is really old so I don't know if I'm just not putting it together or the info is outdated. It all doesn't seem to be... I think I'm just an idiot and obviously missing something important. Can anyone please explain my idiocy to me please?

Thank you SOOOOOO much in advance. Please don't beat me up too bad...

 

And, it might help if I tell you the op sys - Windows 7 home premium. Sorry about that....

 

To enable raid you need to have two identical sized HDDs .... so you need 2 of that 750 gigs HDD

 

I thought that was mirroring. Its like that on striping also?

 

AFAIK you strip on single HDD ... How to do it on the laptop though is unkown to me

 

Well, i played around with it some more and found if i shrank the hdd volume in windows it freed up the commands, so it was just waiting on room on a disk. Didnt set it that way though. Just wanted to see something that looked right...
I figured out i needed to actually changed the boot menu in the bios to choose the dvd first and using the f12 boot menu boot from dvd option will not work for the repair option on the windows cd. Im actually doing the clean on the hdd now. Clean all, actually...
Hopefully, i can fumble through the rest.... we'll see!

 

Hi, I am guessing you want the caching on the SSD back? As long as the RAID bios is active you simply re-install to the HDD and the SSD will be available for caching in IRST. In fact as long as you don't change any settings it will continue to work (it is in firmware and does not need an OS) during a complete wipe down and re-install. You never see that drive (ssd) in explorer, IRST hides it. You can see it in Disk Manager where you can delete the partition if it has a problem. DO NOT format it though, IRST has to see a blank un-partitioned space on the SSD to enable caching.

Hope this makes sense... ask away, haha

 

I cant say that i know what dell changed, but i could see the drive in explorer. I havent formatted it. It really didn't look like it was using it at all. The one folder it had predated the reinstall. Any clue how i get the machine set back up correctly to use the caching?

 

And, I'm having another problem... I ran diskpart clean all on the hdd and now I'm sitting with a status of failed on the volume. And, it seems to have created another disk while doing that. I no_ have an M0 disk that is missing. I can't seem to get either to change. I get CHKDSK the drive before this and no errors. Any clues how to fix this?

 

I figured out the failed status on the volume. Disk somehow converted to basic and I didn't do that unless I indirectly did it somehow. I deleted the volume, converted disk to dynamic and recreated the volume and now status is healthy.

I still have a missing disk problem though. Looking at disk 0, it is only 698 gb, which is a 750 gb drive. Maybe it is the remainder of that?

 

The ssd should be visible in Disk Manager. If it has any partition on it delete it so it is unpartitioned. You should also see where the missing gb are on the HDD in this utility.

Once it's blank just fire up IRST and it should detect the blank ssd and offer you the option for caching.

Good luck.

 

Just to clarify a few things:

Yes, that's because RAID 0 (stripe) and RAID 1 (mirror) need two identically sized drives. Since the 64GB ssd is the smallest of the two available the RAID volume you can create will be limited to 2x 64GB = 128 GB. The remainder 685GB of the hdd (750-64) would be unused and unavailable for anything else. As MickyD1234 said: no drivers necessary for it to work, the bios/raid firmware will hide both drives and present a single 'pseudo' drive to the OS (or its install CD).

Stripe needs two drives as well; all files are split and stored half each on the drives. So a, let's say, 3MB mp3 is split into two parts; 1.5MB on 1st drive, other 1.5MB on the second. Accessing the single file will now be done over two (m)SATA ports instead of a single one. Use 2x mSATA in RAID 0 on my laptop (for fast consecutive writes, mainly), this is no different from a desktop. The RAID controller's firmware takes care of all the nitpicking, drivers do not come into play.

However, you really don't want to stripe a (presumably) fast ssd with a slower hdd. Either use 2x 64GB ssd for a single ~90GB volume or use 2x 750GB for a 1.5TB volume. Cannot use the full 100% storage of an ssd due to overprovisioning, have to consider minus 25% of the stated storage size to forestall diminishing speeds over time.

Mind that the chance of disc failure with a striped volume is almost twice as high (not exactly twice because you have to subtract the chance of both drives failing at once). Actually, the chance that the mirror volume fails is also twice as high, except here ' failure of mirror volume' ≠ ' loss of data' (replace failed drive and the volume rebuilds itself). Doesn't do much good it the laptop's stolen, of course, so still a good idea to make a regular full-image backup.

 

I think you guys are getting confused over the caching that the 64gb SSD was intended for. When you set up caching a pseudo array is created on the HDD and then cached with the SSD. If at a later date you add another HDD this can be added as part of a single drive array. It's for this reason the RAID disk driver must be used even though technically RAID is not being used.

Not to be confrontational but I also believe overprovisioning is a hang-over from the early SSD days and is nowhere needed as much? Just what my research showed - no real world experiences...

Everything you guys say is correct but I think it might be confusing the original issue of a re-install with a 64gb SSD Cache?

 

Noted, thanks . Still, regular RAID is a possibility on this system, yes? Otherwise no menu would've been available, so you could stripe 1x mSATA and 1x 2.5" SATA ssd, outperforming the cache drive solution? Cache is fine and all, but not in all scenarios; won't do any good with large, consecutive writes nor for one-time reads.

OP is still necessary for garbage disposal, it's just that newer drives are factory-OP'ed, hiding the issue. Trim helps too, but only for as long as you still have spare capacity on the drive (non-factory op + non-trim or full disc should show the difference). Really, user-op on a trim-enabled system only ensures that trim will always function, regardless how much you fill up the drive. Prefer it that way; it'll force me to buy a new, larger capacity drive. Factory-op is much more honest to the buyer, but whether that decision was due to fairness or complaints ...

 

This is not strictly true. Mismatched devices can work. I've done it with 3ware controllers and with Linux DM-RAID. If you mix media in RAID sets then your available storage will be a multiple of the smallest device in the set. Nb: a given RAID controller might not permit mixing different media in traditional RAID sets, and I've not tried this with Intel RST so I don't know if it's permitted.

It's generally not advisable to mix media in RAID sets if the RAID controller or software does not explicitly support mixed media. Mixing media can lead to unbalanced I/O timings which in turn can cause data loss, especially when dealing with parity RAID (5, 6 and variants thereof).

Intel SRT (SSD cache) is a special case. It uses the RST RAID system to bond one HDD one SSD. Available capacity under SRT is the full capacity of the HDD. You cannot bond more than one HDD to one SSD; if you want to cache a second HDD then you need a second SDD.

As an aside, ATA TRIM is irrelevant for SRT cache.

Again, not strictly accurate. Striping (RAID 0) requires at least two drives. You can stripe many drives together. You can even stripe together other RAID sets. For example, RAID 10, aka RAID 1+0, is two or more RAID 1 (mirror) sets that are striped (RAID 0) together, and RAID 50 is two or more RAID 5 (parity) sets striped together.

Files are not split per se. Rather, each disk is divided up into stripes of typically 16K (flash) or 128K (rotating). These stripes are then interleaved to form a single large volume.

The points about performance and reliability are spot-on. Protecting your data are what backups are for.

 

Yes, hence " smallest of the two available", " 2x 64GB" and " 750-64".

Yes, thanks. Aware of that as well, only considered that too nitty-gritty for such shorthand. Do prefer a more accurate description any day though, so indeed, your explanation is far more accurate (and still succinct) .

Peace.

 

Yes it is so adding a second SSD is perfectly possible. That would outperform the cache but it's a very small amount I found in-use. 64gb is enough to cache windows and a few games at the same time. I did test a cached win load and it took around 2 seconds longer but the raid bios was then on so that overhead has to be added in. EDIT: Forgot to add when setting up the cache you have the option to delay writes (optimize for speed)so they only happen when the drive is idle - more dangerous as a crash can loose data.

It's actually an easy upgrade. Turn off caching and then create a RAID array with it and a second SSD. Same size for mirror style RAID but for a single large drive you can use mis-matched drive sizes (I believe, haven't tried that lately and at one time any RAID drives had to be identical?).

 

Yep. Looks like I missed that amongst everything else going back and forth.