RAID 5 -- recover files?

Micheline
Micheline used Ask the Experts™
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Server 2008 Standard -- SQL 2014 -- Need to recover two folders from RAID 5 (4 disks).    System failed to boot and rather than spend incredible amounts of time (beyond attempting to boot to 'last known' or attempt 'safe mode'), just popped in four new drives and reinstalled operating system and SQL2014.

However, I need a couple of folders off the broken array.   Any suggestions on how to get these rather than send the drives out?   It sure would be nice to get the server back online so staff can come back to work.  (sigh).
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JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
You now have 4 drives on the floor that were your drives and the RAID has been broken because you attached new drives to the existing controller.

So:  Send them out  OR  if you can, recover from backups.
Paul MacDonaldDirector, Information Systems

Commented:
You don't explicitly say this, but I presume the operating system was on the RAID array.  Do you have any reason to believe the system failed to boot because the array was bad, rather than the OS just having become corrupt?

Was this a hardware RAID or software RAID?  If you can plug the 4 drives in to a system that has a separate boot drive, I can't think of any reason why the array wouldn't let you access the data on it, unless the array itself is faulty.
MichelineSystems Administrator

Author

Commented:
Yes, the OS was on the RAID and yes, I believe it was in fact an OS issue.  But..... the hardware/software person that built the server for us ... way back when.... didn't give us the DVD's for the OS.   The tag on the side of the box says Windows Server 2008 Standard, but when I created a DVD from the ISO I downloaded from microsoft's site, the repair attempt said that the CD didn't match the OS on the hard drives.     Didn't feel I had too much of a choice than to put in four new drives, install an evaluation copy of Windows Server 2008 Standard R2 (which I had), just to buy us some time.    Reinstalled our SQL 2014.   didn't think things could get much worse, but our backups aren't restoring.  The logs say the backups were successful.....  

So here I sit with four RAID 5 drives where ALL I need if a couple of folders off it.   Any suggestions?   Other than sending it out.......
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JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
The data is / was written across the drives, so you need a RAID specialist to try to recover.
Paul MacDonaldDirector, Information Systems

Commented:
Despite what John says, all you need is a system that can access the drives.  That's why I asked if this was a software RAID or hardware RAID, and if the RAID was intact.

You'll need a system with a boot drive (to boot off of, duh), and which can accept the RAID drives exactly as they were in the old server.  If you can't re-create the RAID yourself, you will have to send them off.

Your best bet may be to try to put them back in the old server along with a bootable drive and see what you can do.  If you can boot an OS, and the OS can see the RAID array (as a single drive), you should be able to get your data back.
MichelineSystems Administrator

Author

Commented:
It would be sooooo much simpler 1. if my backup/restore would have worked  OR 2. a software app existed that would allow me to plug in one RAID drive and have it  visible.   sigh....
Bartender_1Microsoft Network Administrator

Commented:
I have had good success with Raid Reconstructor from Runtime.org

https://www.runtime.org/raid.htm

If you have a system that can run all the drives at the same time, you can use raid reconstructor to analyze the disks and report back to you whether or not it can read the data, before you purchase a license.

Things to be aware of with raid reconstructor:

You need to be able to read all the disks on a single computer.
It will automatically determine the parameters necessary to read your raid.
You will need a location that will be able to store the entire contents of the raid, as it creates an image from the raid on a separate location. You can then recover your files from the image.

Hope this helps!

Bartender_1
David FavorLinux/LXD/WordPress/Hosting Savant
Distinguished Expert 2018

Commented:
The simple approach, remove your new drives... install old drives... fix actual problem that started this entire sequence of events.

This is likely best, because if you attempt placing your 4x drives into some other RAID enclosure, if there's any mismatch between format expected by controller + format of actual disks, your data will end up destroyed.

At this point, I'd tend to agree with John + I'd go one step further.

When you send off your disks to a recovery specialist, also best to send the actual enclosure too.
MichelineSystems Administrator

Author

Commented:
Thanks Bartender_1!   I will take a look and see whether it's something I can do.
MichelineSystems Administrator

Author

Commented:
Hi David,

Sending out the drives is not possible.   The two vendors I received quotes from want anywhere from $5,000 - $10,000.   We are a very small company and do not have those kinds of funds.   They were not able to be absolute on pricing until they examined the drives to determine exactly what is wrong.
I will second Paul's and Bartender_1's suggestions.

Paul's should work if you can have access to the original server.  Just be careful when you tell it to allow the old array.

I've used Raid Reconstructor a few times with great success.

The software does an excellent job of identifying the original parameters and shouldn't do ANY writing to the old drives.
David FavorLinux/LXD/WordPress/Hosting Savant
Distinguished Expert 2018

Commented:
Ridiculous price.

Likely many people posting to this thread will help your for an hourly rate.

A reasonable price will be $100/hour or so, keeping in mind bill may be low + response may be "After an hour I determined your data is corrupted beyond repair".

Tip: Don't attempt to boot your disk array. Rather, connect your disk array to an already working machine, so your disk array is only a data device. You may find this resolves your problem.

Trick: If your RAID controller is build into your motherboard, then attach another Linux boot disk to your motherboard via another disk header + mount your RAID array as read-only. Most motherboards with RAID controllers also have one or more non-RAID disk headers/connectors.

I've had to do this a few times over the years when Windows became corrupt on a set of disks connected to a machine with a RAID chip on the motherboard.
Bartender_1Microsoft Network Administrator

Commented:
It should be noted, that when you install the drives into another computer, do NOT allow the computer to format the drives. RAID Reconstructor will see the drives as long as the computer can see the drive is attached.

Bartender_1
David FavorLinux/LXD/WordPress/Hosting Savant
Distinguished Expert 2018

Commented:
Mention if your RAID system is built into the mother board or is a separate device, like a NAS enclosure.

This is a big factor in how you'll recover your data.
Philip ElderTechnical Architect - HA/Compute/Storage

Commented:
We've done quite a few recoveries on failed RAID arrays using RAID Reconstructor by RunTime Software (linked above).

Make sure nothing has touched the drives and get that process started.
MichelineSystems Administrator

Author

Commented:
The RAID is in the server enclosure hooked up to a PERC 5/i RAID controller.    Not sure how many SATA's I can attach to my desktop.  I'll have to open it up to check.  I'll need six (my desktop OS, four for the RAID drives and one to copy the image that RAID Reconstructor is going to generate).
yo_beeDirector of Information Technology

Commented:
As others stated, is this Hardware or Software RAID? If it is hardware RAID you should see the RAID initiation during POST.  Can you confirm whether it is HW or SW RAID?

On a side note:
Personally I think you are up a creek without a paddle.  Sounds like your system was built by someone that had zero clue about RAID and the proper/ best practices for a SQL server.  The recommend RAID setup for SQL  should consist of two Raid 1 logical drives  and 1 RAID 5 logical drive

Logical disk 1 = RAID 1 = OS and Programs
Logical disk 2 = RAID 1 = Transaction logs
Logical disk 3 = RAID 5 = Databases
This recommendation will be good for the future when you rebuild this system.

Part two:
Lesson learned TEST TEST TEST TEST your backup integrity.
Bartender_1Microsoft Network Administrator

Commented:
In the event you have a computer that can't connect all of the drives at once, you can connect the drives one at a time and create an image of the drive, then use RAID Reconstructor to recover the raid from the images.

See here for a video on the process:
https://www.youtube.com/watch?v=DWNq5rAhZ9Y

Bartender_1
The default location for SQL files is in a squirrely place so it may well not be included in the backups and things can get worse if someone chose a custom location for the database.
Did you try booting the original drives into Safe Mode? (F8).
If you can get there, you can inspect the event logs or maybe even check what the RAID control software has to say.
If it was hardware RAID5 with a PERC, then as long as it was only an OS issue and not a hardware RAID failure, then you can always put the drives back in, boot the server with any drive imaging software and image the array.
Top Expert 2016

Commented:
Server 2008 Standard -- SQL 2014 -- Need to recover two folders from RAID 5 (4 disks).    System failed to boot and rather than spend incredible amounts of time (beyond attempting to boot to 'last known' or attempt 'safe mode'), just popped in four new drives and reinstalled operating system and SQL2014.

That was a mistake since your backup solution's recovery wasn't tested and as we all know Backups's always say they succeeded, restores not so much.

put the drives back and import the foreign configuration. you can use the boot options to then boot from an alternate Operating system. and copy off the data you require. If the configuration is not able to be imported then Raid Reconstructor is your only hope

SQL DATA locations are normally in C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQLSERVER\MSSQL\DATA
MichelineSystems Administrator

Author

Commented:
Gave one of the RAID 5 drives to a local IT guy I know, The Computer Guy and he was able to get my SQL *.bak file for me.    I don't know what software he used.   I'll post it here when I find out.   Now to figure out how to restore the *.bak file.    Thanks for all your help guys!   I guess you can well image what I'll be doing this weekend after I get the server totally updated and running smoothly..... :)
yo_beeDirector of Information Technology

Commented:
Are you 100% sure you had a RAID 5. From what I know about RAID 5 all your bits are spread across the entire array of disks and there is not a single complete file on any one disk. So for one single disk to have the compete .bak file seems almost impossible.

If you really have the full backup on a .bak fully intact you can restore it pretty much to any MSSQL SERVER.

Good luck.
MichelineSystems Administrator

Author

Commented:
Absolutely sure it was a RAID 5.  I viewed the RAID configuration prior to replacing the drives with new ones so that I'd configure the new array the same.  I don't know what program The Computer Guy used, but kudo's to him!   As soon as he gets back to his home, he'll text me the software name and version.    I'll post it here.  The prompts in SQL to restore aren't familiar to me, so I've posted a new question in the SQL forum.
MichelineSystems Administrator

Author

Commented:
Yes yo-bee.... lesson learned!   Absolutely will test this weekend and make sure all is as it should be!    This has been a painful process!
Bartender_1Microsoft Network Administrator

Commented:
If it was a proper RAID 5, then it would not be possible to extract data from a single disk from the RAID.

See here for how RAID 5 works:
https://searchstorage.techtarget.com/definition/RAID-5-redundant-array-of-independent-disks

If you gave this person a single disk and they gave you data from it, either the original RAID was not a RAID 5, or it's going to be corrupted data.

I would recommend you verify the data before doing anything with the original disks.

Bartender_1
yo_beeDirector of Information Technology

Commented:
Most of our learning experience is from our F&@$ups
Distinguished Expert 2017

Commented:
perc 5/i? do you have another system with this controller (spare, not in use).
One: while the drives are still out, boot the system and get into the RAID controller ctrl-R
Clear the controller's config.
Insert the four drives in the same positions as the one from which you pulled them.
 load the configuration from the drives.
The controller should now show you the RAID 5 volume in optimal state using the four drives.
DO NOT INITIALIZE/CREATE .....


use a bootable USB/CD/DVD to boot the system. depending on which you use, you may need to load the PERC 5/i drivers to have the ability to see the data.

much depends on which folders..if the bootable USB has the space, you could copy the data back to the USB. ...
Top Expert 2013

Commented:
did you identify how the Original raid setup was?  i mean how the disks connected to the controller?
then - maybe- we can get further
MichelineSystems Administrator

Author

Commented:
Hey no_bee

The recommend RAID setup for SQL  should consist of two Raid 1 logical drives  and 1 RAID 5 logical drive

Logical disk 1 = RAID 1 = OS and Programs
Logical disk 2 = RAID 1 = Transaction logs
Logical disk 3 = RAID 5 = Databases
This recommendation will be good for the future when you rebuild this system.

Please excuse my ignorance.... so
one physical drive RAID 1 for OS & Programs -- Virtual drive by itself
one physical drive RAID 1 for Transaction logs -- a new virtual drive by itself
three physical drive RAID 5 for Databases - a new virtual drive by itself.

five physical drives and three virtual drives (RAID 1 - 2VD and RAID 5 - 1VD)
MichelineSystems Administrator

Author

Commented:
Arnold.... too late.   I already gave all of the drives to The Computer Guy yesterday evening.  He has successfully in the past restored files from a RAID software program.   Hopefully we'll know the results soon.
yo_beeDirector of Information Technology

Commented:
No.

1 Logical Drive = RAID 1 = 2 physical drives (OS & Programs)
1 Logical Drive = RAID 1 = 2 physical drives (Trans Logs)
1 Logical Drive = RAID 5 = 3 or more physical drives + 1 Hot Spare for good measure.

RAID 0 = Stripe without parity (Looks like one large logical drive, but if you lose one you lose data)
RAID 1 = Mirroring of 2 drives = (Looks like one logical drive, you get the fault tolerance (can lose a drive and still work), but you do not gain any capacity.
RAID 5 = Stripe with Parity = Slower performance and can lose up to 1 physical drive and still function without any data lose.  You get fault tolerance
RAID 0+1 = Stripe with Mirror (more capacity than RAID1, but you do not gain as much space as RAID.  You do get much better performance than RAID 5.

I would never create a RAID with any VDisks.  Only create a RAID with physical disks and put the vDisks on the Array.
MichelineSystems Administrator

Author

Commented:
kk   Thanks yo-bee.   I am putting a proposal together to replace this old Dell PowerEdge 840 along with it's ancient Server 2008 Standard R2.   but this is for another thread entirely.   :)
yo_beeDirector of Information Technology

Commented:
were you able to restore the db?
MichelineSystems Administrator

Author

Commented:
As of this morning (36 hours later), it's still in the process of restoring.   The bar keeps moving, so .......    I'll be ecstatic if this works, but I'm not very optimistic at this point.   I'll post once it's successful or totally bombs out.
Nb - RAID-5 is no longer recommended for disks over 750GB , per spindle, please use RAID6 or RAID10
MichelineSystems Administrator

Author

Commented:
Thanks Gerald!   Looks like I have alot of researching to do.
Can you try a parallel install on the old RAID?  you can use any os.
MichelineSystems Administrator

Author

Commented:
David McCarn,  yep.... tried the F8.   Would come up.  Hung on loading the crcdisk.sys file.
MichelineSystems Administrator

Author

Commented:
| In the event you have a computer that can't connect all of the drives at once, you can connect the drives one at a time and create an image of |  the drive, then use RAID Reconstructor to recover the raid from the images.
|  
|  See here for a video on the process:
|  https://www.youtube.com/watch?v=DWNq5rAhZ9Y
|  
|  Bartender_1

Thanks Bartender_1 ......   I will definitely try this.   The guy that took my hard drives hasn't been successful.   At this point it doesn't really matter anymore.   So much time has passed that I recovered the  data from a viable backup that was ten days old.   So we're in the process of determining 'where' the lost data is and reconstructing it.   At least we're back online.   A new backup software has been installed  with the SQL Add-on and major testing to be done this weekend.
CRC (Cyclic Redundancy Check) is, fundamentally, a sum of the ones bits created each time a sector is written and then verified each time a sector is read.  99+% of the time, CRC errors indicates a drive is failing.  With a RAID array, the process would be to determine which drive(s) it is then clone (sector-by-sector copy) that (or those) drive(s) to get away from the hardware issue. Afterwards, use RAID Reconstructor (or something like it) to recover the data from the clones.  It is something I have done numerous times; though it can be tedious and time consuming.
Top Expert 2013

Commented:
update  the BIOS  on the RAID card, and install the latest driver for the RAID card
see:   https://community.spiceworks.com/topic/117069-server-2008-x64-hangs-on-reboot-as-crcdisk-sys
Systems Administrator
Commented:
There are several very good suggestions above.   As mentioned, we've accepted the 10-day loss of data and will purchase the RAID Reconstructor software once our new server comes in.  I'll use the old one as a testing ground.   The new server will be ordered in a couple of months (before my 180 day evaluation runs out for Win 2008 R2) and I will use the drive configuration suggested by yo-bee and Gerald.   Purchased BackUpAssist along with the SQL Add-on.... will test backup AND restore 'til I can't take it anymore.   (huge grin)    Looks like I've got a busy few weeks ahead of me.    Now if only I didn't have several other hats to wear at work!  (smile).  Again, thanks everyone for your input.   LOVE this forum!
yo_beeDirector of Information Technology

Commented:
Please note that my RAID config is based on a physical SQL server and not a VM Guest.  
If you are building a Hypervisor there are other best practices for RAID configs

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