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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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 Posted: Tue Nov 26, 2013 1:26 am Post subject: [SOLVED] How to dual boot Windows on FakeRAID and Linux |
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Hello,
I read that it is not advisable, to install Linux on a so called Fake-RAID, since Linux might detect the HDDs/SDDs separately and not as a RAID-Drive.
Are the RAID-Levels offered by the current Intel-Chipssets Fake-RAIDs? eg. Z77 Z78 X79
Last edited by Dippmopser on Sun Dec 01, 2013 3:16 am; edited 1 time in total |
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frostschutz
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Joined: 22 Feb 2005
Posts: 2977
Location: Germany
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| Posted: Tue Nov 26, 2013 1:42 am Post subject: |
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Yes, they're all fake raid. A real raid controller costs money, several times more than the average mainboard. And it's questionable at best whether they really offer anything in return.
mdadm is a great raid solution and it's free, just get any mainboard that offers enough SATA ports for your needs. |
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Jaglover
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Joined: 29 May 2005
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Location: Saint Amant, Acadiana
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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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| Posted: Tue Nov 26, 2013 11:43 am Post subject: |
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Hello,
thanks for the answers.
Thing is I already own a Hardware-Raid Controller (LSI MegaRAID SAS9271-8i).
At the moment I am using a X79 Mainboard (Sandy-Bridge-E CPU). Said Mainboard offers only 2 SATA3 Ports. Since those Marvell-Onboard solutions are really crappy (even when using Windows) and Haswell (offering 6 SATA3 Ports) was not on the market at that time, I opted for a Hardware-RAID-Controller, to provide 8 additional SATA3 Ports.
This thing has been working very nicely so far. The only draw back is the elongated bootup-duration. Since I am now using Linux and Windows in parallel the boot-process when switching OSes costs more time than the heightened bandwidth saves.
Therefor I though about going for a Haswell CPU and selling the Hardware-RAID.... on the other hand it is really nice to simply installing OSes, without configuring the RAID anew every time and the RAID can be merged into new Hardware-environments, something I like as well. |
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depontius
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Joined: 05 May 2004
Posts: 3509
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| Posted: Tue Nov 26, 2013 11:55 am Post subject: |
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| Dippmopser wrote: |
Thing is I already own a Hardware-Raid Controller (LSI MegaRAID SAS9271-8i).
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Do you own one, or more than one of those cards? I have a data-paranoid friend who for years insisted on running hardware RAID, and he always had two controller cards. Your data lives and dies with that card. His second card was there to recover his data, if the first card died. If that happened, he'd then either fix the dead card, find a third identical card, or buy a two new cards. I don't know that he ever had a RAID controller failure, but it just illustrates the point. Your single point of failure moves from the hard drive to the RAID controller card, but it's still a single point of failure.
He's now running in-kernel software raid, delighted with the performance, and never looked back.
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John R. Graham
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Joined: 08 Mar 2005
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Location: Somewhere over Atlanta, Georgia
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| Posted: Tue Nov 26, 2013 2:41 pm Post subject: |
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Your data-paranoid friend has a misconception: RAID is not a substitute for a good backup regimen. None of my data lives and dies with my hardware RAID cards. Not that a spare isn't a good idea if you like the configuration: I have had card failures.
- John
_________________
I can confirm that I have received between 0 and 499 National Security Letters.
Last edited by John R. Graham on Tue Nov 26, 2013 2:43 pm; edited 1 time in total |
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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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| Posted: Tue Nov 26, 2013 2:43 pm Post subject: |
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| Quote: |
So, why wouldn't I want to use a RAID array built with mdadm? Really the only reason you wouldn't is if you needed to (heaven forbid!) boot non-Linux OSes on the same set of drives.
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There you have it, right now I am running Windows and Linux from the same RAID-Array. Something that would be impossible with mdadm or Fake-RAID.
Now if I ditch the Hardware-RAID, I could only opt for:
1. No RAID at all
2. Installing Windows on RAID A and Linux on RAID B - Windows utilizing Fake-Raid and Linux utilizing mdadm.
Option 2 two means that the space on my 4 drives cannot be distributed freely amongst partitions, since those are now limited by the extension of the physical drives (or separate RAIDs build thereof), not to mention that each RAID only has the bandwidth of 2 SATA-Channels instead of 4. |
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depontius
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| Posted: Tue Nov 26, 2013 9:19 pm Post subject: |
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| John R. Graham wrote: | Your data-paranoid friend has a misconception: RAID is not a substitute for a good backup regimen. None of my data lives and dies with my hardware RAID cards. Not that a spare isn't a good idea if you like the configuration: I have had card failures.
- John |
No, he's REALLY data-paranoid. He had the spare RAID card, and he backs up onto tape. You're right, he could just recover from backup, but that's awfully time-consuming.
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NeddySeagoon
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| Posted: Tue Nov 26, 2013 9:36 pm Post subject: |
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Dippmopser,
There is a third option. Windows Dynamic Disks. Thats software raid for windows. Linux understands them too.
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Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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John R. Graham
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Joined: 08 Mar 2005
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Location: Somewhere over Atlanta, Georgia
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| Posted: Tue Nov 26, 2013 11:11 pm Post subject: |
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| depontius wrote: | | No, he's REALLY data-paranoid. He had the spare RAID card, and he backs up onto tape. You're right, he could just recover from backup, but that's awfully time-consuming. |
Then I must be REALLY data-paranoid, too. 
- John
_________________
I can confirm that I have received between 0 and 499 National Security Letters. |
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frostschutz
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Joined: 22 Feb 2005
Posts: 2977
Location: Germany
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| Posted: Tue Nov 26, 2013 11:14 pm Post subject: |
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If you know the raid layout of the hardware controller, the data does not die with the controller. You might even be able to read it out of the box with software raid solutions, if it's a common format. It's something you have to determine once...
| Quote: | | Therefor I though about going for a Haswell CPU and selling the Hardware-RAID.... |
Well, that's pretty much my setup now... ASUS Z87-Pro with 8 SATA Ports; 1xSSD, 7xHDD (four of which formerly resided in a NAS I no longer use). I put in two cheap ($10 each) PCI-E SATA Controllers, for DVD, a single Hotswap-Bay, and 2x eSATA as I have some external enclosures that don't support USB3. |
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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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| Posted: Sat Nov 30, 2013 10:15 pm Post subject: |
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OK thanks for all the answers so far.
I gave it some thought an have another question:
Let's assume there are 4 SSDs, three of which are in a Fakeraid, while the last drive is a stand alone.
Now I am going to install Windows on the 3 SSDs in Fakeraid, which will work, since Windows can handle Fake-Raids.
Thereafter I will install Linux on the stand alone drive. (I do not really need RAID on Linux doing mainly office-stuff).
Now comes the big "BUT" and I hope you can give me an answer here:
When installing GRUB(2), which can be installed on the standalone disk, since I do not care, where the bootloader resides, will GRUB be able to chainload windows on the Fake-Raid? Will Windows even be dectected? Or may this even break the Windows installation?
Regards
Dippmopser |
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NeddySeagoon
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| Posted: Sun Dec 01, 2013 12:02 am Post subject: |
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Dippmopser,
Bootloaders work with BIOS block device references.
Providing the fake raid set appears as a block device to the BIOS, it will work.
It follows that Windows could not boot from the fakeraid either if it did not appear as a block device to the BIOS.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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| Posted: Sun Dec 01, 2013 2:02 am Post subject: |
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Just to keep you posted:
Since I am curious about such thing I gave it a try.
I removed the LSI, so thos drives are not seen anymore by the rest of the system.
I inserted 3 HDDs I had laying around, since I did not want to destroy my gentoo and windows setup just for testing purposes.
2 of those HDDs are now in RAID 0 (FakeRaid)
1 drive is a standalone
Now Windows is installed on Fake-RAID
Ubuntu 13.10 (forgive me here - I just dont want to sacrifice the time of installing gentoo for this) is installed on the standalone drive
Now to my first results:
While installing Ubuntu i saw that Fake-RAID really is prolbem with linux. The device partioning during install totally messed up with strange entries that did not made much sense to me.
The stand alone drive was detected correctly. I did the installation there and told to ubuntu to setup the boodloader on the standalone drive.
I rebooted and no GRUB-Selection-Screen appeared as it booted into ubuntu.
So far so bad.
I rebooted again and entered BIOS, where I can select the devices to boot from (boot overwrite). The Fake-RAID does appear there and once I selected it Windows booted up.
Some further details: The Mainboard I am using is a Gigabyte X79-UP4 (BIOS Version F4). In BIOS I can set 3 different modes: EFI / EFI and BIOS / Just BIOS - here I chose "just BIOS" since that yielded the fewest problems with GRUB and I do not need Fast-Secure-Whatever-Boot, since I do not run Win8.x.
To sum things up, via BIOS I can boot Windows, simply starting the PC and doing nothing boots ubuntu. So I can access both systems, although the way to accomplish this is far from what I might call optimal.
I'll try something else and see if that works ...
EDIT 1: I can change to BOOT-Order in BIOS. The Fake-RAID appears the as well. Putting it on the first place, causes the system to boot windows, putting ubuntu on the first place causes it boot ubuntu.
EDIT 2: I found a much more elegant solution to this Problem. It is called EasyBCD (it is free for personal use) and can be downloaded here: http://neosmart.net/EasyBCD/
A guide how to set this thing up, can be found here: https://neosmart.net/wiki/easybcd/dual-boot/linux/ubuntu/
Once again sorry for using another Distro and posting about it here, but I have no reason to believe, that it wont work with gentoo as well.
...
I change the topic title, as to reflect more accurately where this conversation headed. |
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NeddySeagoon
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Joined: 05 Jul 2003
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Location: 56N 3W
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| Posted: Sun Dec 01, 2013 11:01 am Post subject: |
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Dippmopser,
It will work with Gentoo too.
There are other solutions you have not explored. You can make Windows chainload Linux.
You don't seem to have made Grub chainload Windows.
The fakeraid looks an ugly mess to fdisk (and there are errors in dmesg) because it is showing you the component drives and if dm-raid is installed, /device/mapper/<your_raid_stuff>.
In a raid0 set, the partition table appears only on the first drive. The second drive appears to be unpartitioned. However, the partition table on the first drive describes all the space on the raid0, so dmesg tells you quite correctly, that it won't fit on the drive.
It all works properly when you access the fake raid through its /dev/mapper node.
_________________
Regards,
NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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Dippmopser
Tux's lil' helper
Joined: 22 Jun 2013
Posts: 92
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| Posted: Sun Dec 01, 2013 12:49 pm Post subject: |
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Hi Neddy,
I tried to Chainload Linux from Windows, to do so, I followed a guide, that can be found here (German): http://www.linux-community.de/Archiv/Tipp-der-Woche/Linux-im-Bootmanager-von-Windows-7
That however did not work for me, I followed all the steps there:
First:
run
| Code: | | sudo dd if=/dev/sda5 of=./linux.bin bs=512 count=1 |
in Linux (replace sda5 with whereever grub is at home)
Second:
Copy the file you just created onto your Windows-C-Partition.
Third:
Run the following commands in Windows Console (Run -> CMD (as administrator))
| Code: |
bcdedit /create /d "Linux starten" /application bootsector
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This will yield you a CRYPTIC OUTPUT of numbers, that you copy or note down.
Than run:
| Code: |
bcdedit /set {CRYPTIC OUTPUT} path \linux.bin
bcdedit /set {CRYPTIC OUTPUT} device partition=c:
bcdedit /displayorder {CRYPTIC OUTPUT} /addlast
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Of course here you replace the CRYPTIC OUTPUT-Part with the acutal numbers Windows gave you.
I tried that and after rebooting and selection the entry from the windows bootloader I ended up with a terminal cursor blinking on the upper left of my Display and nothing further happend.
EDIT: A Word of warning:
Since I set up the system for testing purposes, I tested gparted as well, since you might run into a scenario where resizing or adding partitions becomes necessary.
gparted has utter problems detecting anything.
You get a lot of error-messages, those you can:
1. Ignore - this shows me just one drive of the Fake-RAID (with a presumably unknown filesystem), while the standalone HDD is not detected at all.
2. Tell gparted to fix those errors (given the option) - this will break the Fake-RAID and yields otherwise the same results as above.
My personal conclusion from this experiment:
If you do not intend to setup a Dual-Boot System, that is not touched again after installation, do not use Fake-RAID (suprise suprise), it is not worth the hassle. |
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Installing Gentoo
