RAID 1 advice needed...

[joeMan]

Okay, so if I am mirroring in RAID1, and the primary (boot) drive crashes, is it just as simple as unplugging the crashed drive, replacing it with the one that's mirroring and firing up again and I'm good to go - kind of hot swapable like? Or is there more to it than that?

I have read some brief descriptions of the process in my mobo manuals, but I want to hear it from somebody who has been through it for real.

Also, I understand it is best to go fully hardware based RAID1 as opposed to software based - wht does this mean? What are the advantages/disadvantages of hardware vs. software RAID?

Thanks, jM

[Hawk]

Hardware RAID is the way to go.

Software RAID slows down the OS. Also, When a drive fails, like in a RAID 1 situation, you must unplug the bad drive, and modify the boot.ini file to point to the working drive. Windows looks at the partitions on the drive, not the drive it self.

[joeMan]

Thank you Hawk. Dependable as always.

Have you been through this Hawk? How exactly do you mod the boot.ini file on the "mirror" drive after the boot drive fails?

[Hawk]

Ok, remember this also:

1) XP Pro can do raid-0,1 with softare. XP home does not support it.
2) Using Windows software raid, you can't boot off it, It can only be used for DATA
3) If you want to boot off it you must use hardware raid(ex, ICH5-R), whether its an addon card or if your builtin controlers will handle it.


I'd stay clear from Software RAID, but if you must, here's pleanty of info:


Here's a link on some RAID performace on the ICH5 side.

http://techreport.com/reviews/2004q2/chipset-raid/index.x?pg=1

Also some MS stuff on Windows RAID:

http://support.microsoft.com/?KBID=114779

http://support.microsoft.com/?KBID=120227

[joeMan]

I'm not going the software RAID route. Thanks for the info. though, it confirms what I've read so far in other places. Hardware RAID is the only way I'll do it.

So, I still want to know how does one go about getting up and running when the boot drive in the array takes a $h!t? Like, pretend you have a RAID1 setup going and your boot drive craps out., but the backup (mirror version) drive is still in good shape - what do you do next to boot back up using the good drive?

You mentioned the boot.ini file modification, so if I cannot boot instantly in to that backup drive, how do I access the boot.ini file and what change do I make?


ALSO -


On a seprate not. What if I go RAID1 as stricltly a safeguard for my backup drive. i.e. I have a single boot drive and a secondary drive I use for page file, my docs, etc. Then, I regularly copy/backup all my important stuff over to a third drive that is configured RAID1 with a fourth drive. Like this:

HD

#1 - Primary boot
#2 - Storage, Pagefile, My docs

#3 - Strictly Storage/Backup (RAID1)
#4 - A mirror of drive 3 above (RAID1)

Now what if say, HD #3 crashes? Do I just keep on truckin' with HD #4 until I can get a replacement drive to rebuild the mirror to? And if so, will HD #4 just keep on going along without issue as if there is no problem at all? (assuming it's healthy).


Thanks very much for taking the time with this, I need to know because I'm going to reconfigure the two machines here at home, and also I want to know for installing systems for clients that do A/V editing, xfers, dupes, etc.

[pointreyes]

Actually there are three types of RAID 'controllers'.
Fully software based - like Windows XP/2000 Server/2003 or Linux.
Hardware that is NOT fully hardware based on the RAID controller- like my RAIDCore or the evil onboard Promise controllers. These controllers are commonly referred to as software controllers which helps to add to the confusion of what they are.
Fully hardware based - like 3Ware controllers.

The second option is the usual type that people use which entails the controller is using a chip for the algorithm for handling the RAID but the chip accesses the system's CPU for the power to derive the algorithm.

A Fully hardware based controller does not place demand on the system's CPU because it uses it's own processor the the algorithm processing.

I seriously dislike the software based RAID method. My preferences are a little more expensive but then again I don't like losing data by trusting a $5~15 chip on a motherboard or an OS that could croak from a drive failing.

[pointreyes]

Thanks very much for taking the time with this, I need to know because I'm going to reconfigure the two machines here at home, and also I want to know for installing systems for clients that do A/V editing, xfers, dupes, etc.

For A/V editing-RAID can be a problem. Normally using single drives for the A/V is safer and then use RAID for a backup solution. My AV machine is using 4 drives and no RAID.
Drive 1: OS and programs
Drive 2: AV drive 1
Drive 3: AV drive 2
Drive 4: Temporary backup and pagefile.

Why is RAID a problem, because I have heard the horror stories of an AV job going back and wiping out a whole drive that the AV files were being created on. RAID 1 could very well be mirroring what is getting wiped out. That happens to be one of the reasons why my RAID 5 is on a file server instead of on the AV machine. Once the job is completed it gets backed up to the file server.

[joeMan]

Thanks pointreyes - didn't know that about the semi-soft Mobo inherent RAID controllers. That is cool that fully hardware based controllers have their own proc.

[Hawk]

Joe,

If you have RAID / Hardware and the boot drive hits the shi**er, you'll be able to boot fine. :yup: Once you get a replacement drive you install the new drive and in the BIOS (for ex.) select the Regenerate. That will "SYNC" the drives.

Like PR said, with the 3, there are different ways to recover from a failure, but you will not have to play with the OS, the Hardware fools the OS and makes it think that it is 1 drive, when it is really 2 or more.

[joeMan]

Cool. Thanks guys.

[Ryan79]

I am in the process of setting up a RAID 1 system, I didnt plan on hardware raid and used this GUI to just set up the array, I go into windows setup and install the 2 RAID drivers for my board ( MSI k8n Neo2 - Plat) and windows continues and freezes at "Setup is Starting Windows"

If i go with Hardware Raid will this problem be fixed? Also what do you recommend? I want whatever is easier. This PC has been a problem for me with allk inds of defective parts and its not for me. SO whatever will make this go smoothly I would greatly appreciate.

Can contact me on msn at mrbored@hotmail.com or aim name is xxbulbyxx, I would really like if something could message me I have some other questions, kind of on a timeline here =/

-Ryan

[joeMan]

Ryan79 you may have to go in to the Mobo's RAID setup and configure that before you install Windows. My mobo has a hotkey you press during POST/pre-boot to get into the VIA RAID and another to get into the Promise RAID, and I told the mobo what kind of array I wass gonna be doinggggg before I even installed windaows. This process I just describes is hardware based.

[Killer Munkey]

question, how can you have a software raid? i thought you need a add in card with card capabilites or get a mobo with raid built into it otherwise you can't do it.

[joeMan]

KM I haven't done it, but have read that there is RAID from within Windows somewhere. Google it. Sorry I can't look into it more for you, I gotta jam - late for school!

Hardware based is most efficient. Software based uses more system resources to manage it all (if I'm not mistaken and if I have read this thread and other stuff on the web corretly)...

[Killer Munkey]

ahah, i see. Didn't know that you can use software to fake a RAID controller.

[pointreyes]

question, how can you have a software raid? i thought you need a add in card with card capabilites or get a mobo with raid built into it otherwise you can't do it.

http://www.techimo.com/articles/index.pl?photo=149
Warning: I'm a avid hater of dynamic disk arrays which is what you use with Windows to create software raid. I hate dynamic disks because they on occasion have a tendency to convieniently drop off in a strange non-consistent manner.

[Ryan79]

Ok then i guess i am doing hardware RAID im just using the controllers off the board, i thought you needed a RAID controller card to be considered hardware. Anyway, I did setup the drives in the bios, and told it which ones were for RAID, i dont know if there is another config to hit? I hit the shift f-10 or whatever to get into the screen whre it just lets me select the type of RAID and it sees the 2 drives.

[Ryan79]

Update: I have the channels on teh board activated for SATA, and the appropiate channels set to RAID (1,2) went into the RAID config utility where I selected the 2 drives picked mirroring strip size, and told it to make it boot. I dont know what else to do here. I boot into XP, hit F-6 install both drivers for my board, it continues and still freezes at "Setup is Starting Windows"

If anyone can contact me on messanger like previously requested I qould greatly appreciate it, pulling my hair out here =/

[joeMan]

Ryan79 - Sorry your having such trouble. I don't know what to say. I always just defined array in BIOS, (depending on what controller I used I would also set that array to RAID mode in BIOS, as opposed to IDE Operate Mode) - then like you said, boot with XP disc in ROM drive, hit F6 to install third party and just follow the prompts from there...

:scratch: I realy don't know why your getting the lockups?

I hope somebody else jumps in here soon...perhaps move this issue to it's own thread with a help header on it to grab the higher powers' attention. There are some sharp dudes around here so give that a whirl...