Intel Storage RAID5. What does "Initialize" do?

[evlap]

Hi All,

I've installed RAID5 with 3 disks using Intel Rapid Storage. The volume got created fine and I am able to use it. I noticed, however, that "Initialized" field says "No" and there is an "Initialize" command next to it.

Question is: am I required to perform the initialization to enable RAID5 protection? Or initialization is only required to restore volume consistency after ungraceful shutdown, etc...?

I would imagine that RAID5 redundancy is active from the time the volume is created, but still want to be sure.

Thanks

 

[NetworkStorageTips]

Initialize will wipe out data. Contact Intel Tech support with exact product details for support.

Ordinarily initialize is only used when first creating a RAID array.

I think it might say no as an indication that you have not requested it to initialize at this point in time; not that it never has been initialized - but I could be wrong.

 

[inzone]

If you install a hdd and windows does not see it then it needs to be initialized. When you initialize you are setting the partition size and then you would format that partition. If your drive is already partitioned and formated then windows will see it. If you are building a computer or changing your hdd setup and you create a raid and then load Windows 7 it will partition and format the drive.

 

[evlap]

NetworkStorageTips, thanks. I chose to initialize the volume and after the process has finished it now says Initialized. Still not sure why it didn't initialize automatically. The process took a few hours and I didn't loose any data.

 

[evlap]

inzone, thanks. I could see the volume in Windows and access it. What confused me was its not-initialized status.

 

[sminlal]

I'm not too familiar with the Intel RS stuff, but I can tell you this. The redundancy in a RAID-5 volume comes from the parity information on the drive. That information has to be written in order to be valid, and that process will take quite a long time (hours) for a modern with capacities measured in TB. If, during the process of setting up the drive, it hasn't gone through that lengthy initialization, then you don't really have redundancy.

Now there's a school of thought that says you don't have to initialize the parity information because when you first set up a drive none of the sectors on the logical volume are actually used for anything, and as you write the first bunch of data to each of those sectors the RAID controller will generate the correct parity for them and write it. So even though the parity information for most of the drive is not valid, it should be OK for all of the sectors which have actually had data written to them.

I don't subscribe that that idea because one of the things that a decent RAID subsystem should do is background parity checks of all the sectors on the volume. That's how you find out about problems before it's too late to recover from them and on large drives with relatively low reliability specs (most consumer drives are rated at 1 unrecoverable error per 10^14 bits read, which means even odds you can't recover from a drive failure in a 10TB RAID-5 array) you're asking for trouble if this doesn't get done. And it can't get done unless all of the parity information has been initialized.

 

[evlap]

Best answer selected by evlap.

 

[evlap]

Thanks for the in-depth explanation.

Now the big question for me will be to find out if Intel RS implements the background parity checks that you are referring to...

 

[paulie-d]

Intel Rapid Storage Technology is a Windows*-based application that provides improved performance and reliability for systems equipped with disks for desktop, mobile, and server platforms. When using one or multiple disks, you can take advantage of enhanced performance and lower power consumption. When using more than one disk, you can increase protection against data loss in the event of disk failure.

That being said, you will not be able to leverage the VERIFY AND REPAIR SCHEDULER functionality of iRST, until you initialize your RAID volumes via the Intel RST app > Manage > Initialize. According to the app's documentation, which is quickly accessible by clicking the "?" icon adjacent to the INITIALIZE link, it states:

"Initializing a volume is the process of synchronizing all redundant data on a volume prior to verifying or verifying and repairing that data. If you attempt to start a verification process for a volume that has not been initialized, you will be prompted to do so."

"Initializing a volume when verifying data
1. Under 'Status' or 'Manage', in the Storage System View, click the volume that you want to verify. The volume properties are now displayed on the left.
2. Click 'Verify'.
3. When prompted to initialize the volume before verifying data, click 'Yes' to start the initialization process. Caution: Once the data migration starts, the operation cannot be canceled.
4. Once complete, click 'Verify' to start the verification process."

"NOTE: While initializing is in progress, you can view the status in the notification area by pointing to the Intel Rapid Storage Technology icon, or in the application under Status or Manage Volume."

**** MOST SIGNIFICANTLY ****

Warning: The initializing process could take a while depending on the number and size of the disks. You can continue using array disks and other applications during this time. Closing the application OR powering off and restarting your computers will NOT disrupt the progress of this operation."

Hence, user "evlap" feedback from October 12, 2011 5:16:20 PM where stated "The process took a few hours and I didn't loose any data."

 

[Doctor Jones]

This is what the Intel RST documentation says:

Initializing a volume is the process of synchronizing all redundant data on a volume prior to verifying or verifying and repairing that data. If you attempt to start a verification process for a volume that has not been initialized, you will be prompted to do so.

So, contrary to what others have said, it will not delete your data if you initialize a volume from within the Intel RST Software. They seem to be confusing it with what initializing a volume means in Windows.

 

[Jacob_72]

I am using Raid 5 with Intel's RS and my drives are all 4TB this is my second day of initializing and ita only at 44% and still can't see the drives in windows or use them. is this common?