RAID 5 Initializing? WTF??

RAID5 stores its data across multiple disks along with parity information so that if one drive fails all the data is accessible and the failed drive can be replaced and the contents rebuilt. To do this the array needs to be initialised, either offline (no access) or online (user access allowed) before it's fully fault tolerant..

I'm guessing that your array is initialising online in which case there will be a degredation in performance for a few hours depending on the size of the array while all the parity blocks are written out. Any user requests to the array will have to contend with this process.

Your best bet is probably to leave it churning overnight.
 
rpstewart said:
RAID5 stores its data across multiple disks along with parity information so that if one drive fails all the data is accessible and the failed drive can be replaced and the contents rebuilt. To do this the array needs to be initialised, either offline (no access) or online (user access allowed) before it's fully fault tolerant..

I'm guessing that your array is initialising online in which case there will be a degredation in performance for a few hours depending on the size of the array while all the parity blocks are written out. Any user requests to the array will have to contend with this process.

Your best bet is probably to leave it churning overnight.
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What actually being done in the intialization

Is offline quicker and how do I do that?

Its 320Gb x 3 in the array
 
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The initialisation process sets out the parity and data blocks on the disk, the array will not be fully fault tolerant until the process is complete.

Offline will be quicker simply because the disks don't have to service any user requests alongside the initialisation but the time difference is going to be minimal really. It depends on the controller how you do an online or offline initialisation and these days it may be that offline is no longer given as an option.

Given that there's no real advantage timewise in an offline initialisation I'd just let the array do it's stuff overnight in whatever way the default is.
 
I was playing FM07, whilst installing Microsoft Defender and I got a blue screen.

The process khips.sys was mentioned. When I restarted, the raid array is initializing again, why and is this going to happen regularly?

I think the khips.sys is a kerio firewall thing but why would the raid array have to go through this again
 
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Ahh, it's not initialising in the true sense of the word, rather it's rebuilding.

It's something which can happen if the array is in the middle of a write operation when the PC crashes, basically the array has become inconsistent and the card is rebuilding the data on one of the disks from the data and parity on the other 2 disks.

Think of it another way, if that had been RAID0 rather than RAID5 you could very well have been dead in the water, the time a rebuild takes is nothing compared to recovering from backups.
 
Card? Eh No, I have onboard. Proper SATA RAID cards cost ridiculous amounts of money imo

I thought it would only have to re-write whatever stripes failed the partity check, this is going as slow as the initialization which took all day yesterday. :mad:
 
Dempsey said:
Card? Eh No, I have onboard. Proper SATA RAID cards cost ridiculous amounts of money imo
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That's why it's taking so long. On board RAID has no hardware support for the parity XOR calculations so it has to use the main CPU to do everything. As a result you're not only seeing a disk slowdown because of the read/write activity but also a CPU overhead of all the parity calculations.
 
I'm beginning to think that.

I'm now thinking of how to image the data on raid and then change my raid configuration, any recommendation based on the spec in my sig?

If I could find a decent SATA RAID controller, i would consider buying it as long as it isnt mad money. Where would I get one?
 
dempsey said:
any recommendation based on the spec in my sig?
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Do you need the redundancy you get from RAID5? Personally I only use it because it takes so long to recover 1Tb of stuff from DVD backups.

In your case your options are:

  • Stick with software RAID5
  • Invest in a RAID card
  • Move to RAID0
  • Use the 3 drives independently

Each has it's own merits and detractions. Software RAID5 offers redundancy at the price of vastly reduced write speed, an add-in card will give you better write speed at a cost, the more you pay the better the write speed will be. RAID0 is the ultimate in cheap performance but you'll lose everything if one drive dies. 3 independent drives will give you the full 960Gb of space but no redundancy although if one drive dies the other two will be fine.

Personally I'd go for the latter option unless you have a compelling reason to go with RAID5.

dempsey said:
If I could find a decent SATA RAID controller, i would consider buying it as long as it isnt mad money. Where would I get one?
Click to expand...

http://www.overclockers.co.uk/productlist.php?groupid=701&catid=49&subid=424

If you want RAID5 then the Highpoint 23xx controllers are the ones to look at, I'm not sure about the 2300 but the 2310 & 2320 are what is known as "accelerated software RAID5". They don't have true hardware XOR capabilities like the Areca cards but then again they cost a third of what the Areca does. Write speeds are about 45-60Mb/s compared to 15-20Mb/s with onboard RAID5.
 
Thanks for the advice, much appreciated.

The reason I'm choosing raid 5 is the amount of storage capacity I have and loosing one drive would drive me up the wall.

I had one of those Highpoints in my shopping basket when ordering my new build but I got it into my head that they were glorified onboard raid. D'oh
 
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