Author Topic: Verify & Sync task vs Create Parity task  (Read 23230 times)

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #15 on: July 10, 2013, 05:07:12 pm »
Ok. Once we start talking about performance tuning, some of these tests will be re-evaluated.

I am suspecting that some of the changes to ensure greater data integrity is affecting different systems differently.
I would have been great if we could bypass this crippling during RAID initialization. However, many of the settings are system wide and cannot be turned on and off without rebooting.
 

Offline priley2327

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Re: Verify & Sync task vs Create Parity task
« Reply #16 on: July 10, 2013, 08:44:06 pm »
No, "I'll rather be a slow turtle so I don't get run over".  ::)


But if your a slow turtle and in the middle of the road what happens?
"We can't solve problems by using the same kind of thinking we used when we created them."
-Albert Einstein

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #17 on: July 10, 2013, 08:57:26 pm »
But if your a slow turtle and in the middle of the road what happens?

/facepalm

Offline NLS

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Re: Verify & Sync task vs Create Parity task
« Reply #18 on: July 11, 2013, 02:15:43 am »
Hahahahahahaha!
---
NLS
Production system: SBS2011 fully patched, intel Core2 Quad, 8GB, 12 disks (1 system IDE, 1 backup IDE, 10 for array and parity most SATA3), parity is 3TB, largest data disk is 3TB, millions of smaller files, common browser Chrome latest.

Offline vletroye

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Re: Verify & Sync task vs Create Parity task
« Reply #19 on: October 24, 2013, 04:06:51 pm »
I come back on this topic...

I am wrong or it's not possible anymore with RC10 to use "Verify & Sync" to initiate the Parity ?
I did try to start a new array to create its parity, then abort and finally use "Verify & Sync" but this one was disabled :(

To initialize the Parity (I did it twice), it took 33 hours with a mean throughput of 240MB/s (and a max of 252MB/s).
I am now running a "Verify & Sync". It's running with a mean throughput of 450MB/s. It should complete, without anything to sync, in less than 20hours - But I will report ;).

I would like next to remove one DRU (which is 100% empty), recreate the array from scratch and initialize it using "Verify & Sync"... But it will only be possible if I find how to do that with RC10.


Also, I have ordered a new 3TB disk. When it will arrive, I will add it into the array, move some data from the other disks onto that one and could try to recreate the parity using "Verify & Sync"... I will also report on that test here...

V.
« Last Edit: October 25, 2013, 12:52:05 pm by vletroye »

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #20 on: October 24, 2013, 05:03:42 pm »
What do you mean it is not possible?

The options the initialization panel gives you are pretty clear and include Verify & Sync.
Post a screenshot of what you claim is disabled.

Offline vletroye

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Re: Verify & Sync task vs Create Parity task
« Reply #21 on: October 25, 2013, 12:09:18 am »
When one wants to initialize the parity on a new array with Verify&Sync, one has first to click on start, then abort and finally click on Verify&Sync (That's how I used to do it with the early RC).

But now the Verify&Sync button keeps disabled after aborting the initialization ?!
« Last Edit: October 25, 2013, 01:09:21 am by vletroye »

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #22 on: October 25, 2013, 08:19:33 am »
When one wants to initialize the parity on a new array with Verify&Sync, one has first to click on start, then abort and finally click on Verify&Sync (That's how I used to do it with the early RC).

But now the Verify&Sync button keeps disabled after aborting the initialization ?!
What's the matter with some of you in coming up with some the craziest schemes ever?  ;D
How about not abort after clicking start and being shown the proper initialization panel?  ::)



It might help to go back to the wiki for a refresher. ;)
http://wiki.flexraid.com/2013/06/27/creating-a-transparent-raid-array/
« Last Edit: October 25, 2013, 01:15:09 pm by Brahim »

Offline vletroye

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Re: Verify & Sync task vs Create Parity task
« Reply #23 on: October 25, 2013, 12:46:51 pm »
?? I am lost....

What I want to validate is that "Verify&Sync" is faster than the "parity initialization"...

On the wiki it seems that the button "Verify&Sync" is enabled even if the array has not yet been initialized ?!
But it's not the case on my server ?!
Reason why I was trying to use this dirty trick found ages ago  (and not working anymore) :-[

Could you confirm that "Verify&Sync" is enabled on your machines for newly created arrays ?
« Last Edit: October 25, 2013, 12:50:34 pm by vletroye »

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #24 on: October 25, 2013, 01:31:46 pm »
I had placed an image, which was not showing.
Fixed. See the post above. Initialization is done on the "Initialize RAID" panel.
What you do anywhere else does not have the same meaning.

All array must be initialized.
If you want the different initialization options, you can un-initialize the configuration through the advanced operations menu.

Now, it has been discussed in this very thread of how Very & Sync is faster only when you had parity created before using the same disks. On a fresh new set of disks that have not been through  tRAID, the regular Create task should be faster.

Offline vletroye

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Re: Verify & Sync task vs Create Parity task
« Reply #25 on: October 25, 2013, 03:07:31 pm »
 :o

I saw that screen about one thousands of times and never really payed attention on the 2 first entries  :-[
Incredible how a brain can filter information  ::)

Thx a lot for your patience  :D

V.

Offline Brahim

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Re: Verify & Sync task vs Create Parity task
« Reply #26 on: October 25, 2013, 04:09:48 pm »
:o

I saw that screen about one thousands of times and never really payed attention on the 2 first entries  :-[
Incredible how a brain can filter information  ::)

Thx a lot for your patience  :D

V.
lol!  ;D
Oh, I believe on how it can happen.
I sneaked up and added those while you weren't looking.  :P

Offline erfa

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Re: Verify & Sync task vs Create Parity task
« Reply #27 on: November 09, 2013, 07:45:42 pm »
Recently I switched from RAID-F to tRAID, after replacing my OS (from win7 to win8.1). I've been using RAID-F for about a year and a half, and I haven't really had any problems with it. My only issue was that it took a lot of time to get it up and running and to figure out some of the features. So before setting up tRAID I looked into several alternatives, mainly Windows Storage Spaces and StableBit Drivepool. Storage Spaces was particularly interesting since it was a free option in win8. But I was quickly disappointed, I guess from hearing about it I had bigger expectations. So next I tried Drivepool, and I have to admit that I really liked how simple it was. They have really nailed the interface and ease-of-use. I think even my parents might be able to use it without any help. Unfortunately it only has duplication of data, no parity. Which doesn't work well for me, IMO it's too much of a waste of space. FlexRAID is by far a more flexible solution than any other I have looked into. My only issue still remains the usability of the product.

Now back to the main reason I'm writing this post. After going through all the necessary wiki pages to figure out how to set up my tRAID pool, and following the instructions to the letter, I was taken by surprise near the end of my setup. As recommended I chose to "Create RAID Parity" when initializing the RAID (the other available options were "Do nothing" and "Verify & Sync"). I had to wait 11 hours for it to finish. 11 HOURS?! I can understand if the data disks had a lot of data on them and the parity had to be recreated, but all the disks in my array were empty and formatted. So what gives? Is this normal? What is it doing during all that time when there is no data on the disks?

Another thing that seemed a bit odd to me was that "total size" = 10.916TB in the report (screenshot attached). But I was more curious about the issue above that I didn't give it any further thought. What is the total size supposed to be? It can't be the size of the parity created or the total amount of data on the DRU's, or even the sum of capacity on all the disks in the array.

Oh I almost forgot, here is some info about the PC I'm running tRAID on. I plan to continue using these disks, and gradually replacing the DRU's with WD Red 4TB. Now my fear is that it will take many days to recreate the parity with 4x 4TB.

DRU1 - 1 TB (931.513 GB) - WD Enterprise 7200 RPM
DRU2 - 1 TB (931.513 GB) - WD Enterprise 7200 RPM
DRU3 - 2 TB (1.819 TB) - Seagate Barracuda Green 5900 RPM
PPU1 - 4 TB (3.638 TB) - WD Red 5400 RPM

CPU: i5 2500 3.3GHz
RAM: 2x 4GB
OS: Win 8.1 Pro 64-bit (running on Samsung 840 Pro SSD)

Sorry btw. for the lengthy post :)
« Last Edit: November 09, 2013, 07:51:36 pm by erfa »

Offline terrastrife

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Re: Verify & Sync task vs Create Parity task
« Reply #28 on: November 09, 2013, 08:56:47 pm »
Now back to the main reason I'm writing this post. After going through all the necessary wiki pages to figure out how to set up my tRAID pool, and following the instructions to the letter, I was taken by surprise near the end of my setup. As recommended I chose to "Create RAID Parity" when initializing the RAID (the other available options were "Do nothing" and "Verify & Sync"). I had to wait 11 hours for it to finish. 11 HOURS?! I can understand if the data disks had a lot of data on them and the parity had to be recreated, but all the disks in my array were empty and formatted. So what gives? Is this normal? What is it doing during all that time when there is no data on the disks?

Another thing that seemed a bit odd to me was that "total size" = 10.916TB in the report (screenshot attached). But I was more curious about the issue above that I didn't give it any further thought. What is the total size supposed to be? It can't be the size of the parity created or the total amount of data on the DRU's, or even the sum of capacity on all the disks in the array.

You are creating parity for the disk/volume, not the data, hence disk full or empty, it will take the same time. Creating initial parity is the same for any form of RAID, you will need to read all the 'space' in the array to create parity.

the 'total sized' is based on your parity disk size multiplied by how many DRU you have.

Offline erfa

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Re: Verify & Sync task vs Create Parity task
« Reply #29 on: November 10, 2013, 03:42:26 pm »
You are creating parity for the disk/volume, not the data, hence disk full or empty, it will take the same time. Creating initial parity is the same for any form of RAID, you will need to read all the 'space' in the array to create parity.

the 'total sized' is based on your parity disk size multiplied by how many DRU you have.

Ah, I see. Thanks for the quick and precise answer! My ignorance on the matter is totally at fault :)

It was mentioned in this thread that the Verify & Sync task was faster at creating the initial parity, so I decided to try it out just for fun. I've added a screenshot of the result in case anyone is interested to compare with the previous one, it's exactly the same setup, the only difference is the task I chose (Verify&Sync vs Create Parity). As you can see it took 5 hours and 50 minutes to do Verify & Sync, compared to 11 hours with the Create Parity task. Since it's such a big difference, I'm left wondering if it's safe to continue using this raid or if I should delete it and create a new one using the Create Parity task. Any thoughts?