e200i on Raid 5 logical drive Parity Initialization Status at 0% (4962 Views)
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Occasional Contributor
gpm25
Posts: 4
Registered: ‎02-24-2013
Message 1 of 9 (4,962 Views)
Accepted Solution

e200i on Raid 5 logical drive Parity Initialization Status at 0%

Hi there,

 

I have a HP ML350 G5 where we have replaced a failing HD in a Raid 5 array of 3 disks, the replacement drive has synchronised but in ACU it still shows a information alert for the Parity Initialization Status (currently at 0% and has been for the last 4 days since the drive was changed).

 

If I view the Information Status Messages I get a Code 785; Background parity initialization is currently queued or in progress on Logical Drive 1 (136.7 GB, RAID 5). If background parity initialization is queued, it will start when I/O is performed on the drive. When background parity initialization completes, the performance of the logical drive will improve. 

 

I need to change another drive soon as it is displaying F155: The read/write hard error rate recorded in the monitor and performance log is above the acceptable threshold. 

 

However I daren't change another drive until the parity sync is complete, does anyone have any thoughts as to futher actoin I should take?

 

Thanks in advance

Valued Contributor
xmate
Posts: 48
Registered: ‎02-19-2013
Message 2 of 9 (4,938 Views)

Re: e200i on Raid 5 logical drive Parity Initialization Status at 0%

[ Edited ]

Parity initialization is a long process - it can take from hours to weeks to complete.

Your data protection doesn't depent on it.

Initializing the parity takes place whenever the controller is NOT busy.

 

You can:

Update controller firmware

Update drives firmware

Update os controller driver

Replace HDD drive that report read/write hard error rate and wait for rebuild.

 

Finally the error should disappear.

 

Technology overview:

 

Parity initialization is a process commonly ran whan you create a logical drive.

For example you create RAID5 or RAID6. And you can use it immediatly. While the parity initialization processstill running. The storage volume has full fault tolerance.

After parity initialization is complete, writes to a RAID 5 or RAID 6 logical drive are typically faster because the controller does not read the entire stripe to update the parity data. Since the controller knows that the parity data is consistent with all the member drives in the stripe, the controller needs to read from only two disk drives during a RAID 5 write or three disk drives for a RAID 6 write to compute the parity data, regardless of array size.

 

For example you have 8 drives in RAID5. And a lot of free space (or onwritten stripes). As you know you have 7 data blocks and 1 parity block in the stripe. Before any data is written to the stripe this blocks contain unknown data. And parity block doesn't contain valid parity. So when you make a write to one block the controller have to read all the other blocks, calculate parity and write it to the parity block. (6 read operations, 1 data block write operation and 1 parity write operation = 8 operations). After Parity initialization the valid parity is in the parity block. So for each write operation controller makes 1 read operation for data block, 1 read for parity block, 1 write for data-block and 1 write for new parity = 4 operations.

 

Parity initialization enables advanced performance techniques.

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HP Pro
Renjiv
Posts: 112
Registered: ‎01-02-2012
Message 3 of 9 (4,937 Views)

Re: e200i on Raid 5 logical drive Parity Initialization Status at 0%

Hi,

 

This issue will occur due to Smart Array E200i controler driver, firmware evrsion. Or due to ADCU or ACU versions.

 

Smart Array Controller: The Consolidated Error Report in ADU reads Background parity initialization is currently queued or in progress on this logical drive. If background parity initialization is queued, it will start when I/O is performed on the drive. When background parity initialization completes, the performance of the logical drive will improve.

 

Solution:

 

1. Updated ADU(Array diagnostics Utility) and ACU to the latest.

 

2. Updated the controller driver, firmware and the HDD Firmware to the latest.

 

3. Confirm that there are no errors with the HDD (read and write).

 

4. Change the Rebuild Priority to High in ACU.

 

5. Once it is updated wait for an hour or two and generate the latest ADU report

 

If the issue persists, restart the server and generate latest ADU report and see if the Initialization Percentage is started.

 

If it is not started and Initilization shows 0%(0x00)  in  ADU, then follow the below steps.

 

1. Change the Cache settings to 75% write and 25% read, and then see if the initialization percentage for parity starts.
2. Take a new ADU report and check for the error message.

 

After following the 1st and 2nd step the initialization stats which means the issue is resolved.

 

Once this issue is resolved, you may replace the another hard drive.

 

I hope the info will help you.

 

Regards,

 

Renji V

 

I am an HP employee.

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Valued Contributor
xmate
Posts: 48
Registered: ‎02-19-2013
Message 4 of 9 (4,932 Views)

Re: e200i on Raid 5 logical drive Parity Initialization Status at 0%

[ Edited ]

Renjiv,

notice to your

4. Change the Rebuild Priority to High in ACU.

 Since the RAID rebuild already completed and parity initialization runs when there is no activity on controller - the rebuild priority setting doesn't affect parity initialization.

 

Instead you can try to set surface scan delay time to 1 second (valid time is from 1 sec to 30 sec). 

Because the setting for the surface scan delay determines the time interval for which a controller must be inactive before a surface scan analysis is started on the physical drives that are connected to it.  Surface scan analysis is an automatic background process that ensures that you can recover data if a drive failure occurs. The scanning process checks physical drives in fault-tolerant logical drives for bad sectors, and in RAID 5 or RAID 6 (ADG) configurations, it also verifies the consistency of parity data.

 

RAID levels that use parity (RAID 5, RAID 6 (ADG), RAID 50, and RAID 60) require that the parity blocks be
initialized to valid values. Valid parity data is required to enable enhanced data protection through
background surface scan analysis and higher performance write operations.

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HP Pro
Renjiv
Posts: 112
Registered: ‎01-02-2012
Message 5 of 9 (4,927 Views)

Re: iii on Raid 5 logical drive Parity Initialization Status at 0%

Hi xmate,

 

Thanks for the update and good to know more about surface scan delay. Yes, we can set surface scan delay time instead of rebuild priority.

 

As he has to replace one more drive, rebuild priority will help.

 

Previously, the same issue has occurred for E200i and performing the above steps resolved the issue. 

 

Lets wait for the update in this scenario.

 

I am an HP employee.

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Valued Contributor
xmate
Posts: 48
Registered: ‎02-19-2013
Message 6 of 9 (4,922 Views)

Re: iii on Raid 5 logical drive Parity Initialization Status at 0%

It's really interesting. Is there any explanation how changing cache settings to 75-25 affects parity initialization? It sounds really strange but if it works - I'll try to remember.
Thank you, Renjiv
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Occasional Contributor
gpm25
Posts: 4
Registered: ‎02-24-2013
Message 7 of 9 (4,905 Views)

Re: e200i on Raid 5 logical drive Parity Initialization Status at 0%

Thanks for that, as all drivers & ACU ADU ver were at the latest (although I did update HD firmware to HPD3), I didn change the Rebuild priority to High and overnight it has completed. Appreciate everyones comments.
Occasional Contributor
gpm25
Posts: 4
Registered: ‎02-24-2013
Message 8 of 9 (4,905 Views)

Re: e200i on Raid 5 logical drive Parity Initialization Status at 0%

Interesting I'll remember that for the future.
Occasional Contributor
gpm25
Posts: 4
Registered: ‎02-24-2013
Message 9 of 9 (4,905 Views)

Re: iii on Raid 5 logical drive Parity Initialization Status at 0%

Thanks guys, I'll insert the other new drive tomorrow and see how the changes affect rebuild & parity sync.
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