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raid 1 initialization time

hello i'm setting up a RAID 1 configuration on my POWEREDGE T110 ii server , With PERC H200a controller , i have 4 * 1 TB disk , i did 1 raid volume and put 2 hot spares disks ,


it shows that there is 47% initialized ! it took 24 hours now ... is it normal ?

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Re: raid 1 initialization time

Yes, a full initialization can take a long time. It may also be that the status is not updating in the controller BIOS. If the percentage has not changed in a long time then I would suspect it is not updating properly with the correct percentage.

A full initialization writes zeros to every virtual disk member. How long it takes will depend on all of the hardware in the RAID chain. The speed of the controller, speed of the drives, and number of drives will all affect the amount of time required. The H200 is a low/mid-range storage controller that does not have write cache. Since it cannot queue requests in write cache it will wait to receive confirmation of the last command before sending the next. This will keep all of the drives from writing near their maximum capabilities.


If these are 7200 RPM SATA drives then their max write speed is somewhere around 150MB/s. Based on the times you are seeing, it will take ~48 hours to complete the initialization. 2000/48=41.7. The drives appear to be writing at about 41.7MB/hour. That breaks down to about 11.57KB/s. That is not normal, it is abnormally slow. I would suspect that there is either information I am unaware of or there is an issue.

The most likely issue would be a communication problem. If the controller and drives are having issues communicating then they will send each request multiple times. Communication is a firmware issue, if you are using unsupported drives that may be the problem. Our PERCs are designed to work with certified drives that run our firmware. You can try updating the firmware on the PERC and drives to see if you can find a combination that works well.

Daniel Mysinger
Dell EMC, Enterprise Engineer

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