misdell
1 Copper

Perc 6i RAID 5 question

We are trying to rebuild a RAID  5 array but our virtual disk is offline resulting in three missing drives out of six that made up the array.  We initially had one drive that was degraded but upon further inspection realized our virtual disk was offline.  We have since cleared the foreign disk to try and automatically rebuild the array but have had no success and their is currently no option to rebuild.

Is it possible to rebuild a RAID 5 array when your virtual disks are offline and the controller is only reporting 3 out of the 6 drives as online?  Thank you for your help!

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3 Replies
Moderator
Moderator

RE: Perc 6i RAID 5 question

Misdell,

Since the original drive failure, do you know if the other 2 drives failed simultaneously at a later point? If so then what we can do is retag the Virtual Disk from the Raid Controller.

Now it is strongly advised to verify you have a complete, current backup of your data before performing the following steps.

A retag is essentially deleting and then recreating the Virtual Disk WITHOUT initializing the VD after you recreate it, as that deletes the drives contents. When you have a retag you would need to have all the drives present in the server to recreate the VD.  Once you recreate the Virtual Disk you would then power down the server and remove the ORIGINAL failed drive, once the drive is removed then boot the system. If you make it to the OS then simply insert the original failed drive and see if it rebuilds.

Now just to let you know. Performing a retag may result in the loss of all data on the VD. Caution should be used to ensure that NO changes in the VD are made when performing a retag, including Drives, Drive Order, Stripe Size, Cache Policies, etc. Again after creation do NOT initialize the Virtual Disk, or the data will be lost.

Let me know if this clarifies things, if you are unsure about the retag or anything else then let me know BEFORE attempting.

Chris Hawk

Dell | Social Outreach Services - Enterprise
Get Support on Twitter @DellCaresPro 
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misdell
1 Copper

RE: Perc 6i RAID 5 question

Hi Chris,  

Thank you for the quick reply.  The only thing we know is that one of the drives is definitely in a degraded state and three show up as online and three show up as ready.  We are not sure which of the five drives failed to break the array but we assume it happened on connector 0 where all the missing drives are showing up.  Currently only one drive shows up as a predicted failure disk.

With regard to the retag process, do we have to have the exact same RAID config set up for the retag?  Since we cannot boot to the OS, is there a way to grab the config from the log files of the controller?  I was able to open the log file through an Open Manage live disk.

Thank you again for your help.

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Moderator
Moderator

RE: Perc 6i RAID 5 question

The raid configuration will have to match the previous configuration, or the data can be corrupted. So you want to try to be accurate.

Chris Hawk

Dell | Social Outreach Services - Enterprise
Get Support on Twitter @DellCaresPro 
Download the Dell Quick Resource Locator app today to access PowerEdge support content on your mobile device! (iOS, Android, Windows)

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