Dell Unity: How to copy customer data back to system drives from the hotspare used in Traditional Pools. (Dell Correctable)

Summary: This article describes how to copy customer data back to system drives from the hotspare used in Traditional pools.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
Check out other resources

Instructions

When a system drive that is part of a traditional pool fails, only the user data is copied to an available hotspare.
When that system drive is later on replaced, the data does not copy back to the system drive.

After the faulted system drive has been replaced, the user data will not be copied back to the system drive. This is due to the Unity "Permanent Sparing" feature, where typically the replaced drive becomes the new hotspare. However, the replaced system drive cannot become a hotspare by rule, which can lead to a hotspare rule failure as there is one less hotspare available.

In order to resolve this situation, the user data has to be manually copied back to the system drive.
This can be done using the "svc_copyto" command.
Usage:

svc_copyto -sd <source drive> -dd <destination drive>

 

  • This service script is used to copy user data from one drive to another. It can only be used for system (vault) drives (slots 0-3) in traditional pools. When a drive fails, a hot spare is permanently swapped in. The user can use this command to move the data back to the original location when the faulted drive has been replaced.
  • This command can used in Normal Mode.
  • Depending on the array model, permissible destination drive values are:

               0_0_0, 0_0_1, 0_0_2, 0_0_3, or 9_0_0, 9_0_1, 9_0_2, 9_0_3, or 99_0_0, 99_0_1, 99_0_2, 99_0_3
 

From the Unity logs, find out which system drive failed.
/EMC/backend/log_shared/EMCSystemLogFile.log (or previous file based on date and time)
Then also find out which hotspare drive the data was copied to.
Next, issue the svc_copyto command, using the drive numbers found in the logs.
Below example shows drive 0-0-3 failed to drive 0-0-9.
After disk 0-0-3 is replaced and online, then issue:
    

  service@none spa:/#  svc_copyto -sd 0_0_9 -dd 0_0_3


Log examples:

"2022-10-10T19:45:25.952Z" "spa@CKM00184101111" "Kittyhawk_safe" "29643" "unix/spa/root" "WARN" "1:1684004" :: "Disk in slot 0_0_3 needs to be replaced, serial num:ABC123    " :: Category=System Component=sep TimeZone=UTC

"2022-10-10T19:45:30.177Z" "spb@CKM00184101111" "Kittyhawk_safe" "27846" "unix/spb/root" "INFO" "1:1680113" :: "Proactive spare swapped-in.Disk 0_0_9,serial num:ABC1234         is permanently replacing disk 0_0_3,serial num:W402LXKB    " :: Category=System Component=sep TimeZone=UTC

"2022-10-10T19:45:36.027Z" "spb@CKM00184101111" "Kittyhawk_safe" "27846" "unix/spb/root" "INFO" "1:1680103" :: "Copy from disk 0_0_3 to disk 0_0_9 started" :: Category=System Component=sep TimeZone=UTC

"2022-10-10T19:55:34.097Z" "spa@CKM00184101111" "Kittyhawk_safe" "29643" "unix/spa/root" "ERROR" "1:1678057" :: "Bus 0 Enclosure 0 Disk 3 taken offline. Replace the drive. SN:W402LXKB     TLA:005051632    Rev:TN0F (0x2770003) Reason:EOL set." :: Category=System Component=espkg TimeZone=UTC

 

If any further assistance is needed, call in to Dell technical support.

 

Additional Information

For Dell Unity traditional pool hotspare policy, see Dell Unity™ Family Configuring Pools documentation-  See the section titled, Introduction to pools -> Spare drive policy (physical deployment only):  https://www.dell.com/support/manuals/en-us/unity-all-flash-family/unity_p_pool_config/additional-resources?guid=guid-1ff33451-8726-4481-a2ca-7d71d61ffe7c&lang=en-us

Drive copy or rebuilds can be monitored using:
Article number 000022586 Dell Unity: How to monitor the rebuild progress after a disk failure or replacement (User Correctable)

Affected Products

Dell EMC Unity, Dell EMC Unity Family
Article Properties
Article Number: 000192478
Article Type: How To
Last Modified: 02 Sept 2025
Version:  4
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.