I would start by disconnecting the system from all external resources like the network. Once you wipe data it may pull new data if it is still connected, like DHCP network addresses. The T110 has limited features with the BMC, but I would go into the BMC and make sure all of the logs are deleted. You can use the clear NVRAM jumper to wipe the BIOS settings and configuration. That should get rid of any asset names, IP addresses, or any other personal information that might be stored in the BMC or BIOS. You can find more information in the manual on the system support page.
I can't think of a way to keep the OS intact. If you have data handling policies then you should follow them. If you are just wanting to wipe the drives and have no specific procedures you must follow then writing zeroes is a good way. If you are using one of our PERCs then you should be able to perform a full initialization. If you create a new virtual disk across the drives and choose the option for full initialization it will write zeroes across the drives. It is best to create an unlike array when doing this for the purpose of data destruction. For instance, if there is currently a RAID 5 then create a RAID 0 or anything other than a RAID 5. Some of our controllers force a full initialization on virtual disk creation, it is optional on some. You can find out more about your controller in the manual.
Dell EMC, Enterprise Engineer
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