{{Short description|Standard format for data in RAID}}
The [[Storage Networking Industry Association|SNIA]] Commoncommon [[RAID]] '''Diskdisk Datadata Formatformat''' ('''DDF''') defines a standard data structure describing how data is formatted across disks in a RAID group. The DDF structure allows a basic level of [[interoperability]] between different suppliers of RAID technology. The Commoncommon [[Redundant array of independent disks|RAID]] DDF structure benefits storage users by enabling in-place data migration or recovery after controller failure using systems from different vendors.<ref>{{cite web |url=http://www.snia.org/tech_activities/standards/curr_standards/ddf |publisher=Storage Networking Industry Association |title=Common RAID Disk Data Format (DDF) |website=SNIA.org }}</ref>
DDF is an external metadata format that is compatible with the mdraid subsystem in the Linux kernel. The [[mdadm]] command-line utility is a part of the mdraid subsystem.<ref>{{Cite web |title=Chapter 21. Managing RAID Red Hat Enterprise Linux 8 |url=https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/managing_storage_devices/managing-raid_managing-storage-devices |access-date=2023-01-06 |website=Red Hat Customer Portal |language=en}}</ref>
