Patent ID: 6230246
Filing Date: 2001-05-08
Classification: G06F

Abstract:
A computer system for non-intrusive copying of a distributed storage system, the computer system comprising:a plurality of storage devices for storing data, the plurality of storage devices forming a portion of a distributed storage system;a plurality of storage servers, individual ones of the plurality of storage servers connected to and operably associated with individual ones of the plurality of storage devices wherein a one-to-one relationship is established between each individual one of the plurality of storage devices and each individual one of the plurality of storage servers;a plurality of write-barrier indicator storage elements, each being configured to include at least one bit indicative of a write-barrier state or a no-write-barrier state and each individual ones of the plurality of write-barrier indicator storage elements being operably associated with individual ones of the plurality of storage devices and operably associated with individual ones of the plurality of storage servers wherein a one-to-one relationship is established between the individual ones of the plurality of storage devices and the individual ones of the plurality of write-barrier indicator storage elements; anda backup storage device connected to the plurality of storage devices, the back-up storage device for storing at least an indication of the data stored at the plurality of storage devices;wherein a first of the plurality of write-barrier indicator storage element is associated with a first of the plurality of storage devices and the first of the plurality of write-barrier indicator storage elements includes a bit indicating the write-barrier state thereby preventing writes to the first of the plurality of storage devices until the contents of the first of the plurality of storage devices have been replicated to the backup storage devices, the write-barrier state being established in association with a transfer of at least an indication of data stored at the first of the plurality of storage devices from the first of the plurality of storage devices to the back-up storage device; andwherein the ones of the plurality of write-barrier indicator storage elements other than the first of the plurality of write-barrier indicator storage elements each simultaneously include a bit indicating a no-write-barrier state for each of the operably associated individual ones of the plurality of storage devices, thereby permitting writes to the individual ones of the plurality of storage devices operably associated with the ones of the plurality of write-barrier indicator storage elements.