Patent ID: 7539892
Filing Date: 2009-05-26
Classification: G06F

Abstract:
1. A method for resynchronizing data during a recovery operation in a mirrored storage computing system in which the track size of data stored at a production site is different from the track size of data stored at an associated recovery site, the method comprising: reading a first out-of-sync (OOS) bitmap from the production site, the first OOS bitmap identifying tracks stored at the production site which were written to during a failure at the production site; storing the first OOS bitmap in a buffer having a predetermined size; determining the track size of data stored at the production site relative to the track size of data stored at the recovery site; converting the first OOS bitmap into a modified first OOS bitmap in which track identities correspond to track identities of tracks stored at the recovery site; merging the modified first OOS bitmap into a second OOS bitmap identifying tracks stored at the recovery site which were written to during the failure at the production site, whereby a modified second OOS bitmap is generated identifying all tracks to be restored at the production site; and transferring from the recovery site to the production site those tracks identified by the modified second OOS bitmap; wherein: