Lines Matching refs:MD

29 unclean shutdown. We call an array degraded if it has inconsistent data. MD
36 two-step write will guarantee MD can recover correct data after unclean
39 In write-through mode, MD reports IO completion to upper layer (usually
53 write. For non-full-stripe writes, MD must read old data before the new parity
61 In write-back mode, MD reports IO completion to upper layer (usually
66 In write-back mode, MD also caches data in memory. The memory cache includes
85 checksum is an optimization because MD can write meta and data freely without
86 worry about the order. MD superblock has a field pointed to the valid meta data
90 order in which MD writes data to cache disk and RAID disks. Specifically, in
91 write-through mode, MD calculates parity for IO data, writes both IO data and
96 In write-back mode, MD writes IO data to the log and reports IO completion. The
98 memory cache. If some conditions are met, MD will flush the data to RAID disks.
99 MD will calculate parity for the data and write parity into the log. After this
100 is finished, MD will write both data and parity into RAID disks, then MD can
105 After an unclean shutdown, MD does recovery. MD reads all meta data and data
107 data and data. If MD finds a stripe with data and valid parities (1 parity for
108 raid4/5 and 2 for raid6), MD will write the data and parities to RAID disks. If
110 they are discarded too. MD then loads valid data and writes them to RAID disks