In the processes of either decompressing or truncating compressed files, some data blocks may be de-allocated. A problem has been identified in which the data may be recalled from LROC devices if the data for these de-allocated blocks was stored into LROC devices before de-allocation. As a result of the data being recalled from the LROC devices, data in memory may become corrupted, with potential for the data on disks to also become corrupted. Note that many types of file modifications (e.g., write, punch hole) of the data of compressed files could trigger an on-the-fly transparent uncompression operation, including GPFS's command line or policy interfaces (e.g., mmrestripefs -z, mmchattr --compression no ).
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