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VCC_MAX_IO_SIZE is a system parameter that controls the maximum size of I/O that can be cached by the extended file cache. It specifies the size in blocks. By default, the size is 127 blocks. Changing the value of VCC_MAX_IO_SIZE affects reads and writes to volumes currently mounted on the local node, as well as reads and writes to volumes mounted in the future. If VCC_MAX_IO_SIZE is 0, the extended file cache on the local node cannot cache any reads or writes. However, the system is not prevented from reserving memory for the extended file cache during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved memory registry. VCC_MAX_IO_SIZE is a DYNAMIC parameter. This parameter is available on Alpha and Integrity servers only.