VIOC_RESET, TOOLS, Reset Virtual I/O Cache counters The Virtual I/O Cache (VIOC) is a clusterwide, file-oriented disk cache available to all supported configurations, from single-node systems to large mixed-interconnect VMScluster systems. Any base system can use VIOC, no additional license is required. There are applications that cause the VIOC counters to be skewed, resulting in an incorrect interpretation of the usefullness of the VIOC. By resetting the counters, the SHOW MEMORY/CACHE/FULL display depicts a more accurate use of the VIOC. The following discussion is relevant to the SHOW MEMORY/CACHE/FULL display: The BACKUP utility typically causes a large increase to the "Read IO Count" while incurring no read hits. Depending on the amount of data being backed up, the increase to "Read IO Count" can be drastic in a short span of time. Since the "Read Hit Rate" remains somewhat flat for this same period of time, the calculated "Hit%" will be skewed. The skewed values will remain until the system is rebooted, or until enough time and I/Os, with an equitable hit rate, occur. Typically, "IO Bypassing Cache" will increase in proportion to "Read IO Count". Counters reset by this program: CACHE$GL_VREAD, the Read IO counter CACHE$GL_READHIT, the Read Hit counter CACHE$GL_VWRITE, the Write IO counter CACHE$GL_RRNDMOD, Read IO bypassing VIOC due to function CACHE$GL_RRNDSIZ, Read IO bypassing VIOC due to size CACHE$GL_WRNDMOD, Write IO bypassing VIOC due to function CACHE$GL_WRNDSIZ, Write IO bypassing VIOC due to size Submitted by: Reg Hunter, Customer Support Center, Colorado Springs