\n1. Physical Drive space<\/strong>
\nLet’s take for example 900GB FC drive. Inside 3PAR MC it will report as Total Capacity<\/em> of 819GB. On the other hand 900GB SSD will report Total Capacity<\/em> 852GB.
\nNote: I don’t have information (formula) on how Total Capacity<\/em> derived from capacity reported by HD manufactures.<\/p>\n
Now let’s take a look what is used within Total Capacity<\/em> You can view it by issuing showpd -space<\/strong> command. 2. CPG space<\/strong> In 3PAR MC you can view remaining free space: Estimated Free System Space<\/span> should give a good indication on how much “real” free space (after RAID parity) remains on your 3PAR for a given CPG.<\/p>\n Please remember with Thin Volumes you can over-provision space as 3PAR’s ASIC removes all “zeros” on the fly.<\/p>\n","protected":false},"excerpt":{"rendered":" Today browsing one of my favorite 3PAR related websites\u00a0(3parug.com) I came across topic asking for a “real” free space. I assume someone is trying to find out how more of the actual data he\/she can fit before running out of … Continue reading
\n![\"showpd_space\"](\"https:\/\/blog.gptnet.net\/wp-content\/uploads\/2015\/01\/showpd_space.png\")
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\n– Size – total size described above
\n– Volume – how much space is actually used by Volumes
\n– Spare – space used by spare chunklets
\n– Free – space available for Volumes
\nNow let’s look at MC:
\n![\"3par_pd\"](\"https:\/\/blog.gptnet.net\/wp-content\/uploads\/2015\/01\/3par_pd.png\")
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\nTotal Capacity = Size
\nFree Capacity = Free
\nAllocated Capacity = Volume + Spare<\/p>\n
\nIn order to “use” PD space described above you need to assign drive to one CPG. CPG creates underlaying RAID from chunklets (1GB in size). So for example CPG with 5 – Data 1 – Parity will consume 6 GB of Free Capacity<\/em> on physical drives for each 5GB of data.<\/p>\n
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