The default values for the Maximum Number of blobs per Centera Clip and Maximum Number of KBytes per Centera Clip settings are 1 blob per clip and 1,048,576 KB (1 GB) per Centera clip, respectively. As a general rule, you do not need to change these default values, providing the Centera can keep pace with the CMS when storing data (to check this, you need to monitor the size of the blob queue table in the CMS database). If this is so, there is little advantage in increasing the clip size to achieve faster Centera storage rates.
However, a very fast CMS (for example, a multi CPU, 2 GHz machine) will get better Centera performance by putting more than 10MB in a single Centera clip, so you may want to experiment adjusting the clip size in this situation. Tuning these clip settings for optimum performance also depends on network bandwidth. There is less drop-off in the storage rate for larger Centera clip sizes if you have a Gigabit Ethernet NIC in the CMS. Again, you may need to experiment to find the optimum clip size.
In some circumstances the utilization of all the storage capacity on a Centera Node is limited by the maximum number of objects that can be stored. Generation 3 Centera hardware can store 50 M objects per node. This count includes all types of Centera object, for example CDF, blobs, mirrored copies, and parity fragments. If content is mirrored, then four Centera objects are stored per clip, that is, two CDFs (Clip Definition Files) and two blob files. As a general rule, you should ensure that at least 100 KB is stored in each clip when using mirrored content protection and at least 500 KB when using parity content protection.
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