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<DIV name="wrteplaceholder">I have performed an experiment to get some idea about the overhead of drbd when its partner (the secondary node) is down.</DIV>
<DIV name="wrteplaceholder">I am using version 0.6.12 of drbd.</DIV>
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<DIV name="wrteplaceholder">The drbd has been in CState of WFConnection.</DIV>
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<DIV name="wrteplaceholder">I have performed a certain operation on the disk and it tool about 5.5 minutes when drbd was loaded and "owned" the disk on which the operation was performed. The operation involved tar and gzip.</DIV>
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<DIV name="wrteplaceholder">I then took drbd down and mounted the partitions drbd "owns" directly. I retried the operation and it took 4.5 minutes.</DIV>
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<DIV name="wrteplaceholder">There was an additional factor that the disk drbd "owns" contains the file system of a number of remote machines. These machines were idle at the time of the experiment.</DIV>
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<DIV name="wrteplaceholder">I looked at the code and it seemed to me like the overhead of drbd when the secondary node is down (and CState < Connected) is pretty small. Yet, the times I measured with this experiment show about 25% overhead of drbd.</DIV>
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<DIV name="wrteplaceholder">Do these results look like the ones you got in your experiments? Is this level of overhead reasonable?</DIV>
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<DIV name="wrteplaceholder">Thanks,</DIV>
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<DIV name="wrteplaceholder">Doron Zifrony</DIV>
<DIV name="wrteplaceholder">BladeFusion Technologies</DIV>
<DIV name="wrteplaceholder"><A href="mailto:dhz_bf@walla.co.il">dhz_bf@walla.co.il</A></DIV>
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