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From Peter Schuller <>
Subject Re: Defrag
Date Wed, 02 Mar 2011 22:51:26 GMT
> Are there any details on how much of an issue fragmentation is (with
> Cassandra ) ?
> With all the merging and deletes that happen with during compactions,
> how does the disk fragmentation look like over time ? Any thumb-rules
> on how frequently and how to defrag ?

Cassandra is about as friendly as it can be with respect to
fragmentation. All data is written sequentially and in bulk. Assuming
a modern file system, and assuming you don't run at 99% disk capacity
(which would explode in your face anyway), fragmentation should be a
non-issue. The only realistic circumstances where I would expect
fragmentation is if you run Cassandra on a file system that also does
something else that fragments the hell out of it.

/ Peter Schuller

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