AFAIK, setting gc_grace_period to 0 shouldn't cause this issue. In fact, that what I'm using now in a single node environment like yours.
However, I'm using 0.7.2 with some patches. If you are still using 0.7.0, most likely you got hit with this bug. You might want to patch it or upgrade to latest release. https://issues.apache.org/jira/browse/CASSANDRA-2059 Regards, <https://issues.apache.org/jira/browse/CASSANDRA-2059> Chen Senior Developer, EvidentSoftware(Leaders in Monitoring of NoSQL & JAVA ) http://www.evidentsoftware.com On Mon, Mar 28, 2011 at 11:04 AM, Roberto Bentivoglio < roberto.bentivog...@gmail.com> wrote: > Hi Chen, > we've set the gc grace period of the column families to 0 as suggest in a > single node enviroment. > Can this setting cause the problem? I don't think so... > > Thanks, > Roberto > > On 28 March 2011 16:54, Ching-Cheng Chen <cc...@evidentsoftware.com>wrote: > >> tombstones removal also depends on your gc grace period setting. >> >> If you are pretty sure that you have proper gc grace period set and still >> on 0.7.0, then probably related to this bug. >> >> https://issues.apache.org/jira/browse/CASSANDRA-2059 >> >> Regards, >> >> <https://issues.apache.org/jira/browse/CASSANDRA-2059> >> >> Chen >> >> Senior Developer, EvidentSoftware(Leaders in Monitoring of NoSQL & JAVA ) >> >> http://www.evidentsoftware.com >> >> On Mon, Mar 28, 2011 at 10:40 AM, Roberto Bentivoglio < >> roberto.bentivog...@gmail.com> wrote: >> >>> Hi all, >>> we're working on a Cassandra 0.7.0 production enviroment with a store of >>> data near to 500 GB. >>> We need to periodically remove the tombstones from deleted/expired data >>> performing a major compaction operation through nodetool. >>> After invoking the compaction on a single column family we can see from >>> JConsole that the LiveSSTableCount is going from 15 to 3 while the >>> LiveDiskSpaceUsed is going from 90GB to 50GB. >>> The problem now is that the space on the file system is been taken from >>> Cassandra (I assumed from the old SSTable) and it isn't freed. We have tried >>> to perform a full GC from the JConsole as described in >>> http://wiki.apache.org/cassandra/MemtableSSTable without any success. >>> The space is freed only after a database restart. >>> >>> How can we free this disk space without restart the db? >>> >>> Thanks you very much, >>> Roberto Bentivoglio >>> >> >> >