Akhil, I agree with you that the node still has unwanted data, but why it has 
more data than before cleaning up?

More background:
Before cleaning up, the node has 790GB data. After cleaning up, I assume it 
should has less data. But in fact it has 1000GB data which is larger than I 
Cassandra daemon crashed and left the files with the name with "tmp-" prefix in 
the data directory which indicate the cleaning up task was not complete.

From: Akhil Mehra
Date: 2017-06-19 15:17
To: wxn...@zjqunshuo.com
CC: user
Subject: Re: Cleaning up related issue
When you add a new node into the cluster data is streamed for all the old nodes 
into the new node added. The new node is now responsible for data previously 
stored in the old node.
The clean up process removes unwanted data after adding a new node to the 
In your case clean up failed on this node. 
I think this node still has unwanted data that has not been cleaned up.
> On 19/06/2017, at 7:00 PM, wxn...@zjqunshuo.com wrote:
> Thanks for the quick response. It's the existing node where the cleanup 
> failed. It has a larger volume than other nodes.
> From: Akhil Mehra
> Date: 2017-06-19 14:56
> To: wxn002
> CC: user
> Subject: Re: Cleaning up related issue
> Is the node with the large volume a new node or an existing node. If it is an 
> existing node is this the one where the node tool cleanup failed.
> Cheers,
> Akhil
>> On 19/06/2017, at 6:40 PM, wxn...@zjqunshuo.com wrote:
>> Hi,
>> After adding a new node, I started cleaning up task to remove the old data 
>> on the other 4 nodes. All went well except one node. The cleanup takes hours 
>> and the Cassandra daemon crashed in the third node. I checked the node and 
>> found the crash was because of OOM. The Cassandra data volume has zero space 
>> left. I removed the temporary files which I believe created during the 
>> cleaning up process and started Cassanndra. 
>> The node joined the cluster successfully, but one thing I found. From the 
>> "nodetool status" output, the node takes much data than other nodes. Nomally 
>> the load should be 700GB. But actually it's 1000GB. Why it is larger? Please 
>> see the output below. 
>> UN   705.98 GB  256          40.4%             
>> 9180b7c9-fa0b-4bbe-bf62-64a599c01e58  rack1
>> UN  691.07 GB  256          39.9%             
>> e24d13e2-96cb-4e8c-9d94-22498ad67c85  rack1
>> UN   623.73 GB  256          39.3%             
>> 385ad28c-0f3f-415f-9e0a-7fe8bef97e17  rack1
>> UN   779.38 GB  256          40.1%             
>> 46f37f06-9c45-492d-bd25-6fef7f926e38  rack1
>> UN  1022.7 GB  256          40.3%             
>> a31b6088-0cb2-40b4-ac22-aec718dbd035  rack1
>> Cheers,
>> -Simon

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