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https://issues.apache.org/jira/browse/CASSANDRA-6179?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13801347#comment-13801347
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J. Ryan Earl edited comment on CASSANDRA-6179 at 10/22/13 12:19 AM:
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Requested dump.txt attached.


was (Author: jre):
Request dump.txt attached.

> "Load" calculated in "nodetool info" is strange/inaccurate in JBOD setups
> -------------------------------------------------------------------------
>
>                 Key: CASSANDRA-6179
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6179
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: JBOD layouts
>            Reporter: J. Ryan Earl
>            Assignee: Mikhail Stepura
>         Attachments: dump.txt
>
>
> We recently noticed that the storage capacity on Cassandra nodes using JBOD 
> layout was returning what looks close to the average data volume size, 
> instead of the sum of all JBOD data volumes.  It's not exactly an average and 
> I haven't had time to dig into the code to see what it's really doing, it's 
> like some sort of sample of the JBOD volumes sizes.
> So looking at the JBOD volumes we see:
> {noformat}
> [jre@cassandra2 ~]$ df -h
> Filesystem            Size  Used Avail Use% Mounted on
> [...]
> /dev/sdc1             1.1T  9.4G  1.1T   1% /data/1
> /dev/sdd1             1.1T  9.2G  1.1T   1% /data/2
> /dev/sde1             1.1T   11G  1.1T   1% /data/3
> /dev/sdf1             1.1T   11G  1.1T   1% /data/4
> /dev/sdg1             1.1T  9.2G  1.1T   1% /data/5
> /dev/sdh1             1.1T   11G  1.1T   1% /data/6
> /dev/sdi1             1.1T  9.8G  1.1T   1% /data/7
> {noformat}
> Looking at 'nodetool info' we see:
> {noformat}
> [jre@cassandra2 ~]$ nodetool info
> Token            : (invoke with -T/--tokens to see all 256 tokens)
> ID               : 631f0be3-ce52-4eb9-b48b-069fbfdf0a97
> Gossip active    : true
> Thrift active    : true
> Native Transport active: true
> Load             : 10.57 GB
> {noformat}
> So there are 7 disks in a JBOD configuration in this example, the sum should 
> be closer to 70G for each node.  Maybe we're misinterpreting what this value 
> should be, but things like OpsCenter appear to use this "load" value as the 
> size of data on the local node, which I expect to be the sum of JBOD volumes.



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