perfSONAR User Q&A and Other Discussion

[Andrew Lake <>]

Hi,

I’ve done the steps below a number of times to move cassandra to a different partition on the same host. Basically it’s just a move of the data directory to the new partition and creating a symlink from the old location to the new location. It has the advantage that you don't have to update any config files and it seems to just work. Below is an example that moves the data to a directory called /data/cassandra, but it can be any location on the new partition:

/etc/init.d/cassandra stop

mv /var/lib/cassandra /data/cassandra

ln -s /data/cassandra /var/lib/cassandra

/etc/init.d/cassandra start

You probably don't need to worry about postgresql, cassandra is usually the primary disk user since it stores the data and postgresql is the much smaller metadata.   

Thanks,

Andy

On April 9, 2018 at 2:01:00 PM, Hyojoon Kim () wrote:

Hello, 

It seems my MA machine is running out of disk space, and “df -h” clearly shows that (root “/" is 99% full).

Filesystem            Size  Used Avail Use% Mounted on

lv_root                50G   46G  675M  99% /

lv_data               238G  4.5G  222G   2% /data

I have a more space in “/data”. So I am thinking of (1) migrating all existing data to this new location, and also (2) configure perfSONAR/esmond to store future data to this new location. For (1), I have found this link, and I will probably use instructions in “Migrating Data” to move existing data to some place in “/data” (http://docs.perfsonar.net/multi_ma_backups.html). 

However, I am not sure how to do (2). I have found some instructions for each Cassandra and PostgreSQL, but I’m not sure if this is the right way. Is there an esmond configuration I should touch instead? 

https://docs.datastax.com/en/cassandra/2.1/cassandra/configuration/configCassandra_yaml_r.html

https://www.digitalocean.com/community/tutorials/how-to-move-a-postgresql-data-directory-to-a-new-location-on-ubuntu-16-04

(btw, I cannot find "/etc/postgresql/9.5/main/postgresql.conf” in my MA machine.)

Thanks,

Joon