Clustrix recommends using a separate volume to store the ClustrixDB logs as opposed to using the same volume as the database data. This prevents having the database and the logs compete for storage space and IO. With AWS, it is easy to add a small EBS volume to handle the logs. Here is how to proceed using the AWS console and ssh access to each ClustrixDB node:
In the AWS console EC2> Volumes, select "Create Volume", and use the settings below:
Click Create. The volume will take a minute before it is available. Create a volume for each ClustrixDB node.
Once ready, you can attach the volume to your ClustrixDB instance:
Once every node has an EBS volume attached, it needs to be set up on each node individually.
Find the EBS volume. Below we are using an m3.xl instance with 2 ephemeral disks (xvdb and xvdc) that are in a raid0 (md0) used as a data volume.
$ cat /proc/partitions major minor #blocks name 202 0 8389632 xvda 202 1 8389600 xvda1 202 16 39313408 xvdb 202 32 39313408 xvdc 9 0 78561280 md0 202 80 52428800 xvdf <== this is the EBS volume |
Stop the database (this will stop the database on the node, and if clustered, on every node of the cluster).
$ clx dbstop |
Format the volume with ext4.
$ mkfs -t ext4 /dev/xvdf |
Create mount point, label the volume, update fstab, and mount the volume.
$ mkdir -p /var/log/clustrix $ e2label /dev/xvdf CLUSTRIX-LOG $ echo 'LABEL=CLUSTRIX-LOG /var/log/clustrix ext4 defaults,noatime,nodiratime 0 2'>> /etc/fstab $ mount -a |
Move the old log directory to the new one.
$ mv /data/clustrix/log/* /var/log/clustrix/. |
Create a symlink to the old directory (avoids config changes).
$ rm -rf /data/clustrix/log $ ln -s /var/log/clustrix/ /data/clustrix/log |
Check that everything worked.
$ df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda1 7.8G 1.5G 5.9G 21% / /dev/md0 74G 2.0G 68G 3% /data/clustrix /dev/xvdf 50G 53M 47G 1% /var/log/clustrix $ ls -l /data/clustrix/log lrwxrwxrwx. 1 root root 11 Aug 7 15:04 /data/clustrix/log -> /var/log/clustrix/ |
Proceed with step 3 through 6 on all the other ClustrixDB nodes.
Start the database.
$ clx dbstart |