How to reclaim the disk space consumed by the etcdserver's DB files
Log into any master node, and execute the following command. When it's done, copy the snapshot.db file to a safe place.
$ /var/vcap/jobs/etcd/bin/etcdctl snapshot save snapshot.db |
etcd adopts MVCC mechanism to manage the keyspace. It actually never removes data, instead it always appends new data even for the case of deleting a key/value. So we can compact the history to avoid eventual storage space exhaustion. Please log into any master node and execute the following commands. Note that you only need to execute the commands one time on one master node.
Firstly, execute command below to get the latest revision,
# /var/vcap/jobs/etcd/bin/etcdctl endpoint status -w json | egrep -o '"revision":[0-9]*' | egrep -o '[0-9].*' |
Secondly, execute command below to compact away old revisions,
# /var/vcap/jobs/etcd/bin/etcdctl compact 2638877 # 2638877 is the revision returned by previous command |
Please note that you need to execute the following commands on each master node.
## Step 1 : Stop etcd # monit stop etcd ## Step 2 : Backup the /var/vcap/store/etcd/member # cp -r /var/vcap/store/etcd/member path-to-somewhere ## Step 3 : Defragment # /var/vcap/jobs/etcd/bin/etcdctl defrag --data-dir /var/vcap/store/etcd ## Step 4 : Change ownership # chown vcap:vcap /var/vcap/store/etcd/member/snap/db ## Step 5 : Start etcd # monit start etcd |
Note that etcd 3.5 (TKGI 1.13) provides a new tool etcdutl, and we need to use etcdutl at step 3, but unfortunately we do not deploy the the binary etcdutl for now. We will get it included soon in TKGI 1.14.
Log into any master node, and execute commands below:
# Step 1 : List all alarms # /var/vcap/jobs/etcd/bin/etcdctl alarm list # Step 2 : Disarms all alarms # /var/vcap/jobs/etcd/bin/etcdctl alarm disarm |