为提高效率，提问时请提供以下信息，问题描述清晰可优先响应。
- 【TiDB 版本】：V3.0.3
- 【问题描述】：dm版本为V1.0.3
第一步：修改"dm部署目录/conf/dm-worker.toml"配置文件中的[purge]配置组三个参数，如下 第二步：执行 ansible-playbook rolling_update.yml --tags=dm-worker命令，以重启dm-work组件，以便修改的配置参数生效 第三步：发现dm任务出现报错 fail to initial unit Sync of subtask test_order_dm : no valid relay sub directory exists 第四步：第一步时只是修改了配置的值，并未修改其他任何文件和目录。后面使用resume-task命令救火，发现没起效果，任务依然同样报错
[purge]
interval = 3600
expires = 24
remain-space = 15
“msg”: “[code=28005:class=relay-event-lib:scope=internal:level=high] fail to initial unit Sync of subtask test_order_dm : no valid relay sub directory exists\ngithub.com/pingcap/dm/pkg/terror.(*Error).Generate\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/pkg/terror/terror.go:232\ngithub.com/pingcap/dm/syncer.(*Syncer).setInitActiveRelayLog\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/relay.go:47\ngithub.com/pingcap/dm/syncer.(*Syncer).Init\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/syncer/syncer.go:409\ngithub.com/pingcap/dm/dm/worker.(*SubTask).Init\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/dm/worker/subtask.go:129\ngithub.com/pingcap/dm/dm/worker.(*SubTask).Run\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/dm/worker/subtask.go:172\ngithub.com/pingcap/dm/dm/worker.(*SubTask).Resume\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/dm/worker/subtask.go:415\ngithub.com/pingcap/dm/dm/worker.(*Worker).handleTask\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/dm/worker/worker.go:880\ngithub.com/pingcap/dm/dm/worker.(*Worker).Start.func1\ \t/home/jenkins/agent/workspace/build_dm_master/go/src/github.com/pingcap/dm/dm/worker/worker.go:178\ runtime.goexit\ \t/usr/local/go/src/runtime/asm_amd64.s:1357”,
1：请问是什么原因引起的呢 ？难道是修改配置的流程不对吗？ 当前这种错误该如何解决呢？
2：请问expires和remain-space参数可以在任务初始化时就进行修改吗？ 该如何修改呢？
谢谢
