Kubernetes 1.18.4，iSCSI

Question

我在连接Kubernetes的每个iSCSI的卷时遇到了问题。当我尝试从worker节点使用iscisiadm时，它工作了。这是我从kubectl description pod得到的。

Normal   Scheduled               <unknown>             default-scheduler        Successfully assigned default/iscsipd to k8s-worker-2
Normal   SuccessfulAttachVolume  4m2s                  attachdetach-controller  AttachVolume.Attach succeeded for volume "iscsipd-rw"
Warning  FailedMount             119s                  kubelet, k8s-worker-2    Unable to attach or mount volumes: unmounted volumes=[iscsipd-rw], unattached volumes=[iscsipd-rw default-token-d5glz]: timed out waiting for the condition
Warning  FailedMount             105s (x9 over 3m54s)  kubelet, k8s-worker-2    MountVolume.WaitForAttach failed for volume "iscsipd-rw" : failed to get any path for iscsi disk, last err seen:iscsi: failed to attach disk: Error: iscsiadm: No records found(exit status 21)

我只是在使用来自kubernetes.io的iscsi.yaml文件！

---
apiVersion: v1
kind: Pod
metadata:
  name: iscsipd
spec:
  containers:
  - name: iscsipd-rw
    image: kubernetes/pause
    volumeMounts:
    - mountPath: "/mnt/iscsipd"
      name: iscsipd-rw
  volumes:
  - name: iscsipd-rw
    iscsi:
      targetPortal: 192.168.34.32:3260
      iqn: iqn.2020-07.int.example:sql
      lun: 0
      fsType: ext4
      readOnly: true

Open-iscsi安装在所有工作节点(仅其中两个)上。

● iscsid.service - iSCSI initiator daemon (iscsid)
   Loaded: loaded (/lib/systemd/system/iscsid.service; enabled; vendor preset: e
   Active: active (running) since Fri 2020-07-03 10:24:26 UTC; 4 days ago
     Docs: man:iscsid(8)
  Process: 20507 ExecStart=/sbin/iscsid (code=exited, status=0/SUCCESS)
  Process: 20497 ExecStartPre=/lib/open-iscsi/startup-checks.sh (code=exited, st
 Main PID: 20514 (iscsid)
    Tasks: 2 (limit: 4660)
   CGroup: /system.slice/iscsid.service
           ├─20509 /sbin/iscsid
           └─20514 /sbin/iscsid

ISCSI Target是在IBM Storwize V7000上创建的。没有CHAP。

我尝试从worker节点连接iscsiadm，它工作了。

sudo iscsiadm -m discovery -t sendtargets -p 192.168.34.32
192.168.34.32:3260,1 iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1
192.168.34.34:3260,1 iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1

sudo iscsiadm -m node --login
Logging in to [iface: default, target: iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1, portal: 192.168.34.32,3260] (multiple)
Logging in to [iface: default, target: iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1, portal: 192.168.34.34,3260] (multiple)
Login to [iface: default, target: iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1, portal: 192.168.34.32,3260] successful.
Login to [iface: default, target: iqn.1986-03.com.ibm:2145.hq-v7000.hq-v7000-rz1-c1, portal: 192.168.34.34,3260] successful.

Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 32768 bytes / 32768 bytes
Disklabel type: dos
Disk identifier: 0x5b3d0a3a

Device     Boot Start       End   Sectors  Size Id Type
/dev/sdb1        2048 209715199 209713152  100G 83 Linux

有没有人面临同样的问题？

Answer 1

记住不要对目标使用主机名。使用IP。由于某种原因，如果目标是一个主机名，它会抛出关于请求重复会话的错误。如果目标是一个IP，它就可以正常工作。我现在在不同的pod中安装了多个iSCSI目标，我绝对欣喜若狂。

您可能还会遇到iscsi目标的身份验证问题。

如果您尚未使用CHAP身份验证，则仍需禁用身份验证。例如，如果您使用targetcli，您可以运行以下命令来禁用它。

$ sudo targetcli
/> /iscsi/iqn.2003-01.org.xxxx/tpg1 set attribute authentication=0 # will disable auth
/> /iscsi/iqn.2003-01.org.xxxx/tpg1 set attribute generate_node_acls=1 # will force to use tpg1 auth mode by default

如果这对您没有帮助，请分享您的iscsi目标配置，或参考您遵循的指南。

重要的是检查您的所有节点是否都安装了open-iscsi-package。

看看：kubernetes-iSCSI，volume-failed-iscsi-disk，iscsi-into-container-fails。