Storage

What should I do if an error occurs when I create a storage pool that uses an iSCSI shared file system?

Symptom

The "internal error Child process (/bin/mount -t ocfs2 /dev/disk/by-path/ip-192.168.10.1:3260-iscsi-iqn.2007-04.com.xxx:storware.target4-lun-0 /vms/target4) status unexpected: exit status 1" error message is displayed when a storage pool that uses an iSCSI shared file system is being created.

Condition

When creating a storage pool that uses an iSCSI shared file system for a host, CVM automatically requests non-exclusive read-write access to the storage target. This issue occurs if the host already has a session to the storage target with read-only access.

Solution

To resolve this issue:

1. Log in to the host by using SSH.

2. Execute the iscsiadm -m session command to view storage target sessions.

root@vmc-10:/vms/isos# iscsiadm -m session

tcp: [2] 192.168.10.1:3260,1 iqn.2007-04.com.xxx:storware.target4

tcp: [4] 192.168.10.1:3260,1 iqn.2007-04.com.xxx:storware.640f02.target3

3. Disconnect the session to the target. For example, to disconnect the session to Target iqn.2007-04.com.xxx:storware.target4, execute the following command:

root@vmc-10:/vms/isos# iscsiadm -m node -T iqn.2007-04.com.xxx:storware.target4 -u -p 192.168.10.1

Logging out of session [sid: 2, target: iqn.2007-04.com.xxx:storware.target4, portal: 192.168.10.1

4. On the iSCSI storage controller, detach the host from iqn.2007-04.com.xxx:storware.target4.

How do I avoid unexpected host reboots when I use the iSCSI storage controller to delete the logical resources in the storage target for a shared file system?

Symptom

Unexpected host reboots occur when logical resources are deleted from the storage target for a shared file system from the iSCSI storage controller.

Condition

If you delete logical resources from the target while the host is writing data to the target, the host will be unable to complete its write operation. To protect storage integrity and prevent storage corruption, the host will be automatically rebooted.

For example, host A uses shared file system target3, which is based on target3 on iSCSI storage, and target3 uses SAN-03 as the logical resource. When host A is using shared file system target3, the administrator deletes SAN-03 from the logical resources of target3 on the iSCSI storage manager. Then, VM vmc-6 on host A will fail to write data and host A will restart.

Restrictions and guidelines

Deleting logical resources from a storage target might cause serious service interruption. Before you delete logical resources from a target, you must make sure no hosts in CVM are using that target as a shared file system. If a host uses that target as a shared file system, you must take preventive action to minimize the impact of the deletion on services.

How to format the disk of a shared file system?

Symptom

The system displays that the storage pool has not been attached to any hosts or displays that the system is busy when the disk of a shared file system is re-formatted.

Condition

Disk formatting is available only for the shared file system that has been specified as the storage pool for a minimum of one host. In addition, the operation can be performed only when the storage pool is not active.

Solution

To resolve the disk reformatting failure that occurs because the storage pool is not attached to any hosts:

1. In the navigation tree, select a host from the host pool.

2. In the Storage tab of the host, add a host pool that uses the shared file system to the host, and suspend the storage pool.

3. Navigate to the host pool, click the tab for shared file system management, and then reformat the disk of the shared file system.

To resolve the disk reformatting failure that occurs because of a busy system:

1. Suspend the storage pool on each host that uses this storage pool.

2. Navigate to the host pool, click the tab for shared file system management, and then reformat the disk of the shared file system.

What should I do if CVM does not display the increase in storage capacity for a shared file system after its hardware storage is expanded?

Symptom

CVM does not display the increase in storage capacity for a shared file system after its hardware storage is expanded.

Solution

To resolve this issue, back up the files stored in the file system, and then use CVM to reformat the disk of the file system as follows:

1. Back up the files in the shared file system.

2. In the storage list of each host that has a storage pool using this file system, select the storage pool, delete all VM files, and then suspend the storage pool.

3. In the shared file system list of the host pool that contains the hosts, format the disk of the shared file system.

4. Copy the backup files back to the shared file system.

5. In the storage list of each host, start the storage pool.

What should I do if a storage pool that uses a shared file system becomes unavailable after an unexpected interruption of disk formatting for that shared file system?

Symptom

A storage pool that uses a shared file system becomes unavailable after an unexpected interruption of disk formatting for that shared file system.

Condition

To resolve this issue, reformat the disk for the shared file system.

Why does it take a long time for CVM to refresh status and volume information for a storage pool that provides Windows shared directory service for a host?

Symptom

It takes a long time for CVM to refresh status and volume information for a storage pool that provides Windows shared directory service for a host after a server shutdown, NIC down, or shared directory service disabled event.

Condition

This issue typically occurs the first time you view storage pool information after a server shutdown, NIC down, or shared directory service disabled event. Because of the underlying file sharing protocol limitation, it might take about 3 minutes to open the storage tab of the host and about 1 minute to display status and volume information for the storage pool.

The system display a file copying error when I download a storage volume

Symptom

The system display a file copying error when I download a large storage volume again before the previous download is complete.

Condition

This issue occurs when the system attempts to copy the source volume file to overwrite the existing destination file, which is still incomplete. The system displays the error message only for the second download operation even though both download operations are failed.

Solution

To resolve this issue, wait for a while before you download the storage volume again.

Why can't I start the storage pool for a host after I edit the LUN-host mapping on the storage device, and what should I do?

Condition

If you do not suspend or delete the storage pool from the host before you edit the LUN-host mapping, the storage device state in the host kernel changes when you edit the LUN-host mapping. The system cannot automatically process this state change, so the storage pool cannot be started for the host. If you forcibly start the storage pool for the host, data corruption might occur.

Solution

To resolve this issue:

1. Delete the storage pool from the host.

2. Add the storage pool to the host again.

Failed to add an FC network storage resource for a host

Symptom

I receive the "An error occurred, but the cause is unknown" error message when I add an FC network storage resource for a host.

Condition

This issue occurs on hosts that cannot automatically update FC LUN information.

Solution

To resolve this issue, select the HBA from the storage adapter list of the host, and then perform a normal or forced HBA scanning.

Alternatively, restart and reinitialize the host, obtain FC LUN information, and then re-add FC LUNs for the host.

What should I do if the progress bar gets stuck when I attempt to mount an iSCSI shared file system to a host?

Symptom

The progress bar gets stuck during storage pool assignment for a host if PVs, VGs, or LVs have been created on an iSCSI LUN formatted with OCFS2 before you assign it to the host as a shared file system.

Condition

This issue might occur if PVs, VGs, or LVs have been created on an iSCSI LUN formatted with OCFS2 before you assign it to a host as a shared file system.

Solution

To resolve this issue:

1. Access the storage device to delete the LVs, VGs, and PVs in order.

2. On CVM, navigate to the host pool, click the tab for shared file system management, and then reformat the disk of the shared file system.

3. Navigate to the host, click the tab for storage management, and then add the shared file system as a storage pool to the host.

Failed to enable a shared file system on a managed host

Symptom

I cannot enable a shared file system on a managed host that uses the virtual disk on an FC SAN or iSCSCI SAN storage server.

Condition

The host has read-only access to the FC SAN or iSCSCI SAN storage server.

Solution

To resolve this issue:

1. On CVM, migrate the VMs on the host to any other host or place them in maintenance mode.

2. Suspend all shared file systems on the host.

3. On the FC SAN or iSCSI SAN storage server, assign the read-write access permission to the host.

4. Restart the host.

5. Enable the shared file systems on the host.

6. Move the VMs back to the host or exit maintenance mode.

What should I do if I receive an error message when I add a storage pool that is Windows shared directory type in CVM?

Symptom

I receive the "Requested operation is not valid: CIFS server maybe not available, please check the configuration" error message when I add a storage pool that is Windows shared directory type in CVM.

Condition

This issue typically occurs if the general and advanced IP settings for the network connection on the Windows server are inconsistent.

Solution

To resolve this issue:

1. In Network and Sharing Center on the Windows server, click the connection in use, and then click Properties to manage the network properties.

2. Select Internet Protocol Version 4 (TCP/IPv4) Properties, and then click Properties to identify the basic IP settings for the connection.

3. Perform the following tasks depending on the IP assignment method configured in the General tab:

• If the option to obtain an IP address automatically is selected, click Advanced, and then select the Enable NetBIOS over TCP/IP option in the Wins tab of the Advanced TCP/IP Settings window.

• If an IP address is configured, edit the IP address list in the IP Settings tab of the Advanced TCP/IP Settings window. Make sure the IP address list contains only the IP address configured in the General tab.

What should I do if an error occurs when I suspend or delete a storage pool?

Symptom

The "internal error Child process (/bin/umount /vms/target3) status unexpected: exit status 1" error message is displayed when a storage pool is suspended or deleted.

Condition

This issue might occur if some processes on the host are using the directory in which the storage pool is mounted.

Solution

To resolve this issue:

1. Log in to the host by using SSH.

2. Execute the lsof +d /vms/target command to identify the processes that are using the directory. The target argument represents the directory name, target 3 for example.

root@vmc-216:~# lsof +d /vms/target3

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME

bash 11349 root cwd DIR 8,16 3896 513 /vms/target3

vim 12138 root cwd DIR 8,16 3896 513 /vms/target3

vim 12138 root 3u REG 8,16 12288 1412504 /vms/target3/.test.txt.swp

3. Execute the kill -9 process-id command to kill one of the processes. Then, repeat the lsof +d /vms/target command and the kill -9 process-id command to kill the remaining process one by one until all processes are killed.

root@vmc-216:~# kill -9 11349

root@vmc-216:~# lsof +d /vms/target3

4. In CVM, suspend or delete the storage pool.

The storage pool of the shared file system type cannot be used as an NFS or file system. It can only be used as the image storage of local CVK hosts. Violation of this restriction might also cause unmount failures (the lsof command cannot find the processes that are using the storage pool) or other problems.

 

How do I resolve the insufficient storage issue that occurs when I perform a file upload or download on CVM?

Condition

This issue occurs if the /vms directory of CVM does not have sufficient space for the file.

Solution

To resolve this issue, delete or move unused files from the /vms directory until the free space is larger than twice the file size.