A Network File System (NFS) client is part of a kernel. After you install an NFS client, errors may occur due to pre-existing bugs in the kernel. To ensure the stability of NFS, we recommend that you use the kernel versions verified by Alibaba Cloud.

Recommended Linux versions

We recommend that you use official kernel images tested and verified by Alibaba Cloud to ensure system stability. For more information, see Recommended kernel images.

NFS response errors due to a kernel bug in network stacks (priority: high)

An NFS response error may occur to Linux kernel versions between 2.6.32-296 and 2.6.32-696.10.1 (excluding 2.6.32-696.10.1). If the NFS server is too busy to process a request within the timeout period and the request is retransmitted repeatedly, a network stack error may occur. This results in an NFS response error.

If the "operation failed" message appears, we recommend that you restart the ECS instance that hosts the client. For more information, see RHEL6.9: NFSv4 TCP transport stuck in FIN_WAIT_2 forever.

NFS response errors due to a kernel bug (priority: high)

  • An NFS response error may occur if an NFS server failover occurs when you open a connected NFS client or access a file system by using the NFS client. The failover may result in a deadlock, which may cause an NFS response error. Such NFS errors may occur to the following kernel versions:
    • RHEL 6 or CentOS 6 2.6.32-696.3.1.el6
    • RHEL 7 or CentOS 7 3.10.0-229.11.1.el7 and earlier versions
    • Ubuntu 15.10: Linux 4.2.0-18-generic

    If the "operation failed" message appears, we recommend that you restart the ECS instance that hosts the client. For more information, see RHEL7: NFSv4 client loops with WRITE / NFS4ERR_STALE_STATEID - if NFS server restarts multiple times within the grace period.

  • An NFS system error may also occur if a network partition or network jitter occurs and results in reconnections. This is because the NFS may fail to correctly process the relevant error codes. Such NFS system errors may occur to the following kernel versions: The bad sequence-id error keeps appearing in system logs.
    • RHEL 7 or CentOS 7 3.10.0-229.11.1.el7 and earlier versions
    • RHEL 7 or CentOS 7 3.10.0-229.11.1.el7 and earlier versions

    If the "operation failed" message appears, we recommend that you restart the ECS instance that hosts the client. For more information, see RHEL6 / RHEL7: NFS4 client receiving NFS4ERR_BAD_SEQID drops nfs4 stateowner resulting in infinite loop of READ/WRITE + NFS4ERR_BAD_STATEID.

Unsupported chown command and system API calls (priority: Low)

When the kernel version is 2.6.32, the chown command and system APIs are not supported on an NFS client.

Unable to stop an ls operation (priority: Low)

When the kernel version is 2.6.32-696.1.1.el6 or earlier, you cannot stop an ls operation. This occurs when you create or delete files or folders while the ls operation runs.

To fix the issue, we recommend that you upgrade the kernel to the latest version.