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Arctera InfoScale™ Cluster Server 9.0 Bundled Agents Reference Guide - Linux

Last Published: 2025-04-27

Product(s): InfoScale & Storage Foundation (9.0)

Platform: Linux

RHEL 7 and RHEl 8: Configuring bind mounts

RHEL 7 supports bind mount, but it does not display the bind flag with the mount point. In case of bind mounts, the mount command displays the parent block device and file system type instead of the block device and "bind" option used while performing a bind mount. The mount command output displays the bind mount as a parent block device mounted on multiple mount points. Due to this behavior, the Mount agent is unable to determine bind mounts and any mount resource with FSType=bind fails to come online and the Mount agent reports the resource state as UNKNOWN. You can configure FSType=bind in other Linux versions.

The Mount agent now allows the same block device to be mounted on multiple mount points, so to configure a bind mount in VCS, use the parent block device and file system type.

Note:

While configuring bind mounts, set BindUmount =1 only for the resource that is the lowest in the hierarchy. For VxFS, the value of SnapUmount and CkptUmount must always be 1 for each resource.

In case of VxFS, if any of the following conditions is true, bind mounts, snapshots, and checkpoints cannot be unmounted:

Snapshots are found, but the SnapUmount attribute is set to 0.
Checkpoints are found, but the CkptUmount attribute is set to 0.
Snapshots and checkpoints are found, but either the SnapUmount or the CkptUmount attribute is set to 0.

In any of these conditions, the Offline entry point of the Mount agent exits without unmounting the snapshots, checkpoints, and bind mounts. It logs an error message and then invokes the clean entry point.

RHEL 7 and RHEL 8: Sample bind mount configuration

Set VxFSMountLock = 1 only for the topmost resource in the resource dependency tree. For all the other mount resources, set VxFSMountLock = 0. For bind mount, the kernel simply clones the mount options and hence the pseudo file inherits the same mount lock information locking the other resources.

Mount share_mnt2_bind (
                MountPoint = "/bind_point2"
                BlockDevice = "/dev/vx/dsk/bind_dg/bind_vol"
                FSType = vxfs
                FsckOpt = "-y"
                VxFSMountLock = 1
                SnapUmount = 1
                CkptUmount = 1
                BindUmount = 0

                )
       
Mount share_mnt1_bind (
                MountPoint = "/bind_point"
                BlockDevice = "/dev/vx/dsk/bind_dg/bind_vol"
                FSType = vxfs
                FsckOpt = "-y"
                VxFSMountLock = 0
                SnapUmount = 1
                CkptUmount = 1
                BindUmount = 0

                )
        
 
 Mount share_mnt_bind (
                MountPoint = "/mount_point"
                BlockDevice = "/dev/vx/dsk/bind_dg/bind_vol"
                FSType = vxfs
                FsckOpt = "-y"
                VxFSMountLock = 0
                SnapUmount = 1
                CkptUmount = 1
                BindUmount = 1

                )
        // resource dependency
        share_mnt2_bind requires share_mnt1_bind
        share_mnt1_bind requires share_mnt_bind
        share_mnt_bind requires dg_res_bind