3.5.1 Matrix Server Release Notes

PolyServe Release Notes 23

12379 Client mounts hang indefinitely

The standard Linux NFS implementation has a defect that

prevents the successful export of filesystems or directories that

reside on certain devices. The symptom is that client mount

attempts hang indefinitely. The defect is not related to Matrix

Server or the PSFS filesystem.

The affected devices have major or minor device numbers

greater than 255. To determine if an exported directory is

affected, take the following steps:

•Using df, determine the device on which the directory

resides. The first column of output contains the device name.

•Using ls -l <device_name>, determine the properties of the

device. The comma-separated fifth and sixth columns,

(between the user/group information and the timestamp)

contain the major and minor device numbers.

If either number is greater than 255, directories on this

filesystem cannot be successfully exported by NFS.

The minor device number assignment cannot be controlled in

any practical manner. It depends on the order in which devices

are discovered by the Linux operating system, and is not

guaranteed to be unchanged across reboots. Under normal

circumstances, minor device numbering is relatively stable

across reboots but major changes in attached storage can have

major effects on numbering. The only absolutely guaranteed

method to avoid this defect is to limit the total number of raw

devices plus partitions to less than 255, for any given major

device (such as PSD or PSV).

New filesystems intended for export by NFS should be created

on devices or volumes with minor device numbers substantially

less than 255. Existing filesystems to be exported by NFS must

be copied from an affected device to one that will not be

affected.

Defect Description