NFSv4 Broken in CentOS 6.5 – Reboots necessary to revert to NFSv3 until fixed.

I apologize for the interruptions in web, mail, and shellx service today.  This was necessary because the upgrade to CentOS 6.5 broke the NFSv4 clients badly.

NFS is networked file system, it’s how common files like your home directory and mail spool are available on multiple machines.

NFSv4 doesn’t pass numerical user ID’s over the wire like previous version of NFS did.  Instead, it passes names which are mapped by idmapd, which up until recently worked.

Unfortunately, the NFS version 4 client in CentOS 6.5 is sometimes passing a numerical UID over the wire instead of a name and then when idmapd tries to look it up, it fails, resulting in the file ownership being mapped to nobody.

Reading the CentOS and RedHat forums, it’s clear that we’re not the only people having this problem, it’s also clear the developers don’t yet have a clue what is causing it, so a fix may be awhile.

I apologize for the somewhat slower response this is going to cause in the meantime but random user ID mapping is not a workable situation.

One thought on “NFSv4 Broken in CentOS 6.5 – Reboots necessary to revert to NFSv3 until fixed.

  1. For what it’s worth, I’ve been able to determine that it is partially a kernel problem, partially something else. If I use an older kernel, uid mapping works but gid mapping is still broken.

Leave a Reply