Extended Attributes (xattr)

Table of Contents


This document is only valid when using Infinite Scale version 2.0. Starting with version 3.0, Infinite Scale has switched to the messagepack backend for metadata.

Check xattr Support

Check if extended attributes are supported if selected as metadata backend

When selecting the xattrs backend for storing metadata, the used POSIX-compliant filesystem from the tables above must support it. You can check this with the following commands, change to a location in the mounted filesystem you want to check before:

touch foo.txt && attr -s mix -V bar foo.txt
Attribute "mix" set to a 3 byte value for foo.txt:
attr -g mix foo.txt
Attribute "mix" had a 3 byte value for foo.txt:
rm foo.txt
NFS Notes

When using NFS and the xattrs backend, you have to take care that the NFS server AND the NFS client provides Extended Attributes.

NFS Storage Based on Linux Servers

When using a kernel version 5.9 or higher, extended attributes for the NFS server and the NFS client are part of the system. To check, run the command:

uname -r

On the system providing the NFS server AND on the NFS client check the displayed version number.

NFS Client

If you have an NFS server capable of extended attributes but you are unsure if your client accessing the server supports it, check the nfs-utils or nfs-common package version of your NFS client with the command:

mount.nfs -V

You need at minimum NFS version 2.6.1. For more details see the general NFS Utils Release History and the Ubuntu nfs-common Packages.

NFS Servers Provided from Storage Vendors

A certification matrix will be provided when available.

NFS Protocol Version

Note that if the kernel or the storage system supports extended attributes, you have to use NFSv4 in order to use it.