Weird question....

[tezro]

Hello everybody
Does anyone know what the latest version of CentOS is to support the EFS filesystem? Or whether it is possible to enable it in the latest versions?

[TrevorH]

Google says EFS is used via NFS and all CentOS versions support that.

[tezro]

Google says EFS is used via NFS and all CentOS versions support that.

Nope, Extent File System (EFS) is an older extent-based file system used in IRIX (Silicon Sraphics machines based on MIPS microprocessor) releases prior to version 5.3.

[TrevorH]

EFS is also Amazon Elastic Filesystem which is far more recent and much much more widely used so searching for what you're after is somewhat tricky.

As far as I can see linux has only ever allowed read only access to it using a kernel module that 's enabled using CONFIG_EFS_FS so I checked on all of CentOS 7, Rocky8 and 9 and Fedora 38 and on all of them grep CONFIG_EFS_FS /boot/config-$(uname -r) says

# CONFIG_EFS_FS is not set

I no longer have CentOS 5 or 6 VMs installed so I cannot check on those but I downloaded the .config file used to build the CentOS Plus kernel for EL5 from https://wiki.centos.org/attachments/Add ... entos.plus and that also has the same commented out line saying "not set". It's also not set in https://wiki.centos.org/attachments/Add ... .1.plus.c4 nor in https://wiki.centos.org/attachments/Add ... 4.21-47.EL

So I think there is no version of CentOS that has ever been able to read this version of EFS.

Your only option really would be to build your own kernel with that option enabled and then boot that. Or alternatively and possibly easier, boot the version of IRIX you need in a VM, attach a copy of the filesystem to that and then copy the contents onto a filesystem from the 21st century.