Changing /etc/fstab

[Adrian Jang]

Hello,

I’m trying to make a logical volume support large files (i.e. >2GB). I understand that this can be performed by modifying the /etc/fstab file. The /etc/fstab file on my server is presently as follows:

# System /etc/fstab file. Static information about the file systems
# See fstab(4) and sam(1M) for further details on configuring devices.
/dev/vg00/lvol3 / vxfs delaylog 0 1
/dev/vg00/lvol1 /stand vxfs tranflush 0 1
/dev/vg00/lvol4 /home vxfs delaylog,quota 0 2
/dev/vg00/lvol5 /opt vxfs delaylog 0 2
/dev/vg00/lvol6 /tmp vxfs delaylog 0 2
/dev/vg00/lvol7 /usr vxfs delaylog 0 2
/dev/vg00/lvol8 /var vxfs delaylog 0 2
/dev/vg00/acc7ora /acc7ora vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/QoSManData /QoSManData vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/QoSManager /QoSManager vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/depot /depot vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/depot_bu /depot_bu vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2


I'd like to *change* it to be as follows:

# System /etc/fstab file. Static information about the file systems
# See fstab(4) and sam(1M) for further details on configuring devices.
/dev/vg00/lvol3 / vxfs delaylog 0 1
/dev/vg00/lvol1 /stand vxfs tranflush 0 1
/dev/vg00/lvol4 /home vxfs delaylog,quota 0 2
/dev/vg00/lvol5 /opt vxfs delaylog 0 2
/dev/vg00/lvol6 /tmp vxfs delaylog 0 2
/dev/vg00/lvol7 /usr vxfs delaylog 0 2
/dev/vg00/lvol8 /var vxfs delaylog 0 2
/dev/vg00/acc7ora /acc7ora vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/QoSManData /QoSManData vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/QoSManager /QoSManager vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/depot /depot vxfs rw,suid,nolargefiles,delaylog,datainlog 0 2
/dev/vg00/depot_bu /depot_bu vxfs rw,suid,largefiles,delaylog,datainlog 0 2 <----------------


Question:
Is it necessary to shut down the server to single user mode to change the /etc/fstab file? Or can the /etc/fstab file be changed at any time with the changes taking effect immediately?

Thank you.

[James R. Ferguson]

Hi:

> Iâ m trying to make a logical volume support large files (i.e. >2GB). I understand that this can be performed by modifying the /etc/fstab file.

No, that is absolutely wrong. The 'largefiles' bit of the filesystem itself enables largefiles to be created when set. If not set, no largefiles are allowed. You can enable largefiles with 'fsadm', as for example:

# fsadm -o largefiles /mountpoint

The mount option 'largefiles' or 'nolargefiles' in '/etc/fstab' if used at all must match the underlying setting of the filesystem in order for a mount request to succeed. In that sense it is purely documentary.

> Is it necessary to shut down the server to single user mode to change the /etc/fstab file? Or can the /etc/fstab file be changed at any time with the changes taking effect immediately?

You can edit and save the 'fstab' file at any time. If you havedadded a new mountpoint, one easy way to handle it is to modify 'fstab' and issue a 'mount -a' to mount your new filesystem. This also checks the change you made to 'fstab' for the next time (usually at a boot/startup) that the file will be processed.

If you are changing the mount options of a filesystem, either unmount it and handle the modified options by doing a 'mount -a' or use the '-o remount' option for the filesystem at a command line for 'mount'. See the manpages for 'mount_vxfs' for more information.

Regards!

...JRF...