mounting-turbo-on-linux.md

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default	Mounting Turbo Volume on Linux Machines	120	Guide to mount Turbo volume for new servers.	/mounting-turbo-on-linux

Add linux machine to Turbo export list:

• Go to SRS portal and modify the Turbo volume export list by adding the new linux machine's hostname to the list.

• Go to ARC portal to view/modify user access to the Turbo volume. It also shows current remaining disk space on the Turbo volume.

Mount/Un-mount Turbo Volume on Linux Machines

Mount:

sudo mount -t nfs coe-chaijy.turbo.storage.umich.edu:/coe-chaijy /nfs/turbo/coe-chaijy

Un-mount:

umount -f -l /nfs/turbo/coe-chaijy

To fix NFS UID displayed as “nobody”

Overwrite /etc/idmapd.conf with the following (need sudo to write to /etc/idmapd.conf):

[General]

Verbosity = 0
Pipefs-Directory = /run/rpc_pipefs
# set your own domain here, if it differs from FQDN minus hostname
Domain = umich.edu

[Mapping]

Nobody-User = nobody
Nobody-Group = nogroup

[Translation]
Method = nsswitch

Then run:

sudo nfsidmap -c

[Optional] Change UID/GID for a user

This is only needed if a server is not set up by DCO and thus its UIDs and GIDs for the users are not in sync with those in UMich directory.

⛔️️ WARNING: This will break the whole file system for a user if not run properly. Make sure you know what you are doing. Be sure the change the fields with <> in the script with the correct information.

Tell the user to not use the computer until the followings finish.

Use a different user account to log in:

ssh <some_other_user>@<linux_machine_hostname>
sudo su

Log off the user whose UID/GID needs to be changed:

https://askubuntu.com/questions/12180/logging-out-other-users-from-the-command-line

sudo pkill -KILL -u <username>
# modify the necessary username, UID/GID
vim /home/<some_other_user>/change_uid_gid.sh
sh /home/<some_other_user>/change_uid_gid.sh

Below is the change_uid_gid.sh script:

# put the information we need in variables

username=<uniqname>

# looks up current (old) uid
old_uid=<old_uid>
new_uid=<new_uid>

# do dangerous stuff

echo "[$(date)] Changing UID/GID for user $username from $old_uid to $new_uid" >> "$username"_change.txt

# update the user ID and group ID for $username

usermod -u $new_uid $username

groupmod -g $new_uid $username

# update the file ownerships

# NB: you cannot combine the next two chowns, or files where

# only the uid xor the gid matches won't be updated

# change the user IDs
chown -Rhc --from=$old_uid $new_uid /
# change the group IDs
chown -Rhc --from=:$old_uid :$new_uid /

setfacl -m "u:$new_uid:r-x" /media/$username

setfacl -x "u:$old_uid" /media/$username

echo "[$(date)] Finished changing UID/GID for user $username from $old_uid to $new_uid" >> "$username"_change.txt