Caution How you shut down a cluster client depends on whether or not the client has a local disk, and how that disk is being used.
• If the cluster client has no local disk. follow directions under
"Shutting Down a Sinlple Clienf', later in this chapter.
• If the cluster client has a local disk which it is using for swap, and no other client is swapping to that disk, follow directions under "Shutting Down a Simple Clienf', later in this chapter.
• If the cluster client has a local disk which is being used for a file system, or for a combination of swap and a file system, follow directions under "Shutting Down an Auxiliary File Server", later in this chapter.
• If the cluster client has a local disk which other clients are using for swap, but there is no file system on the disk, follow directions under "Shutting Down an Auxiliary Swap Server", later in this chapter.
10
Allowing Users Shutdown Capabilities
A user does not need to be superuser to halt or reboot a cluster node. You can use the / etc/ shutdown. allow file to give permission for specific users to shut down specific computers in the cluster.
vVhat you will probably want to do is to allow the "owners" of workstations in the cluster to shut down their own local nodes. You give this permission by entering the user login name and the cluster node name in the file /etc/shutdown.al101iiT. For example, to allow user fred to shut down client1, make the following entry in /etc/shutdown. allow:
client1 fred
The superuser, and possibly other users, will need to be able to shut down all the cluster nodes, and you may want to allow some cluster nodes to be shut down by anyone. You can use a wildcard character in such cases; for example, the following entry in / etc/ shutdown. allow allows the superuser to shut down all the cluster nodes:
+ root
For more infornlation, see shutdown (1M) in the HP-U.l Reference.
10-8 Booting and Shutting Down Clusters and Cluster Nodes
Caution Be careful when adding entries to /etc/shutdown.allow. This is how it works:
• If / etc/ shutdown. allow does not exist. or exists and is empty (the default), then the superuser, and only the superuser, can shut down any cluster node.
• If / etc/ shutdown. allow is not enlpty, then only the users listed in it can execute the shutdown command, and they can shut down only those systenls listed beside their login names.
If you use / etc/ shutdown. allow, you must make sure that it contains all the permissions you need to grant, including the superuser login and the systems the superuser can shut down.
• An entry in / etc/ shutdown. allow allows an ordinary user to halt or reboot the system named, but not to bring it down to single-user state. This capability is reserved for the superuser.
10
Shutting Down a Simple Client
The tenn simple client refers to a client that you can shut down without affecting any other cluster nodes. A simple client
• Has no local disk or
• Has a local disk which is being used only for swap, and only by that client.
Shut down a simple client as follows:
1. Log in to the cluster client.
You need not log in as superuser to shut down a cluster client if your login name is matched with this systenl in / etc/ shutdown. allow. See "Allowing Users Shutdown Capabilities", earlier in this chapter.
2. Change directories to the root directory using the command:
cd /
3. Make sure that any other users of this cluster client have logged off.
4. Shut down the system:
shutdown -h
10-10 Booting and Shutting Down Clusters and Cluster Nodes
Shutting Down an Auxiliary File Server
An auxiliary file server is a cluster client that has a disk attached to it that contains a file syste111.
Shutting do\vn an auxiliary file server will autOlllatically Ulllllount any file system on the local disk( s).
Use the procedure that follows to shut down a client whose local disk space is being used for:
• A locally mounted file system or
• A locally lllounted file system and distributed swap space (swap space used by other clients).
Caution 1. Make sure that users of clients with local disks do not shut down their computers unless it's safe to Un1110unt any locally mounted file systems.
2. If the local disk or disks also contain swap space that is being used by other clients, shutting down the client that has the disk will also shut down the clients that are swapping to it. Users of clients with local disks 111ust not shut down their computers until it~s safe to shut down all other clients that are swapping to the local disk space.
10
Shut down an auxiliary file server as follows:
Do this on the client that has the disk attached to it.
1. Log in to the client with the local disk.
Note You need not log in as superuser to shut down a cluster client if your login name is Inatched with this systeln in /ete/shutdown.allow. See "Allowing Users Shutdown Capabilities", earlier in this chapter.
You do need to be superuser, however, to override msgno when warning users to vacate locally mounted file systems, as shown in the next step. (Msgno prevents messages being written to the
(This option of mount (1M) does not show file systel11s mounted via NFS mount, and those file systems will not automatically be un1110unted when the client is shut down. / etc/mount - L shows all file systel11s that can be unmounted fr0111 this client, including file systems 1110unted via NFS 1110unt.)
Caution
If your local disk is also being used as swap space by other clients, shutting down your client will also shut down the clients that are swapping to your disk. Warn the users of those clients too.3. Shut down the cluster client:
fete/shutdown -h
10
Shutting Down an Auxiliary Swap Server
An auxiliary swap server is a cluster client that has a local disk to which other members of the cluster are swapping. (vVe use the term distributed swap to describe this kind of swapping.) When you shut down an auxiliary swap server, you shut down all the cluster clients that are swapping to its disk space.
If you're shutting down a client whose local disk is being used for a locally mounted mounted file system as well as distributed swap, follow the procedure under "Shutting Down an Auxiliary File Server", earlier in this chapter, instead.
To shut down an auxiliary swap server, do the following.
Caution Shutting down an auxiliary swap server shuts down all cluster clients that are swapping to this auxiliary server's local disk(s).
Do this on the client that has the local disk.
1. Log in to the client that has the local disk.
Note You need not log in as superuser to shut down a cluster client if your login name is matched with this system in /ete/shutdown.allow. See "Allowing Users Shutdown Capabilities", earlier in this chapter.
2. Shut down the auxiliar~' server:
fete/shutdown -h
10-14 Booting and Shutting Down Clusters and Cluster Nodes