Files and Data

What is gaia?

Strictly speaking, gaia is the name we've given to the top directory of all the nfs mounts and is only related to remotely mounted disk partitions. But you can think of it as the UNIX network. You don't need to care where a file physically is (unless the disk crashes) since you can get to it using the same path from anywhere on the Sun network.

Let's use home directories as an example. Physically, my home directory is /smeagol/home/home/withers and is on the /smeagol/home directory (i.e. the /dev/dsk/c1t1d0s4 partition on the host named smeagol). But through the magic of the automounter, it appears to me as if my home directory is /gaia/home/withers. No matter what machine I login to it is always /gaia/home/withers and that always points to the same real disk where my home directory and files are. This way, when I get a new machine and change the physical location of my home directory, it is still /gaia/home/withers and I don't have to go through the painful process of changing all my paths.

We can use the fdl partition as another example. This is a disk set up for storing data collected with the portable seismic array housed in the Field Deployment Lab (FDL). Physically it exists on the file server in room 218 in 3904. If I want to view it, I cd /gaia/data/fdl. That is true no matter what sun computer I'm on. If you're in the fdl group you can also write in that directory but that's another FAQ.

Each Sun workstation that shares a file system also does so within the gaia namespace. It is similar to the Solaris implementation of /net. File systems attached to specific hosts are available through this name space under /gaia/hostname where hostname is whatever the machine, or host, was named.


Where can I store files?

If you have a computer on your desk, it is always fastest to store them there. However, be warned that we do not back up the computer on your desk so if your disk crashes, your files are gone. Always back up important files or keep them someplace that is backed up.

UNIX: The general use partition is /gaia/scratch/200GB. If you use this disk please create a directory with your user id as the name and put all your files in there. You can put whatever you wish there but please clean up after yourself. If you fill it with your trash or ancient files you'll never look at again, you're using space that might better be used by someone else. Also be warned that this disk is not backed up. No, files are not automatically deleted from this directory so please clean up after yourself.

Also on the file server are a few partitions for specific projects that have contributed funds for diskspace. These include /gaia/data/fdl, gps, and bodat. If you need additional disk space, speak to your advisor/supervisor or see Mitch Withers to discuss options for a centralized solution (and be prepared to contribute funds for hardware).

PC: You can store files on the so-called Z drive accessible from any PC in the network. This disk is physically located on the PC server strider and is backed up.


Can I see other people's files?

Only if they let you.


How can I let other people see my files? Prevent other people from seeing my files?

UNIX: Usually the default is that everyone has read permission on your files. To change this use the chmod command. Unix has three levels of permissions: user, group, and other. Grant group read to allow others in your group to see your file and grant other read permissions to allow anyone on the network to see your file. PC: Right click start and open an explore window. Navigate to the particular file you want to share. Right click on the file and select properties. Go to the security tab. Highlight the username for which you wish to adjust permissions (you may need to click add first if the person doesn't already have some type of permission. Select the appropriate permissions by checking the various boxes either allow or deny. Click OK when you're done.


How do I share files with someone off campus?

Not through remote disk mounts, that's for sure. CERI supports two mechanisms for sharing files with folks off campus..

1.) UMDRIVE

Umdrive is a University sponsered resource. Point your browser to http://umdrive.memphis.edu for further instructions.

2.) Anonymous FTP (Effective 10/30/04)

CERI maintains an anonymous ftp server at ftp.ceri.memphis.edu. You can read more about FTP at the FTP FAQfor further instructions about how to use ftp.

You can make use of the anonymous ftp server in the following ways:

A.) Have off campus colleagues upload files by ftping to ftp.ceri.memphis.edu and depositing files into the /pub/in folder.

B.) Have off campus colleagues download files by ftping to ftp.ceri.memphis.edu and extracting files from the /pub/out folder.

You can navigate to the /pub/in and /pub/out folders on CERI's unix computer network with the command "cd /gaia/home/ftp". You can navigate to the /pub/in and /pub/out folders on the pc network by searching network neighborhood for ftp-ceri.

Anyone at CERI should be able to write to the /pub/out folder from a pc or unix host. Anyone at CERI should be able to read from the /pub/in folder from a pc or unix host.

Please note that the files in the /pub/in and /pub/out get deleted every Sunday at noon.


How much space do I have?

UNIX: Generally quotas are kept very small (150Mbytes) but there are other places to store your files besides your home directory. Using links from your home directory (see the ln command) for frequently accessed files is often convenient.

PC and other UNIX file systems do not have strict quotas placed on them. However the disks are of finite size so if you fill it up with trash, other people will get mad at you. Please be considerate.


Are my data backed up? How do I back up my data?

In general, no, your files are not backed up. However specific partitions (like the Z drive on strider and /gaia/data) are backed up.

Some other options to do your on backups include:
obtain a tape drive or find someone with one and copy your files to tape,
copy your most critical data to a cd, dvd, zip drive, etc,
sftp it to your home computer.

I'm sure there are other creative ways that I'll be happy to add if you tell me. We're working on ways to help people back up their data but they are all in the development phase.


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