Sharing Files

Attaching a file to email is a common and familiar way of sharing a file with others, but email was never designed as a way to transfer files. In fact today's large files can overwhelm a mail server. Fortunately there are many other ways to share files, most of them just as easy as sending an attachment. Most of them offer other advantages over email as well.

Different Ways to Share Files

The "right" way to share a file will depend on the situation, so it is a good idea to know your options. A few relevant questions are:

Are all the people who need to see the file SSCC members?
Is it important that other people not see the file?
How often will you be sharing files with these people?
Do they need to make changes and then share them with you?
What kind of Internet connection, software, etc. do your intended recipients have?

Public Network Space

All files on the Y: drive are accessible to any SSCC member, so one quick way to share files is to put them on the Y: drive. Just make yourself a folder (give it your name so it's easy to tell who it belongs to), put the files in it, and tell the others where they can get it.

Advantages of this method:

It's very quick and easy.
Winstat allows SSCC members to log in remotely and access the Y: drive.

Disadvantages of this method:

Any SSCC member can view files on the Y: drive, and in theory they could delete or modify them.
Files on Y: are automatically deleted after 30 days.
Only SSCC members can access the Y: drive.
Remote users must be able to log in to the SSCC network to view the file.

Shared Network Space

Linux and Windows have the ability to define groups which can share files on the network. A group can have a central location where shared files are stored--here at the SSCC we call these project directories. Windows project directories are stored on the X: drive, while Linux project directories are stored under /project, available from Windows as the V: drive. If you need to repeatedly share files with the same people, setting up a group is a very easy way to do it.

If you need to have a group created or would like a shared directory for your group, please contact the Help Desk.

Advantages of this method:

You control who can view the file (by specifying who is in your group).
They can change the file and easily make the changes available to you.
The file is backed up regularly.
Winstat allows SSCC members to log in remotely so they can access shared files.

Disadvantages of this method:

Only SSCC members can be part of a group on our network.
Remote users must be able to log in to the SSCC network to view the file.
You will need to contact the Help Desk to have people added to or removed from your group.

The Web

You can make any file available on the SSCC's web server. All SSCC users can set up a web site, and it's not as difficult as it may sound. Take a look at Publishing a Web Site on the SSCC's Web Server.

If the file should not be available to the general public it is possible to password-protect a web page so that only people with a user name and password you provide can view it. Please see Limiting Access to a Web Page for instruction on setting it up.

You can put the file on the web server as is, or in some cases (a Word document for example) you can convert it to an actual web page so no software is needed to view it other than a web browser.

Advantages of this method:

The file is available to anyone with Internet access, regardless of location or SSCC affiliation.
If you password protect the file, you control who can view it by giving them the user name and password.
If you convert the file to a web page, the recipient does not need to have the same software you do in order to view it.

Disadvantages of this method:

Unless you password protect the file anyone can access it.
Web passwords are sent in plain text and there is a small chance someone could intercept it--this method is not secure enough for sensitive data.
Users cannot change the file and make the changes available to you.

CD

The SSCC has CD burners available in 2470, 3218, and 4218 Social Science. If you need to share a large file or a large number of files, you can burn them onto a CD and then distribute the files by distributing the CD, by mail if necessary. This is also an excellent way to take files with you when you change locations.

Advantages of this method:

The recipients of the file do not need a fast Internet connection or any Internet connection at all.
You control access to the files by controlling physical access to the CD.
You can share very large files or a large numbers of files without having to wait for them to be sent over the Internet.

Disadvantages of this method:

Users cannot change the file and make the changes available to you.
The recipient must have access to a CD-ROM, CD-R or DVD-ROM drive to read the file.
Distributing a CD may not be as convenient as sending the file over the Internet.

SFTP

Secure File Transfer Protocol (SFTP) is a method of moving files between a server and a PC, or between two servers. For information on using SFTP, please see Transferring Files Using SecureFX or Using SFTP. To share a file with others via SFTP, you will need to use anonymous FTP.

Advantages of this method:

Sending a file to yourself by SFTP is very quick and easy, so this is a good way to move a file between computers or networks.
With anonymous FTP the file is available to anyone with Internet access, regardless of location or SSCC affiliation.

Disadvantages of this method:

SFTP requires either working with the command line or installing an SFTP program.
You cannot password protect a file with anonymous FTP.
Many people are unfamiliar with SFTP

Paste

If the file you want to share is just a short piece of text, you can paste the whole thing into the body of your email message rather than sending it as an attachment.

Advantages of this method:

The text will always be available and easily located as long as they keep the message.
The recipient does not need to have the same software you do in order to view the file.

Disadvantages of this method:

The recipient has to keep the email message in order to keep the information.
Depending on the email programs used by the sender and recipients, special formatting may not be available or easily read.

Email Attachment

You can send the file as an email attachment.

Advantages of this method:

You can distribute copies to a number of people at once, and the distribution is under your control.
The recipient doesn't have to take any action to get the file other than checking their email.

Disadvantages of this method:

Very large files and some file types will be refused by many mail servers. The SSCC's mail server will reject attachments larger than 50 megabytes. See Virus Protection at the SSCC for a list file types that are filtered.
Some recipients may use web-based email or email programs that don't handle attachments easily.
Mail protocols were not designed to transfer files, and a large attachment sent to many users can overwhelm a mail server.

Compressing Files

With any of these options, the file transfer will be quicker if the file is smaller. You can compress many files and reduce the size considerably. This is especially important when sending files as email attachments. For more information on file compression, see Using Compressed Data in Windows or Using Compressed Data in Linux. Compressing and uncompressing a file takes a few moments and adds an extra step to working with the file, but with large files it is a necessity.

File sizes and the degree to which they can be compressed varies widely. The general rule is that text is small but pictures are big. Hundreds of pages of text will normally take up only a few megabytes of disk space, while one picture can easily do the same. Furthermore, text tends to compress better than pictures, partly because many picture formats are already compressed. The size of a data file is of course dependent on the number of variables times the number of observations plus some overhead, but usually compresses quite well. However there is so much variation that it's impossible to predict the size of a file or how much it can be compressed without actually looking. If you know that a file takes longer than most to open, you should probably check its size before deciding how to send it to someone else.

Finding the right way to share files in your particular situations may take a little thought, but you'll find the extra convenience and efficiency well worth the effort.

Last Revised: 3/2/2009