Modifying /etc/hosts

[Arjun Kandasamy]

Hi


Can anyone confirm if there are issues with modifying /etc/hosts while a server is in use?


kind regards


AK

[Jeff Schussele]

Hi AK,

Absolutely none at all.
It's used only as a lookup table.

Rgds,
Jeff

[Robert-Jan Goossens]

Nope not at all,

Just keep a copy in a save place.

Regards,
Robert-Jan

[Pete Randall]

AK,

Should be absolutely no problem at all!


Pete

[Marco Santerre]

You can modify /etc/hosts any time you want.

I've done it several times

[A. Clay Stephenson · Accepted solution]

With the caveat that you don't introduce syntactic or logical errors to the hosts file then no there are no problems at all. The next gethostbyname() invoked by an application will immediately see the new host. If /etc/hosts is the map for NIS hosts then you must also invoke a ypmake to push the changes out.

[Sridhar Bhaskarla]

Hi AK,

I would not mind modifying /etc/hosts as long as I only add entries. I would think twice if I have to modify an existing entry as it may have an impact on the application. Some softwares like corba/tuxedo may not work unless you make changes on both ends of the connection.

-Sri

[doug mielke]

A couple of notes:
/etc/hosts is read sequentially, so keep the localhost entry near the top, and remember that if there are duplicates. only the first one will be recognised.

[Steven E. Protter]

It depends what you do to it.

If you take out the loopback address 127.0.0.1 you can mess up the server quite badly.

If you change the ip address of the host, you can mess up networking as well.

If you are adding entries to /etc/hosts for other servers the impact is less drastic.

If you are new, make and test these changes in a maintenance window.

SEP

[Arjun Kandasamy]

Thanks for the replies. We maintain a centralised hosts file on one server and then rcp it across out other servers. On of my colleagues has noticed that during the time of the actual rcp we suffered a number of disconnects in the SAP/OMNI/PATROL logs. The changes we are making to the source hosts file are 99.9% to do with addition/deletion of entries for printers.

AK