System Administration Stuff
Course Lockers
Below I will present some basic stuff this will help you track down and correct some of the problem that you may encounter while using
the cse lab facilities and some general stuff hope it helps you avoid coming to the updaters :)). ALWAYS TRY TO CONSULT YOUR SENIORS BEFORE SHOOTING MAILS AT UPDATERS over these issues. At the end i have given instructions that should be followed while writing about problems to updaters.I have recently started to enlist most frequently asked things(FAQ) in my blog have a look at them, hopefully you shall find some solution there for your problem
- MAIL BOX SETTINGS
We
have IMAP server running at desh (10.20.3.2) that also is the
only outgoing smtp server allowed to our department. So make
following changes to the '.pinerc' :
user-domain=cse.iitd.ernet.in
# to avoid local machine name from showing up in outgoing mail
nntp-server=news.cse.iitd.ernet.in
smtp-server=desh.cse.iitd.ernet.in # smtp server for outgoing mail 10.20.3.3 will also do
#if you don't have SSL then the parameters SSL should be removed , remember you imap connection won't be secure
inbox-path={desh.cse.iitd.ernet.in/SSL/novalidate-cert/user=your_userid}inbox
nntp-server=news.cse.iitd.ernet.in
smtp-server=desh.cse.iitd.ernet.in # smtp server for outgoing mail 10.20.3.3 will also do
#if you don't have SSL then the parameters SSL should be removed , remember you imap connection won't be secure
inbox-path={desh.cse.iitd.ernet.in/SSL/novalidate-cert/user=your_userid}inbox
#place where you sent-mail etc will be stored
folder-collections="Local mail" mail / []
- PROXY SETTINGS
We have
a http-squid proxy server running at pushpa(10.20.5.2) , note
that this is just a http/https servers , don't set it as the ftp-proxy
or proxy for some other protocol. To comfigure Netscape/ Mozilla (or its
siblings as firefox etc.) do the following:
Go to Edit->Preferences->Advanced->Proxies->Manual......->Http proxy
Enter 10.20.5.2 (better still pushpa.cse.iitd.ernet.in) for proxy
Enter 8080 for the Port
For other browsers locate where you can set thwe proxies ...use the help they provide
Go to Edit->Preferences->Advanced->Proxies->Manual......->Http proxy
Enter 10.20.5.2 (better still pushpa.cse.iitd.ernet.in) for proxy
Enter 8080 for the Port
For other browsers locate where you can set thwe proxies ...use the help they provide
- SSH ISSUES
Configuring ssh for auto-authentication.
1. Generate
dsa keys by ssh-keygen2
2. Generate rsa keys by ssh-keygen2 -t rsa
3. cd to .ssh2
4. create files identification & authorization by
touch identification
touch authorization
5. cp ~/.ssh2/id_rsa_1024_a.pub ~/.ssh/authorized_keys
6. cd ~/.ssh
7. edit authorized_keys to make it look like one given below
In particular ensure.
2. Generate rsa keys by ssh-keygen2 -t rsa
3. cd to .ssh2
4. create files identification & authorization by
touch identification
touch authorization
5. cp ~/.ssh2/id_rsa_1024_a.pub ~/.ssh/authorized_keys
6. cd ~/.ssh
7. edit authorized_keys to make it look like one given below
In particular ensure.
a. The
file has only one line. ( remove line breaks manually )
b. Remove comment lines
b. Remove comment lines
Try ssh some_machine it should work without passwd
.ssh2/identification
IdKey id_rsa_1024_a
.ssh2/autorization
Key id_rsa_1024_a.pub
.ssh/authorized_keys
ssh-rsa AA45237424742424hhgkhgksdg.........(and so on till =)
'sftp' blues
Remember
that sftp accepts no output from the execution of '.bashrc' and
shall give an error complaining about length of the received message. So
either remove all the commands that generate message to stdout(console) as
cal, fortune etc. or do the following:
#check for the SSH_TTY variable is null and also the shell is interactive i.e it has its $PS1 variable set.Note that a better check shall be that $- variable contains an ’i’ :))
if [ $SSH_TTY = "" ]; then
fortune
........your commands go here....
........
fi
#check for the SSH_TTY variable is null and also the shell is interactive i.e it has its $PS1 variable set.Note that a better check shall be that $- variable contains an ’i’ :))
if [ $SSH_TTY = "" ]; then
fortune
........your commands go here....
........
fi
- NFS stale handle and NIS DOMAIN not bound:
These problems
arise when the NFS servers or the NIS servers for some reason become unavailable.
Try to be patient for some time as most probably some one will be at work
to make the thing moving again. For stale handles try logging in again after
some time. If you had just booted the machine and these problems appear then
inform the local administrator. If find no one near try rebooting the
machine .
Remember that you must ensure that everybody logged on to the machine is informed before you reboot( use finger to find who all are logged on to the machine)
Remember that you must ensure that everybody logged on to the machine is informed before you reboot( use finger to find who all are logged on to the machine)
- /usr/local not available
The most
probable reason is that its not mounted on to the machine try looking for
local admin. or reboot after some time if things don't change (refer above
for precautions)
- Request for installation of new library or software on the user local or some problem with the software there
- Quota limit problems (wrong reporting of space usage)
- Problems with our scripts for password alias etc.
- Demand for backup (Please avoid rm
-rf :)) and do what you are asked )
Inform the updaters, BUT FOLLOW THE INSTRUCTIONS BELOW
INSTRUCTIONS FOR INFROMING THE UPDATERS:
- Always report the problem in the main message , don't put the entire message in the subject
- Always report with the error message attached ( its a must of any problem reporting)
- Write to the updaters group not the members (indiviatticly)
- Remember system administration is voluntary work in our department so please be patient and keep your cool ;),mind you its your work that the updaters shall be doing .
Thanks -- Avinash
