cron,at & batch and copy tape to another tape

[Ngoh Chean Siung]

Hi,

1) What is the diff among cron, at & batch? As I know, at is used to execute the job once in a specific time. But cron also can do that, right. I hv read some linux manual and found that cron is used when the system is running continuously. What does it means? For batch, it is same as at but it can be configured to run a job if the load average is at certain figure. Am I right?

2) How to duplicate a dds tape (with fbackup, tar or ...) to another empty or not empty tape?

regards.

[njia_1]

Hi

for second question, if you have ignite install, there is a command called "copy_boot_tape"

if you need to copy the files to your filesystem first then make sure that file system support largefiles, otherwise you will get a end of file error.

first question,
according my understand, cron is used if you want to run a program at the specific time and more than once. For example, clear all the logs monce a month.

at is used if you just want to run something once at a specific time, for example, when I do a make_tape_recovery I alwasy use "at"
at now
make_tape_recovery -AvI
^d

this makes sure if my telnet or ssh session is lost, that make_tape_recovery will continue running until finishes but only once.