Perl language have bit different mechanism when dealing with errors. Some points you should know before debugging errors.
1)Always use shebang statement with -w option as shown below.
2)Always use strict and warnings package to report all syntax errors.
When you get above error do not just check error on the given line try to check before and after the line of error report. This tip will resolve most of your errors like missing closing brace "}", sentence termination like ";", etc.
This issue will come when you are using EOF or EOM string to send multiple line to a perl print statement or a command. Just have look at below code
I have a file descriptor which will take input from a string as shown below.
printf FD1 "this my first line";
This will work with out any issue, but when you want to send multiple lines as shown below we have to use PERL here-docs as shown below.
printf FD1 << EOM;
other than this syntax, if you give any other thing it will fail. Observe that there is no double quotes before or after EOM and there is a ; colon after first EOM. We even have to remember that there should not be any space between << and EOM. Hope this helps some one who did this mistake.
This is an issue we will get for many reasons, one reason we get this error is when we try to use the partition which is already mounted or used in your machine. This occurs some times due to LVM which is not properly implemented
If you fee this is new partition and want to unlock the file from kernel follow below steps
Step1: Check what are the partitions known to the kernel by using proc file system as shown bleow
[root@gnani surendra]# cat /proc/partitions
major minor #blocks name
Q. How can I move all my files in my working directory to a sub-directory with the working directory? I am getting error "mv: cannot move `' to a subdirectory of itself," Can I move all the files/folder to sub-directory with out this error?
Yes, you can move all your files/folders present in your directory to a sub-directory with out getting that error. This error will occure when mv command try to move this sub-directory as well which it can not do and throws this error. All you have to do set shopt extglop option and try below command
Q. I am facing issue "isohybrid: Warning: more than 1024 cylinders: isohybrid: Not all BIOSes will be able to boot this devic", How can I resolve this?
First this is not an issue or error. This is just a warning not an error and it is just a warnning. This warning will be displayed when you are trying to convert a normal ISO file to hybrid ISO file by using isohybrid command
This error will come when your ISO file is more than 1GB size.
error: Requested operation is not valid: Disk does not support snapshot
This error arises when you try to take a snapshot of a VM hard disk with virsh command
as shown below
virsh snapshot-create Clusterbase
error: Requested operation is not valid: Disk '/path/to/kvm/clusterbase.img' does not support snapshot.
If you see image of this VM is .img format, by default Virsh snapshot will work only for qcow2 format as of time of this post writing. So first convert that image to qcow2 format and then try to do a snapshot t with same command.
Convert img file to qcow2 format
qemu-img convert -f raw -O qcow2 /path/to/kvm/clusterbase.img /path/to/kvm/clusterbase.qcow2
This error will come when you are trying to save VM using virsh command. When you try to save VM status using Virt-manager we no need to mention any file to save the status. Virt-manager will take care of saving it. But virsh have no mechanism like this. We have to provide a file to save the machine status.