Every file is a hard link. It is a label or name assigned to a set of information which resides on the hard disk. In most of the cases there is a single name assigned to a file (a single hard link).
I it possible however to create different names which all refer to the same content.
Why you would do that? There are various reasons.
Some quick examples:
- backups that keep various versions of your data can use hard links for files with the content unchanged.
For several month I had this problem on one of my osx servers: the computer name was keep changing by adding a number at the end. Today was mmd (1), tomorrow mmd (2) and so on.
I have tried several things but nothing was successful until I finally gave up and looked up over the internet.
The solution was found here (link at the end of this article), among other methods. The one below was the most useful to me.
Create RAID 1 with missing volume (will destroy the data on the volume):
[osx@mini Volumes]$ diskutil appleRaid create mirror vbox JHFS+ disk2s2
Started RAID operation
Unmounting proposed new member disk2s2
Adding a booter for the RAID partition disk2s2
Creating a RAID set
Bringing the RAID partitions online
Waiting for the new RAID to spin up "2134725A-668E-45C3-BBD6-AAD5FF4D1991"
Initialized /dev/rdisk10 as a 477 GB case-insensitive HFS Plus volume with a 40960k journal
No matter the monitorization solution, CPU utilization is important but if you really want to know what is happening with your system, you should look at load average. I will explain below why.
The current CPU utilization does not reflect the actual load of the system because when a host is heavily loaded, its CPU usage doesn't have to be necessary close to or at 100%.
Furthermore, the CPU utilization tends to generate (in monitoring tools) a significant number of false alerts, even if the percentage alert is close to 100%. Explanation follows.
Do you use Transmission?
If yes, I suggest you check your version and update it soon. There are reports that a specific version has been tampered with.
Over the weekend, the first instance of Mac ransomware was found in a malicious update to the Transmission BitTorrent client. Version 2.90 of Transmission downloaded from the Transmission website was infected with "KeRanger" ransomware.
It is simple and that is why I will be very straight.
The configuration file for grub2 is /boot/grub/grub.cfg, but you do not have to edit that file directly because it is generated by update-grub command and you will loose all your modification on next update.
Many times you can find difficult to perform simple tasks if you do not have the appropriate documentation, or you are not searching it correctly :)
It happened to me the other day: I had to rename a vm in Citrix Xen without XenCenter. After few readings, I discovered!
I know, you have XenCenter and everything is easily done from there.
But what happens if you are not able to use it? Time to fire up the command line :)
In the example below, we will change the memory from 256M to 1G.
Citrix Xen has a way to migrate the machines from one host to another via xe vm-export and xe vm-import commands but there are situations when this won't work.
For example, if the source disk is in bad shape and there are bad (unreadable) blocks on your vm's disks, the xe vm-export command will be unsuccessful with the following error:
I was forced the other day to shutdown a machine via command line and my surprise was to get an error during the execution: VM didn't acknowledge the need to shutdown.
The error is quite convincing and full of useful stuff (NOT) but it's there and you cannot get past it without some extra parameters.
Read on for the solution.
I don't remember exactly when I have installed rEFIt (I did it only once) but I know I am using it without any problems since around 2006 and it went trough 2 laptops and several OSX versions already. The beauty of OSX upgrades and Time Machine.
After installing El Capitan, I was still using it without problems (well, just a small one but no biggie - will be mentioned a bit later), but also with SIP enabled! Will explain about SIP too.