This was a surprising bug but I unplugged all drives for an array md127. At first it was just 1 drive and mdadm seemed to notice this. I unplugged the second drive taking the array offline but mdadm did not realize it was offline and still showed a non-existent disk as being part of it. This created problems trying to unmount it or even to stop this array with mdadm freezing.
As for how to fix it I can only think of making sure you are not in a mounted path of........
I've only ever seen this in Ubuntu for some reason and it is because of the /etc/nsswitch.conf settings.
So the issue is that if the hostname's reverse DNS cannot be found that you need to go back to DNS which was not the default in this nsswitch.conf file for some strange reason.
Edit /etc/nsswitch.conf and replace your "hosts" line with this:
#hosts: files dns mdns4_minimal [NOTFOUND=return] mdns........
This server was experiencing loads of up to 80 and maxing out the RAM and kmemsize on a CPanel VPS. There were literally dozens if not hundreds of exim processes. I have no idea why exim has such a design that would allow it to consume this much CPU and RAM. Any normal MTA should not be spawning so many processes, it should be processing them in sequence and if it is going to spawn hundreds of processes in response to a large volume of mail, it's better to have a delayed del........
If you have the "(auto-read-only)" beside an arrayI have no idea why that happens but it is easy to fix.
Just run "mdadm --readwrite /dev/md1" (rename md0 to the device with the problem and it will begin to resync.
md1 : active (auto-read-only) raid1 sdb2[0] sda2[1]
19534976 blocks [2/2] [UU]
resync=PENDING
........
I've tried to find a good sensible solution to cluster with and each technology has it's pros and cons and there is no perfect solution and I've found a lot of "exaggerations" in the applications, benefits and performance of these different filesystems.
DRBD
I first started off with DRBD and Ihave to say it does live up to the hype, is quite reliable (although it can be annoying to match up the kernel module and user applications since they must match and whe........
This is really something the SSHServer developers should consider. The cause of this annoyance is because of failed DNS lookups on your IPaddress, which is especially common for many dedicated/col-located servers and also computers on internal NAT/private networks.
The chances are this is the cause of your SSHSlow/Delayed Login problems.
The easy solution to SSH Login Problems
Edit /etc/ssh/sshd_config
Add this line to disable r........