At Thu, 25 Jun 2015 11:03:18 -0400 CentOS mailing list centos@centos.org wrote:
On Wed, June 24, 2015 16:11, Chuck Campbell wrote:
Is there an easy to follow "howto" for normal LVM administration tasks. I get tired of googling every-time I have to do something I don't remember how to do regarding LVM, so I usually just don't bother with it at all.
I believe it has some benefit for my use cases, but I've been reticent to use it, since the last time I got LVM problems, I lost everything on the volume, and had to restore from backups anyway. I suspect I shot myself in the foot, but I still don't know for sure.
At the risk of some ridicule I suggest that you look at installing Webmin. It is a web based system administration tool that I find invaluable. The two most common complaints I encounter when I discuss its merits are 'security' and 'transparency'.
The security issue is trivially dealt with. Install Webmin and configure it to listen on 127.0.0.1 using its standard port TCP10000. Install Firefox on the same host and then run firefox from an 'ssh -Y' session using the --noremote option. If you are totally paranoid then firewall TCP10000 as well, configure Webmin to use https only, and then only start the webmin service when you are performing maintenance.
There are less draconian measures that are in my opinion equally secure from a practical standpoint but I am sure that you can figure those out on your own.
The transparency issue is really unanswerable. There exists a school of thought that if you are going to administer a Linux system (or OS of the proponent's choice) then you should learn the command syntax of every command that you are called upon to use. This is the one-and-only path to enlightenment. Like upholding motherhood and promoting the wholesomeness of apple-pie this sort of moralizing really brooks no answer. You can guess my opinion on that line of puritanism.
HA! You only really need to learn *one* command: the man command. The man provides 'enlightenment' for all other commands:
man vgdisplay man lvdisplay man lvcreate man lvextend man lvresize man lvreduce man lvremove man e2fsck man resize2fs
These are the only LVM commands I use regularly (yes there a a pile more, but most are rarely used and a handful only used in startup/shutdown scripts or when rescuing) and I often end up use the man command to refresh my memory of the command options.
As you have painfully discovered, infrequently used utilities and commands are difficult to deal with. The process of learning, or relearning, the correct arcana is particularly noisome given the notorious inconsistency of syntaxes across different utilities and the spotty coverage of up-to-date documentation. Google can be a dangerous guide given the wide variation of practice across differing flavours of *nix and the widespread aversion to providing dates on writings. In consequence I consign transparency arguments and their proponents to the religious fanatic file. Nothing personal but there is no point in arguing belief systems.
Right, expecting a *web search* to give *correct* command documentation is problematical. Using the local system man pages often works better, since the man pages installed with the installed utilities will cover the *installed* version and not the version that might be installed on a *different* distro, etc.
If you want to get infrequently performed sysadmin tasks done reliably and with a minimum of fuss use something like Webmin and get on with the rest of your life.