EVMS (Partitions & Psudo-Quotas)
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Important Note
The evms gui utility doesn't like iso files mounted as partitions. The OES installation cd rom iso images have been mounted on the server so I don't have to piss around changing cds all the time.
evms gui will ask you if you'd like to mount loop0, loop1, etc. YOU MUST SAY NO!!! Let evms gui try and mount the images the server will panic and crash horribly.
Increase Space for a Partition
NOTE: X11 forwarding as the root user on Ares appears to be broken- however the evms ncurses utility is still accessable (as is yast2) instead of using evmsgui, use evmsn Running evmsgui with sudo rights doesn't work as it relies on being run as root to invoke additional components
Login as root
ares:~# startx
Get a graphical desktop going, and open an xterm (probably need to right or left click the desktop and select xterm).
ares:~# evmsgui
to launch a GUI administration program for dealing with partitions.
Right click a partition and select Expand... to increase the size. You will need to click Next and then enter the additional space required for the partition. Continue through the wizard using the Next buttons. Finally click the save icon on the main EVMS window to apply the setting.
Reducing Space Used by a Partition
Although there is a Shrink option on the context menu for each partition don't use it. There are warnings of potential problems with data loss when you shrink a partition and up to this point, no one here has tested it out yet!
You must backup the data. Either move it off to a USB harddisk, copy it to another partition with pleanty of slack. Don't rely on there being a recent tape backup of the data because the tape drive is a bit moody.
The problems with data loss are probably for stupid people who think you can take a 10GB partition with 10GB of data and shrink it. (You did consider the size of the remaining data and overhead for the filesystem didn't you? ;-). It's worth a go, but like I said, so far it's untested.
New Partitions
Naming Convetion is based on the mount point for the partition: /srv/www/online/area/maths is known as online-area-maths. Just make sure it's something that you can figure out the correct mount point from. Don't mix up the partition name with the volume label!
Unless by some mirical we are able to create NSS partitions, we need a compatibility partition, formatted with reiserfs.
You need to edit the /etc/fstab file and create the mount point manually. The evmsgui program kind of makes you think it's going to take care of it but doesn't!
Desired mount point (for e.g.) /srv/www/online/area/basketweaving Partition Name: online-area-basketweaving Label: basketweaving (doesn't matter really what you make the label)
ares:~# mkdir /srv/www/online/area/basketweaving ares:~# vi /etc/fstab
/dev/evms/lvm/system/online-area-basketweaving /srv/www/online/area/basketweaving reiserfs acl,user_xattr,noatime 1 2
That last line needs to be entered at the bottom of the /etc/fstab file. Read up on:
Standard Partitions
Standard partitions must be managed with EVMS. The OES installation will not setup fstab correctly. There may be a post-install update for yast but you'd better check the fstab after altering standard partitions.
In order to have EVMS manage the partitions simply edit the device path, replace /dev/ with /dev/evms/. E.g. /dev/sda2 becomes /dev/evms/sda2
