My Linux notes --

Disable Network Managers system-ca-certs to connect to wpa2 Ent. not using /wout cert in Arch Linux.

1) Comment out system-ca-certs =true in

#vim /etc/NetworkManager/systemconnections/<ssid>

 

Remap CapLock key to Shift Gnome 3

I can not stand the Caps Lock key. I tend to press the Caps Lock key when I intend to press the shift key. Thankfully there is an easy to remap this key in Gnome 3. This can also be used in KDE with slight modifications.

First, remap the Caps Lock key using xmodmap:

$ xmodmap -e "keycode 66 = Shift_L NoSymbol Shift_L"

Next export your current key mapping to .xmodmap

$ xmodmap -pke > .xmodmap


That is it. If you need to revert the Caps_Lock key back you can run the following command.

$ xmodmap -e "keycode 66 = Cap_Lock NoSymbol Caps_Lock"

Extend LVM and filesystem on RHEL 6

If disks have been added when the system is running you will need have the kernel scan for new drives by running.


#'for i in `ls -1 /sys/class/scsi_host/`; do echo "- - -" > /sys/class/scsi_host/$i/scan;

Next run dmesg to get the name of the device.

 #dmesg
 scanning ...
 scsi 0:2:2:0: Direct-Access     DELL     PERC H700        2.10 PQ: 0 ANSI: 5
 sd 0:2:2:0: Attached scsi generic sg0 type 0
 sd 0:2:2:0: [sde] 875298816 512-byte logical blocks: (448 GB/417 GiB)
 sd 0:2:2:0: [sde] Write Protect is off
 sd 0:2:2:0: [sde] Mode Sense: 1f 00 00 08
 sd 0:2:2:0: [sde] Write cache: enabled, read cache: enabled, doesn't support    DPO or FUA
  sde: unknown partition table
  sd 0:2:2:0: [sde] Attached SCSI disk
  scsi 0:0:0:0: Direct-Access     ATA      Crucial_CT960M50 MU02 PQ: 0 ANSI: 5
  scsi 0:0:1:0: Direct-Access     SEAGATE  ST91000640SS     AS03 PQ: 0 ANSI: 6
  scsi 0:0:2:0: Direct-Access     SEAGATE  ST91000640SS     AS03 PQ: 0 ANSI: 6
  scsi 0:0:3:0: Direct-Access     SEAGATE  ST91000640SS     AS03 PQ: 0 ANSI: 6
  scsi 0:0:4:0: Direct-Access     ATA      Crucial_CT960M50 MU02 PQ: 0 ANSI: 5
  ...
You can verify you device with the following command.

#fdisk -l /dev/sde 

   Disk /dev/sde: 448.2 GB, 448152993792 bytes
  255 heads, 63 sectors/track, 54484 cylinders
  Units = cylinders of 16065 * 512 = 8225280 bytes
  Sector size (logical/physical): 512 bytes / 512 bytes
  I/O size (minimum/optimal): 512 bytes / 512 bytes
  Disk identifier: 0x00000000
 ~                        

Next you can view the current volume group as shown below.

# vgs
 VG         #PV #LV #SN Attr   VSize   VFree  
 VolGroup00   1   3   0 wz--n- 476.25g 256.00m
 VolGroup01   1   1   0 wz--n-   4.55t 507.79g

Now we will create a physical volume on /dev/sde
# pvcreate /dev/sde    
Physical volume "/dev/sde" successfully created  

 Then you will need to add the Physical Volume to the Volume Group.

 # vgextend VolGroup00 /dev/sde
   Volume group "VolGroup00" successfully extended

Now the vgs command show that our Volume Group has been extended.

 # vgs     

   VG         #PV #LV #SN Attr   VSize   VFree    

   VolGroup00   2   3   0 wz--n- 893.59g 417.59g  

   VolGroup01   1   1   0 wz--n-   4.55t 507.79g

 Now you can view the Logical Volume that needs to be extended.

   

 #  lvs   

   LV       VG         Attr      LSize   Pool Origin Data%  Move Log Cpy%Sync    Convert   

   LogVol00 VolGroup00 -wi-ao---  12.00g                                                

   LogVol01 VolGroup00 -wi-ao---   1.00g                                                

   LogVol02 VolGroup00 -wi-ao--- 463.00g                                                

   LogVol00 VolGroup01 -wi-ao---   4.05t

Then we can exttend the Logival Volume by running the following

# lvresize -L 830g /dev/VolGroup00/LogVol02   

     Extending logical volume LogVol02 to 830.00 GiB

       Logical volume LogVol02 successfully resized

  

 I like to vie my changed to insure every thing worked as I hoped.

# lvs

   LV       VG         Attr      LSize   Pool Origin Data%  Move Log Cpy%Sync    Convert  

     LogVol00 VolGroup00 -wi-ao---  12.00g                                               

     LogVol01 VolGroup00 -wi-ao---   1.00g                                               

     LogVol02 VolGroup00 -wi-ao--- 830.00g                                               

     LogVol00 VolGroup01 -wi-ao---   4.05t                    

 ~                                                         

 All that is left is to extend our file system.with the command:

 # resize2fs  /dev/VolGroup00/LogVol02

 resize2fs 1.41.12 (17-May-2010)  

 Filesystem at /dev/VolGroup00/LogVol02 is mounted on /var/lib/mysql_ssd; on-    line resizing required

 old desc_blocks = 29, new_desc_blocks = 52

 Performing an on-line resize of /dev/VolGroup00/LogVol02 to 217579520 (4k)      blocks.

 The filesystem on /dev/VolGroup00/LogVol02 is now 217579520 blocks long.

All done.