Introduction

fdisk

[root@racnode1 ~]# fdisk /dev/hdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.


The number of cylinders for this disk is set to 4865.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-4865, default 1): 1
Last cylinder or +size or +sizeM or +sizeK (1-4865, default 4865): 4865

Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): 83

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

Create ext3 File System

[root@racnode1 ~]# mkfs.ext3 -b 4096 /dev/hdb1
mke2fs 1.27 (8-Mar-2002)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
4889248 inodes, 9769520 blocks
488476 blocks (5.00%) reserved for the super user
First data block=0
299 block groups
32768 blocks per group, 32768 fragments per group
16352 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000, 7962624

Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

Mounting the File System

You will first need to create the /db directory before mouting the disk! (e.g. mkdir /db)

LABEL=/                 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /proc                   proc    defaults        0 0
none                    /dev/shm                tmpfs   defaults        0 0
/dev/hdb1               /db                     ext3    defaults        1 1
/dev/hda2               swap                    swap    defaults        0 0
/dev/cdrom              /mnt/cdrom              iso9660 noauto,owner,kudzu,ro 0 0
/dev/fd0                /mnt/floppy             auto    noauto,owner,kudzu 0 0

[root@racnode1 ~]# mount /db

[root@racnode1 ~]# df -k
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda3             37191660  11016692  24285724  32% /
/dev/hda1               101089     12130     83740  13% /boot
none                    515524         0    515524   0% /dev/shm
/dev/hdb1             38464340     32828  36477608   1% /db

If dma is enabled on a controller that is not well supported, these errors can appear. ( I had it on a VIA KT266a with kernel 2.2. Upgrading to kernel 2.4 fixed it beautifully.

If you are sure that the IDE controller is supported, the drive is on its way out. You can run fsck with the badblock option turned on to mark these blocks as bad... As a rule, once these errors start, we throw the disk away(This is a high availability production environment).

If you dont mind that the disk can crash in the near future, make a backup and continue using it, it might work for a long time to come.

If the disk is under guarantee... take it back, it is not worth risking data loss if the drive can be replaced for free.

This is how you hunt for and fix badblocks.

# e2fsck -c /dev/hda1

Make sure that you have a backup, badblock scans can destroy data running with certain switches.

# man badblocks && man e2fsck (And read them carefully)

To turn of dma per drive

# hdparm -d0 /dev/hd[a-d]

To list dma settings

# hdparm -d /dev/hd[a-d]

To turn dma on

# hdparm -d1 /dev/hd[a-d]

Where hd[a-d] is hda, hdb, hdc, hdd.

sudo usermod -a -G sudo hduser

sudo update-alternatives --config editor

Here's How:

1. To capture the entire desktop, press Command-Shift-3. The screen shot will be automatically saved as a PNG file on your desktop.
2. To copy the entire desktop, press Command-Control-Shift-3. The screen shot will be placed on your clipboard for you to paste into another program.
3. To capture a portion of the desktop, press Command-Shift-4. A cross-hair cursor will appear and you can click and drag to select the area you wish to capture. When you release the mouse button, the screen shot will be automatically saved as a PNG file on your desktop. (The file is saved as PDF in Mac OS 10.3 and earlier.)
4. To capture a specific application window, press Command-Shift-4, then press theSpacebar. The cursor will change to a camera, and you can move it around the screen. As you move the cursor over an application window, the window will be highlighted. The entire window does not need to be visible for you to capture it. When you have the cursor over a window you want to capture, just click the mouse button and the screen shot will be saved as a PNG file on your desktop. (The file is saved as PDF in Mac OS 10.3 and earlier.)
5. Add Control to the two shortcuts above to place the screen shot on the clipboard instead of saving it to the desktop.
6. Another method for capturing screen shots in Mac OS X is by using the bundled Apple utility, Grab, located in the Applications > Utilities folder. Grab is useful if you need to include a cursor or a menu in your screen shot, or if you want to save your screen shot to TIFF format. To include a cursor, first go to Grab Preferences and select the cursor icon you wish to have in your screen shot. To capture the screen with Grab, run Grab, then choose of the capture modes from the "Capture" menu: Selection, Window, Screen, Timed Screen.
7. When you choose the Selection mode in Grab, you can capture a specific region of the screen by dragging around it. Grab will display a tooltip showing the size of the region you have selected and the screen shot will open in a window when you release the mouse button. The cursor will not be included.
8. When you choose the Window mode in Grab, an instruction window will appear asking you to select the window you wish to capture, then click the "Choose Window" button. When you click the button, the instructions will disappear and the window you click ill be captured, including the mouse cursor at the position where you click (if a cursor was selected in Preferences).
9. When you choose the Screen mode in Grab, an instruction window will appear asking you to click the screen when you are ready to capture. The mouse cursor will be included in your screen shot at the position where you click (if a cursor was selected in Preferences).
10. When you choose the Timed Screen mode in Grab, an instruction window will appear, allowing you to prepare your screen for capture. When you are ready, press the "Start Timer" button and you will have ten seconds before the screen is captured. This allows you to open menus and sub-menus, if necessary. After ten seconds the entire screen will be captured. The mouse cursor will be included in your screen shot if a cursor was selected in Preferences.