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NOTE: CentOS Enterprise Linux 5 is built from the Red Hat Enterprise Linux source code. Other than logo and name changes CentOS Enterprise Linux 5 is compatible with the equivalent Red Hat version. This document applies equally to both Red Hat and CentOS Enterprise Linux 5.

22.5. Adding DASD

The following is an example of how to add a DASD volume:

Note

Make sure the device is attached or linked to the Linux system if running under VM.

CP LINK RHEL4X 4B2E 4B2E MR
DASD 4B2E LINKED R/W

Use the cd command to change to the /sys/ directory that represents that volume:

# cd /sys/bus/ccw/drivers/dasd-eckd/0.0.4b2e/
# ls -l
total 0
-r--r--r--  1 root root 4096 Aug 25 17:04 availability
-rw-r--r--  1 root root 4096 Aug 25 17:04 cmb_enable
-r--r--r--  1 root root 4096 Aug 25 17:04 cutype
-rw-r--r--  1 root root 4096 Aug 25 17:04 detach_state
-r--r--r--  1 root root 4096 Aug 25 17:04 devtype
-r--r--r--  1 root root 4096 Aug 25 17:04 discipline
-rw-r--r--  1 root root 4096 Aug 25 17:04 online
-rw-r--r--  1 root root 4096 Aug 25 17:04 readonly
-rw-r--r--  1 root root 4096 Aug 25 17:04 use_diag

Next, check to see if it is already online:

# cat online
0

If it is not online, run the following command to bring it online:

# echo 1 > online
# cat online
1

Verify which block devnode it is being accessed as:

# ls -l
total 0
-r--r--r--  1 root root 4096 Aug 25 17:04 availability
lrwxrwxrwx  1 root root    0 Aug 25 17:07 block -> ../../../../block/dasdb
-rw-r--r--  1 root root 4096 Aug 25 17:04 cmb_enable
-r--r--r--  1 root root 4096 Aug 25 17:04 cutype
-rw-r--r--  1 root root 4096 Aug 25 17:04 detach_state
-r--r--r--  1 root root 4096 Aug 25 17:04 devtype
-r--r--r--  1 root root 4096 Aug 25 17:04 discipline
-rw-r--r--  1 root root    0 Aug 25 17:04 online
-rw-r--r--  1 root root 4096 Aug 25 17:04 readonly
-rw-r--r--  1 root root 4096 Aug 25 17:04 use_diag

As shown in this example, device 4B2E is being accessed as /dev/dasdb.

Use the cd command to change back to the /root directory and format the device:

# cd
# dasdfmt -b 4096 -d cdl -f /dev/dasdb -l LX4B2E -p -y

cyl    97 of  3338 |#----------------------------------------------|   2%

When the progress bar reaches the end and the format is complete, use fdasd to partition the device:

# fdasd -a /dev/dasdb
auto-creating one partition for the whole disk...
writing volume label...
writing VTOC...
checking !
wrote NATIVE!
rereading partition table...

Next, make a file system on the new partition:

# mke2fs -j /dev/dasdb1
mke2fs 1.35 (28-Feb-2004)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
300960 inodes, 600816 blocks
30040 blocks (5.00%) reserved for the super user
First data block=0
19 block groups
32768 blocks per group, 32768 fragments per group
15840 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912

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

This filesystem will be automatically checked every 39 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

Mount the new file system:

# mount /dev/dasdb1 /opt
# mount
/dev/dasda1 on / type ext3 (rw)
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
none on /dev/shm type tmpfs (rw)
/dev/dasdb1 on /opt type ext3 (rw)

Add an entry to /etc/fstab so that the file system is mounted at IPL time:

# vi /etc/fstab
# cat /etc/fstab
LABEL=/                 /                       ext3    defaults
1 1
none                    /dev/pts                devpts  gid=5,mode=620
0 0
none                    /dev/shm                tmpfs   defaults
0 0
none                    /proc                   proc    defaults
0 0
none                    /sys                    sysfs   defaults
0 0
/dev/dasdb1             /opt                    ext3    defaults
1 2

Add the device to the option line for the dasd_mod in /etc/modprobe.conf Make sure to add the new device at the end of the list, otherwise it changes the device number : devnode mapping and file systems are not on the devices they used to be on.

# vi /etc/modprobe.conf
# cat /etc/modprobe.conf
alias eth0 qeth
options dasd_mod dasd=201,4B2E

Rerun mkinitrd to pick up the changes to modprobe.conf so that the device can be online and mountable after the next IPL:

Note that the example below has been modified slightly for readability and for printing purposes. Each line that ends with "(elf64-s390)" should be treated as one line with no spaces, such as /tmp/initrd.AR1182/lib/dasd_mod.ko(elf64-s390).

# cd /boot
# mv initrd-2.6.7-1.451.2.3.img initrd-2.6.7-1.451.2.3.img.old
# mkinitrd -v initrd-2.6.7-1.451.2.3.img 2.6.7-1.451.2.3
Looking for deps of module ide-disk
Looking for deps of module dasd_mod
Looking for deps of module dasd_eckd_mod         dasd_mod
Looking for deps of module dasd_mod
Looking for deps of module dasd_fba_mod  dasd_mod
Looking for deps of module dasd_mod
Looking for deps of module ext3  jbd
Looking for deps of module jbd
Using modules:  ./kernel/drivers/s390/block/dasd_mod.ko
./kernel/drivers/s390/block/dasd_eckd_mod.ko
./kernel/drivers/s390/block/dasd_fba_mod.ko ./kernel/fs/jbd/jbd.ko
./kernel/fs/ext3/ext3.ko
Using loopback device /dev/loop0
/sbin/nash -> /tmp/initrd.AR1182/bin/nash
/sbin/insmod.static -> /tmp/initrd.AR1182/bin/insmod
copy from
/lib/modules/2.6.7-1.451.2.3/./kernel/drivers/s390/block/dasd_mod.ko
(elf64-s390) to 
/tmp/initrd.AR1182/lib/dasd_mod.ko(elf64-s390)
copy from
/lib/modules/2.6.7-1.451.2.3/./kernel/drivers/s390/block/dasd_eckd_mod.ko
(elf64-s390) to 
/tmp/initrd.AR1182/lib/dasd_eckd_mod.ko
(elf64-s390)
copy from
/lib/modules/2.6.7-1.451.2.3/./kernel/drivers/s390/block/dasd_fba_mod.ko
(elf64-s390) to 
/tmp/initrd.AR1182/lib/dasd_fba_mod.ko
(elf64-s390)
copy from
/lib/modules/2.6.7-1.451.2.3/./kernel/fs/jbd/jbd.ko(elf64-s390) to 
/tmp/initrd.AR1182/lib/jbd.ko(elf64-s390)
copy from
/lib/modules/2.6.7-1.451.2.3/./kernel/fs/ext3/ext3.ko(elf64-s390) to 
/tmp/initrd.AR1182/lib/ext3.ko(elf64-s390)
Loading module dasd_mod with options dasd=201,4B2E
Loading module dasd_eckd_mod
Loading module dasd_fba_mod
Loading module jbd
Loading module ext3

Run zipl to save the changes to initrd for the next IPL:

# zipl -V
Using config file '/etc/zipl.conf'
Target device information
  Device..........................: 5e:00
  Partition.......................: 5e:01
  Device name.....................: dasda
  DASD device number..............: 0201
  Type............................: disk partition
  Disk layout.....................: ECKD/compatible disk layout
  Geometry - heads................: 15
  Geometry - sectors..............: 12
  Geometry - cylinders............: 3308
  Geometry - start................: 24
  File system block size..........: 4096
  Physical block size.............: 4096
  Device size in physical blocks..: 595416
Building bootmap '/boot//bootmap'
Building menu 'rh-automatic-menu'
Adding #1: IPL section 'linux' (default)
  kernel image......: /boot/vmlinuz-2.6.7-1.451.2.3 at 0x10000
  kernel parmline...: 'root=LABEL=/' at 0x1000
  initial ramdisk...: /boot/initrd-2.6.7-1.451.2.3.img at 0x800000
Preparing boot device: dasda (0201).
Preparing boot menu
  Interactive prompt......: disabled
  Menu timeout............: disabled
  Default configuration...: 'linux'
Syncing disks...
Done.

 
 
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