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

Procedure 22.1. Bringing a disk online

  1. 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
  2. Next, check to see if it is already online:
    # cat online
    0
  3. If it is not online, run the following command to bring it online:
    # echo 1 > online
    # cat online
    1
  4. 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.
As an alternative, the recommended method for bringing a disk online (automatically) is to use the following simple command:
# chccwdev -e 4b2e
Once the disk is online, 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.