[parted-devel] Parted 3.1.90 Testing with DMRAID on Debian 8 Jessie (Testing)

[Curtis Gedak]

My apologies for the first post.  I seem to have pasted a copy of the 
post within itself.

The post should read as follows:

Following are my DMRAID test results on a Debian Testing Virtual Machine.

Test Setup:
   Debian 8 Jessie Testing (updated to latest packages)
   Parted 3.1.90
   GParted 0.19.1 configured with: --enable-libparted-dmraid
                              and  --enable-online-resize

1)  Create two 1 GB disks in Virtual Machine (sdc and sdd)

2)  Create Intel Software RAID

# dmraid -f isw -C MyRaid1 --type 1 --disks /dev/sdc,/dev/sdd

3)  Reboot

4)  List dmraid device paths

# ls -l /dev/mapper
total 0
crw------- 1 root root  10, 236 Jul 26 10:57 control
brw-rw---- 1 root disk 254,   0 Jul 26 10:57 isw_ebcdedbibh_MyRaid1

5)  Run GParted, create msdos partition table, create 128 MiB
     ext4 partition, and apply operations.

     SUCCESS!

     GParted works correctly with newly created
     isw_ebcdedbibh_MyRaid1p1 partition and reads the file system usage
     details.

6)  List dmraid device paths

# ls -l /dev/mapper
total 0
crw------- 1 root root  10, 236 Jul 26 10:57 control
brw-rw---- 1 root disk 254,   0 Jul 26 10:59 isw_ebcdedbibh_MyRaid1
lrwxrwxrwx 1 root root        7 Jul 26 11:00 isw_ebcdedbibh_MyRaid1p1 -> 
../dm-1
# ls -l /dev/dm-*
brw-rw---- 1 root disk 254, 0 Jul 26 10:57 /dev/dm-0
brw-rw---- 1 root disk 254, 1 Jul 26 11:00 /dev/dm-1

7)  Reboot

8)  List dmraid device paths

# ls -l /dev/mapper
total 0
crw------- 1 root root  10, 236 Jul 26 11:02 control
brw-rw---- 1 root disk 254,   0 Jul 26 11:02 isw_ebcdedbibh_MyRaid1
brw-rw---- 1 root disk 254,   1 Jul 26 11:02 isw_ebcdedbibh_MyRaid11

     NOTE:  Missing 'p' in partition device path.

9) Start GParted.
     GParted cannot read partition details.
     Suspected reason:
     isw_ebcdedbibh_MyRaid1p1  <-- what libparted expects
     isw_ebcdedbibh_MyRaid11   <-- what dmraid actually created

To summarize, parted-3.1.90 fixes a previous problem with creating the
partition device entry in /dev/mapper.

However, there still appears to be a disconnect between the naming
method used by the dmraid package, versus the normal naming standard
used by libparted.

Current dmraid package partition naming method:
   Always append partition number to device name.

Parted 3.1.90 normal partition naming standard:
   If device name ends in a letter
     then append partition number to device name
   Else if device name ends in a number
     then append 'p' plus the partition number to device name

 From my experience the naming standard used by parted 3.1.90 is the
commonly used naming standard by GNU/Linux.  The dmraid partition
naming method is non-standard.

Please let me know if you require additional dmraid testing.

Regards,
Curtis