Raid volumes on CPM explained

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Article ID: 168116

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Updated On:

Products

XOS

Issue/Introduction

Presents the partition layout and configuration when RAID is enabled on the CPM.N/A

Resolution

CPM-8600 and above can be equipped with more than one disk.

CPM partitions can be configured as follows:
- non-RAID when single hard drive is installed
- RAID-1 is configured by default on systems equipped with two hard drives. RAID-1 may be seen on systems with only one active hard drive (if the second drive fails)
- RAID-0 is only available on systems with two hard drives.

Crossbeam XOS uses Linux software, RAID and a number as well as size of partitions in case of RAID-1 configuration is the same as in case of non-RAID system as explained in solution#1209.

All RAID partitions are named as /dev/mdX devices and mapped to relevant partitions on hard drive. 



There are three ways to verify the RAID configuration of a system (RAID-0 or RAID-1)

1). From XOS CLI, by running command:
show module status <cp1|cp2>

This will show status of the module cp1|cp2 including raid status and type:

###
[cut]
RAID Status Active, RAID 1
[cut]


2).  From XOS CLI, by running command:
# show module status <cp1|cp2> disk
NA = Not Available, DP = Data Plane, CP = Control Plane
cp = Control Processor, ap = Application Processor, np = Network Processor


Slot 14:
Hard Disk 100(GB)
Second Hard Disk 100(GB)
Flash N/A
Hard Drive Error None
Second Hard Drive Error None
RAID Status Active, RAID 1


3).  Directly from shell level by checking /proc/mdstat

### below example shows system booted from second partition set
[CPMROOT]# cat /proc/mdstat
Personalities : [raid0] [raid1]
read_ahead 1024 sectors
Event: 21
md9 : active raid1 sdb9[1] sda9[0]
104320 blocks [2/2] [UU]

md10 : active raid1 sdb10[1] sda10[0]
1003904 blocks [2/2] [UU]

md11 : active raid1 sda11[0] sdb11[1]
1003904 blocks [2/2] [UU]

md12 : active raid1 sdb12[1] sda12[0]
8008256 blocks [2/2] [UU]

md13 : active raid1 sdb13[1] sda13[0]
28001152 blocks [2/2] [UU]
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How to Verify the Partition Type

RAID partitions should be marked on the hard drive level as RAID-1 when RAID is created.

The type of partition is shown as last column of the below command:
# fdisk -l <hard drive device>


[CPMROOT]# fdisk -l /dev/sda

Disk /dev/sda: 255 heads, 63 sectors, 12161 cylinders
Units = cylinders of 16065 * 512 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 fd Linux raid autodetect
/dev/sda2 14 12161 97578810 5 Extended
/dev/sda5 14 138 1004031 fd Linux raid autodetect
/dev/sda6 139 263 1004031 fd Linux raid autodetect
/dev/sda7 264 1260 8008371 fd Linux raid autodetect
/dev/sda8 1261 4746 28001263+ fd Linux raid autodetect
/dev/sda9 4747 4759 104391 fd Linux raid autodetect
/dev/sda10 4760 4884 1004031 fd Linux raid autodetect
/dev/sda11 4885 5009 1004031 fd Linux raid autodetect
/dev/sda12 5010 6006 8008371 fd Linux raid autodetect
/dev/sda13 6007 9492 28001263+ fd Linux raid autodetect

[CPMROOT]# fdisk -l /dev/sdb

Disk /dev/sdb: 255 heads, 63 sectors, 12161 cylinders
Units = cylinders of 16065 * 512 bytes

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 13 104391 fd Linux raid autodetect
/dev/sdb2 14 12161 97578810 5 Extended
/dev/sdb5 14 138 1004031 fd Linux raid autodetect
/dev/sdb6 139 263 1004031 fd Linux raid autodetect
/dev/sdb7 264 1260 8008371 fd Linux raid autodetect
/dev/sdb8 1261 4746 28001263+ fd Linux raid autodetect
/dev/sdb9 4747 4759 104391 fd Linux raid autodetect
/dev/sdb10 4760 4884 1004031 fd Linux raid autodetect
/dev/sdb11 4885 5009 1004031 fd Linux raid autodetect
/dev/sdb12 5010 6006 8008371 fd Linux raid autodetect
/dev/sdb13 6007 9492 28001263+ fd Linux raid autodetect

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Workaround

N/A