Cisco UCS Server Hardware Configuration for MUR Applications

 

 

This section describes procedures for configuring a Cisco UCS server running a custom Red Hat Enterprise Linux (RHEL) operating system. These procedures are for Mobility Unified Reporting System (MUR) applications only.

 

Overview

Important: This document is specific to MUR applications. For all other applications, please refer to the official UCS Server documentation.

This section explains two procedures: disk partition and creating an XFS file system. Disk partitioning is carried out as part of the RHEL OS installation. The XFS file system is configured afterwards.

 

Prerequisites

The following are prerequisites for this configuration:

 

•	Cisco UCS 460-1 server with multiple hard disks.

•	MegaRAID Controller.

•	ISO for the RHEL OS.

 

Storage Recommendations

The following are recommendations for this configuration:

•	Separate storage (either a single disk or RAID array for the OS (root and swap space partitions).

•	Two RAID arrays: RAID-0 for the MUR application and RAID-5 for the Postgres database.

•	LVM: separate physical volume and volume groups for the three RAID array disk groups.

•	XFS file system:

•	Block size = 4KB.

•	S-unit in terms of RAID strip size = 256KB

•	S-width in terms of span of disks in the RAID array.

Important: The rest of this section assumes the RAID arrays have already been configured per the above recommendations.

 

Disk Partitioning

Follow these steps to partition a disk.

 

1.	Start the RHEL installation. The Disk Partitioning screen opens showing the two available drives. These are the RAID arrays configured earlier.

2.	Select both drives. Ensure the default option to remove Linux partitions on selected drive and create default layout is selected.

3.	Select the Review and Modify Partitioning Layout checkbox. Press Next.

4.	Press Yes to confirm the edits are required. Press Next to open the Volume Groups and Partitions configuration screen as depicted below:

 

Creating Volume Groups and Partitions

Follow these steps to create the volume groups and partitions based on the following table:

Volume Groups and Partitions Data

Partition	Space (GB)	Logical Volume	File-System	Mount Point
VolGroup00 (on drive with RAID-0)
Root (RHEL OS)	100	LogVol100	ext3	‘/’
Swap Space	32	LogVol01	Swap	-
VolGroup01 (on drive with RAID-0
MUR Application	All remaining space on Volume Group	LogVol00	ext3	/apps
VolGroup02 (on drive with RAID-5
Database (Postgres data directory)	All the space in the Volume Group	LogVol00	ext3	/db

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In the Disk Partition Screen (depicted below) the default configuration combines all the disks into a single volume group (VolGroup00) having two logical volumes LogVol00 and LogVol01 for ‘/’ and Swap partitions respectively. These default partitions have to be deleted.

 

1.	Select VolGroup00 and press the Edit button to re-configure the volume group and its logical volumes (partitions). The Edit screen opens as depicted below:

2.	Delete the the default logical volumes (partitions for '/' and Swap) from the bottom window.

3.	In the Physical Volumes to Use window, select the drive configured with RAID-0 for the OS installation.

4.	Press the Add button and configure a partition for Swap using parameters defined in the table provided earlier.

5.	Press the Add button and configure a partition for / using parameters defined in the table provided earlier:

6.	Verify the new Logical Volumes are configured as required and press the OK button to set the configuration.

7.	Click the LVM Volume Groups entry to create a new Volume Group for the MUR Application and Postgres Database partitions. Create these with the name VolGroup01 and VolGroup02 respectively.

8.	In the Physical Volume to Use field, select the drive configured with RAID-0 and create a Volume Group with the MUR Application as detailed in the table and press the Add button.

9.	Use the last physical volume to create the Volume Group for the Postgres Database as detailed in the table and press the Add button.

10.	Press OK to display the updated Volume Groups screen. Check this detail against the correct information in the table if required.

11.	Press Next to finish the RHEL installation then reboot the system.

 

Configuring the XFS File System

The LVM configuration you just performed created all the partitions with an EXT file system. An XFS file system can be fine-tuned to work with a RAID array. To configure the XFS file system parameters for stripe-unit and stripe-width you must know the RAID information (stripe size and span of disks) for the respective drives. These values have to be provided in terms of 512 byte blocks.

We suggest you use su (stripe-unit) and sw (stripe-width) to avoid confusion when setting the following values:

 

•	su = RAID controller stripe size in Bytes or KBytes

•	sw = The span of the physical data disks excluding the number of duplicate disks for RAID10 and parity disks for RAID5 and RAID6.

Follow these steps to configure the MUR application (/apps) and Postgres (/db) partitions with an XFS file system. In this example, these settings are for four (4) disks of RAID-0 and seven (7) disks of RAID-5.

 

1.	Un-mount the partitions using the umount command:

$ umount /apps

$ umount /db

2.	Create the XFS file system using the mkfs.xfs command:

$ mkfs.xfs -f -b size=4096 -d su=256k,sw=4 /dev/mapper/VolGroup01-LogVol00

$ mkfs.xfs -f -b size=4096 -d su=256k,sw=6 /dev/mapper/VolGroup02-LogVol00

3.	Re-mount the partitions using the mount command:

$ mount -t xfs /dev/mapper/VolGroup01-LogVol00 /apps

$ mount -t xfs /dev/mapper/VolGroup02-LogVol00 /db

4.	Update the /etc/fstab file to reflect the updated configuration.

5.	Open the /etc/fstab file and change the file system type for the /apps and /db partitions to XFS. The correct entries should be as follows:

/dev/VolGroup01/LogVol00 /apps xfs defaults 1 2

/dev/VolGroup02/LogVol00 /apps xfs defaults 1 2

 

 

 

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