Lustre Configuration Example

This Lustre configuration example illustrates the configuration steps for a simple Lustre installation comprising a combined MGS/MDT, an OST and a client, where:

Variable	Setting	Variable	Setting
network type	TCP/IP	MGS node	node 10.2.0.1@tcp0
block device	/dev/sdb	OSS 1 node	oss1
file system	temp	clientnode	client1
mount point	/mnt/mdt	OST 1	ost1
mount point	/lustre

1. Define the module options for Lustre networking (LNET), by adding this line to the /etc/modprobe.conf file.

options lnet networks=tcp

2. Create a combined MGS/MDT file system on the block device. On the MDS node, run:

[root@mds /]# mkfs.lustre --fsname=temp --mgs --mdt /dev/sdb

This command generates this output:

     Permanent disk data:
Target:       temp-MDTffff
Index:        unassigned
Lustre FS:    temp
Mount type:   ldiskfs
Flags:        0x75
     (MDT MGS needs_index first_time update )
Persistent mount opts: errors=remount-ro,iopen_nopriv,user_xattr
Parameters: mdt.group_upcall=/usr/sbin/l_getgroups

checking for existing Lustre data: not found
device size = 16MB
2 6 18
formatting backing filesystem ldiskfs on /dev/sdb
     target name   temp-MDTffff
     4k blocks     0
     options       -i 4096 -I 512 -q -O dir_index,uninit_groups -F
mkfs_cmd = mkfs.ext2 -j -b 4096 -L temp-MDTffff -i 4096 -I 512 -q -O
dir_index,uninit_groups -F /dev/sdb
Writing CONFIGS/mountdata

3. Mount the combined MGS/MDT file system on the block device. On the MDS node, run:

[root@mds /]# mount -t lustre /dev/sdb /mnt/mdt

This command generates this output:

Lustre: temp-MDT0000: new disk, initializing
Lustre: 3009:0:(lproc_mds.c:262:lprocfs_wr_group_upcall()) \
temp-MDT0000: group upcall set to /usr/sbin/l_getgroups
Lustre: temp-MDT0000.mdt: set parameter \
group_upcall=/usr/sbin/l_getgroups
Lustre: Server temp-MDT0000 on device /dev/sdb has started

4. Create the OST. On the OSS node, run:

 [root@oss1 /]# mkfs.lustre --ost --fsname=temp --mgsnode= 10.2.0.1@tcp0 /dev/sdb

The command generates this output:

<pre>
     Permanent disk data:
Target:      temp-OSTffff
Index:       unassigned
Lustre FS:   temp
Mount type:  ldiskfs
Flags:       0x72
(OST needs_index first_time update)
Persistent mount opts: errors=remount-ro,extents,mballoc
Parameters: mgsnode=10.2.0.1@tcp

checking for existing Lustre data: not found
device size = 16MB
2 6 18
formatting backing filesystem ldiskfs on /dev/sdc
     target name    temp-OSTffff
     4k blocks      0
     options        -I 256 -q -O dir_index,uninit_groups -F
mkfs_cmd = mkfs.ext2 -j -b 4096 -L temp-OSTffff -I 256 -q -O
dir_index,uninit_groups -F /dev/sdc
Writing CONFIGS/mountdata

5. Mount the OST. On the OSS node, run:

root@oss1 /] mount -t lustre /dev/sdb /mnt/ost1

The command generates this output:

LDISKFS-fs: file extents enabled
LDISKFS-fs: mballoc enabled
Lustre: temp-OST0000: new disk, initializing
Lustre: Server temp-OST0000 on device /dev/sdb has started

Shortly afterwards, this output appears:

Lustre: temp-OST0000: received MDS connection from 10.2.0.1@tcp0
Lustre: MDS temp-MDT0000: temp-OST0000_UUID now active, resetting
orphans

6. Create the client (mount the file system on the client). On the client node, run:

root@client1 /] mount -t lustre 10.2.0.1@tcp0:/temp /lustre

This command generates this output:

Lustre: Client temp-client has started

7. Verify that the file system started and is working by running the UNIX commands df, dd and ls on the client node.

a. Run the df command:

[root@client1 /] df -h

This command generates output similar to

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/VolGroup00-LogVol00

7.2G 2.4G 4.5G 35% /

dev/sda1 99M 29M 65M 31% /boot

tmpfs 62M 0 62M 0% /dev/shm

10.2.0.1@tcp0

/temp 30M 8.5M 20M 30% /lustre

b. Run the dd command:

[root@client1 /] cd /lustre

[root@client1 /lustre] dd if=/dev/zero of=/lustre/zero.dat bs=4M

count=2

This command generates output similar to:

2+0 records in

2+0 records out

8388608 bytes (8.4 MB) copied, 0.159628 seconds, 52.6 MB/s

c. Run the ls command:

;[root@client1 /lustre] ls -lsah

This command generates output similar to:

total 8.0M

4.0K drwxr-xr-x 2 root root 4.0K Oct 16 15

27 .

8.0K drwxr-xr-x 25 root root 4.0K Oct 16 15

27 ..

8.0M -rw-r--r-- 1 root root 8.0M Oct 16 15

27 zero.dat