Building an OST using Ansible (Lustre 2.x)

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1 Editing the template (makeoss.j2)

• The template is, at this point in time, hard coded per file system
• Consider copying it for your file system instead of editing it.

2 Create the playbook

• Copy a playbook ending in makeosts.yml
• The playbook creates a script that will create and mount each OST (makeoss.ost$num.sh)
• It also creates a script (getfstablabels.sh) that will grep for the names of the new OSTs so you can add them to /etc/fstab

2.1 Editing the playbook

• Edit the hosts line to correspond to your target OSS
• Edit the number of the OST (you want them to count up across the entire lustre filesystem) in THREE PLACES:
  • task name
  • dest line
  • variable name in with_items
• Consider doing these edits using the replace function

3 Create or add to the host-vars file

• variable osts is used by the template that makes getfstablabels.sh. It is a list of the devices
• each ost$num variable gives:
  • the device (same as in osts, sadly redundant)
  • the index (which must count up from zero across the whole file system)
  • the mount point (for which we use the numbering scheme ost$ossnum-$ostnum)

3.1 Here's a sample variable definition

ost7:
  - { device: /dev/sda, index: 6, mtpnt: /export/lard/ost2-1 }  

4 Run the playbook

caligirl;)~/infrastructure/ansible<1044>ansible-playbook -i inventories/lard playbooks/lardoss2makeosts.yml 

5 Run the scripts the playbook generates

5.1 If this is not your first go-round with the OSTs...

• You should make sure you have no partitions and delete the mount points

5.2 Run the makeoss scripts one at a time...

• Since making a mount point and mounting a directory do not include any output when they exit 0, the scripts use set -x

[root@lard-oss-2 Lustre]# sh makeoss.ost7.sh 

+ mkfs.lustre --index=6 --reformat --fsname=lard '--mkfsoptions=-E stride=32,stripe-width=224 -m0' --ost --mgsnode=10.7.17.126@o2ib0 /dev/sda

   Permanent disk data:
Target:     lard:OST0006
Index:      6
Lustre FS:  lard
Mount type: ldiskfs
Flags:      0x62
              (OST first_time update )
Persistent mount opts: errors=remount-ro
Parameters: mgsnode=10.7.17.126@o2ib

device size = 53412576MB
formatting backing filesystem ldiskfs on /dev/sda
   target name  lard:OST0006
   4k blocks     13673619456
   options        -m0 -J size=400 -I 256 -i 1048576 -q -O extents,uninit_bg,dir_nlink,quota,huge_file,64bit,flex_bg -G 256 -E stride=32,stripe-width=224,lazy_journal_init -F
mkfs_cmd = mke2fs -j -b 4096 -L lard:OST0006  -m0 -J size=400 -I 256 -i 1048576 -q -O extents,uninit_bg,dir_nlink,quota,huge_file,64bit,flex_bg -G 256 -E stride=32,stripe-width=224,lazy_journal_init -F /dev/sda 13673619456
Writing CONFIGS/mountdata
+ mkdir -p /export/lard/ost2-1
+ mount -t lustre /dev/sda /export/lard/ost2-1

5.3 Run getfstablabels.sh

[root@lard-oss-2 Lustre]# sh getfstablabels.sh 
device /dev/sda mounted by lustre
Filesystem volume name:   lard-OST0006
device /dev/sdb mounted by lustre
Filesystem volume name:   lard-OST0007
device /dev/sdc mounted by lustre
Filesystem volume name:   lard-OST0008
device /dev/sdd mounted by lustre
Filesystem volume name:   lard-OST0009
device /dev/sde mounted by lustre
Filesystem volume name:   lard-OST000a
device /dev/sdf mounted by lustre
Filesystem volume name:   lard-OST000b

6 Manual tasks after the script runs

• Resume the non-ansiblized instructions at this point