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Provisionning a teuthology target with a given kernel

When a teuthology target (i.e. machine) is provisioned with teuthology-lock for the purpose of testing Ceph, there is no way to choose the kernel. But it can be installed afterwards using the following:

cat > kernel.yaml <<EOF
interactive-on-error: true
roles:
- - mon.a
  - client.0
kernel:
   branch: testing
tasks:
- interactive:
EOF

Assuming the target on which the new kernel is to be installed is vpm083, running

$ teuthology  --owner loic@dachary.org \
  kernel.yaml <(teuthology-lock --list-targets vpm083)
...
2015-03-09 17:47 INFO:teuthology.task.internal:Starting timer...
2015-03-09 17:47 INFO:teuthology.run_tasks:Running task interactive...
Ceph test interactive mode, use ctx to interact with the cluster
>>>

will install an alternate kernel and reboot the machine:

[ubuntu@vpm083 ~]$ uname -a
Linux vpm083 3.19.0-ceph-00029-gaf5b96e #1 SMP Thu Mar 5 01:04:25 GNU/Linux
[ubuntu@vpm083 ~]$ lsb_release -a
LSB Version:	:base-4.0-amd64:base-4.0-noarch:
Distributor ID:	RedHatEnterpriseServer
Description:  release 6.5 (Santiago)
Release:	6.5
Codename:	Santiago

Command line arguments to the kernel may be added to /boot/grub/grub.conf. For instance loop.max_part=16 to allow partition creation on /dev/loop devices:

default=0
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
title rhel-6.5-cloudinit (3.19.0-ceph-00029-gaf5b96e)
        root (hd0,0)
        kernel /boot/vmlinuz-3.19.0 ro root=LABEL=79d3d2d4  loop.max_part=16
        initrd /boot/initramfs-3.19.0.img
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Ceph OSD uuid conversion to OSD id and vice versa

When handling a Ceph OSD, it is convenient to assign it a symbolic name that can be chosen even before it is created. That’s what the uuid argument for ceph osd create is for. Without a uuid argument, a random uuid will be assigned to the OSD and can be used later. Since the ceph osd create uuid is idempotent, it can also be used to lookup the id of a given OSD.

$ osd_uuid=b2e780fc-ec82-4a91-a29d-20cd9159e5f6
# convert the OSD uuid into an OSD id
$ ceph osd create $osd_uuid
0
# convert the OSD id into an OSD uuid
$ ./ceph --format json osd dump | jq '.osds[] | select(.osd==0) | .uuid'
"b2e780fc-ec82-4a91-a29d-20cd9159e5f6"