iSCSI Gateway fails to start due to incorrect pool name or rbd image name configured in "gateway.conf"

This document (000019734) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Enterprise Storage 6

Situation

When the iSCSI Gateway service "rbd-target-api.service" is starting up, it encounters the following type of errors in "/var/log/messages" of the iSCSI Node if the pool name (e.g. "TEST_ISCSI_POOL_1") is incorrect:

rbd-target-api[xxxx]: File "/usr/lib/python3.6/site-packages/ceph_iscsi_config/lun.py", line 1323, in define_luns
rbd-target-api[xxxx]: with cluster.open_ioctx(pool) as ioctx:
rbd-target-api[xxxx]: File "rados.pyx", line 516, in rados.requires.wrapper.validate_func
rbd-target-api[xxxx]: File "rados.pyx", line 1203, in rados.Rados.open_ioctx
rbd-target-api[xxxx]: rados.ObjectNotFound: [errno 2] error opening pool 'b'TEST_ISCSI_POOL_1''
......
rbd-target-api[xxxx]: File "/usr/lib/python3.6/site-packages/ceph_iscsi_config/target.py", line 404, in load_config
rbd-target-api[xxxx]: ip_address = list(tpg.network_portals)[0].ip_address
rbd-target-api[xxxx]: IndexError: list index out of range

If the RBD (Rados Block Device) image name (e.g. "ISSCI_TEST_IMAGE") is incorrect, the following type of errors are printed:

rbd-target-api[xxxx]: File "/usr/lib/python3.6/site-packages/ceph_iscsi_config/lun.py", line 1330, in define_luns
rbd-target-api[xxxx]: with rbd.Image(ioctx, image_name) as rbd_image:
rbd-target-api[xxxx]: File "rbd.pyx", line 2947, in rbd.Image.__init__
rbd-target-api[xxxx]: rbd.ImageNotFound: [errno 2] error opening image b'ISSCI_TEST_IMAGE' at snapshot None
......
rbd-target-api[xxxx]: File "/usr/lib/python3.6/site-packages/ceph_iscsi_config/target.py", line 404, in load_config
rbd-target-api[xxxx]: ip_address = list(tpg.network_portals)[0].ip_address
rbd-target-api[xxxx]: IndexError: list index out of range

Resolution

The configuration in the "gateway.conf" file for the iSCSI Gateway contains an incorrect pool name or RBD image name and needs to be updated with the correct information.

1. Find out the correct pool name and RBD image name used in the iSCSI configuration:

# rados lspools
test_iscsi_pool_1

# rbd -p test_iscsi_pool_1 ls
issci_test_image

In this example, the correct pool name is "test_iscsi_pool_1" and the correct RBD image name is "issci_test_image". The error is caused by upper case being used for the pool name and image names inside the "gateway.conf" file.

2. Get the "gateway.conf" file from the iSCSI pool:

# rados -p iscsi-images get gateway.conf /tmp/gateway.conf

In this example, the pool name used by the iSCSI Gateway is "iscsi-images". Note however that the pool name can be different in other iSCSI deployments. The pool name is configured in "/etc/ceph/iscsi-gateway.cfg" located on the designated iSCSI node(s).

3. Modify the "gateway.conf" file to ensure the correct pool name (e.g. "test_iscsi_pool_1") and image name (e.g. "issci_test_image") are used in the iSCSI configuration:

...
"disks": {
"test_iscsi_pool_1/issci_test_image": {
"allocating_host": "ses6-node2.example.com",
"backstore": "rbd",
"backstore_object_name": "test_iscsi_pool_1.issci_test_image",
"controls": {},
"created": "2020/09/30 06:14:43",
"image": "issci_test_image",
"owner": "ses6-node2.example.com",
"pool": "test_iscsi_pool_1",
"pool_id": 10,
"updated": "2020/09/30 06:14:44",
"wwn": "16d74503-39d6-433a-81c4-e969119937d0"
}
...
"targets": {
...
"iqn.2001-07.com.ceph:1601446434222": {
...
"disks": {
"test_iscsi_pool_1/issci_test_image": {
"lun_id": 0
}
},
...

4. Put the modified file "gateway.conf" back to the iSCSI pool. For example if the file is saved in "/tmp/gateway.conf":

# rados -p iscsi-images put gateway.conf /tmp/gateway.conf

5. Start the iSCSI Gateway service on the iSCSI Node(s):

# systemctl reset-failed rbd-target-api.service
# targetcli clearconfig confirm=True
# systemctl start rbd-target-api.service

6. Check the status of the iSCSI Gateway service to confirm it is running:

# systemctl status rbd-target-api.service

Cause

The "gateway.conf" file for the iSCSI Gateway contains an incorrect pool name or RBD image name.

Status

Reported to Engineering

Disclaimer

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