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ISCSI disks

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ISCSI disks are not starting automatically. Is that behavior is by design ?

If you mean they do not start automatically if you shutdown the entire cluster and restart it, then yes.

PetaSAN is not meant to be restarted all the time, a restart is like recovering fro disaster case. For iSCSI disks to function the Ceph and Consul servers need to be running,  Ceph servers needs to sync to make sure all data  is up to date. The admin should start the disks only when this is met, it will help maybe if e add a "restart all" operation.

Yes I mean after restarting CEPH cluster, ISCSI disk are not starting.  I have the following scenario four nodes with ESX i 6. Each one is holding one Petasan node. Petasan cluster is servicing ISCSI disks on which disks I have VMs which supposedly will start after shared volumes are presented to ESX i hosts. I have modified /etc/rc.local.d/local.sh in ESX i hosts in folowing manaer:

#!/bin/sh

# local configuration options

# Note: modify at your own risk! If you do/use anything in this
# script that is not part of a stable API (relying on files to be in
# specific places, specific tools, specific output, etc) there is a
# possibility you will end up with a broken system after patching or
# upgrading. Changes are not supported unless under direction of
# VMware support.

# Start the VM Server that provides the iSCSI LUN

vim-cmd vmsvc/getallvms | grep Petasan0.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

sleep 90

vim-cmd vmsvc/getallvms | grep Petasan1.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

sleep 90

vim-cmd vmsvc/getallvms | grep Petasan2.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

sleep 90

vim-cmd vmsvc/getallvms | grep Petasan3.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

sleep 90

 

vim-cmd vmsvc/getallvms | grep VCSA-1.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

sleep 90

vim-cmd vmsvc/getallvms | grep DOM-1.vmx | cut -d ' ' -f 1 | vim-cmd vmsvc/power.on

# Other VMs

esxcfg-swiscsi -e

esxcfg-swiscsi -s

sleep 10

exixcli storage core adapter rescan --all

exit 0

----------------------------

This script works well with openATTIC cluster but not with Petasan because ISCSI disks are not starting automatically. Is it possible to have script inside Petasan which will do all checks on the ceph cluster and then start ISCSI disks ?

Yes it could be done. but i would consider first why do you need to manually restart the cluster on a regular basis in the first place since as i mentioned Ceph will take time to stabilize if the entire cluster is restarted. Also what is the impact of having to manually restart the disks in such cases ?

In a traditional SAN it is easy for a node to start an iSCSI service when it boots. A PetaSAN node starting cannot assume that all other cluster nodes are also starting with it at the same time. It is possible to do, however it will be more involved than the traditional case and i am not sure it will be that beneficial. Maybe a manual restart all will be acceptable.

Never mind. I am using CEPH clusters on DR sites for various clients. Most of this DR sites have no UPS backup power, or some of them have backup for 10-15 min. After power outage DR sites will start automatically and continue replication, that is the main reason for starting ISCSI disks automatically. Presently I am using open ATTIC and Deepsea deployment, and it works well. The only difference is that Petasan is much more easy to deploy and maintain.

Would a script to start an iSCSI disk help you ? You can use sleep as you did in the script you posted to start after some time.

Yes defensively will help. Unfortunately I am not familiar neither with CONSUL nor with LIO target. In fact on all my deployments of CEPH I am using SCST project for ISCSI targets  and RBDMAP. If you could give me a clue as to how start from console ISCSI disks I can then figure out how to write remote script from ESXi  hosts. I will really appreciated this because Petasan is a great idea.

I will post the script here by Monday if not tomorrow

Thanks really appreciated !

Here is the script, it will start all non started disks.

https://drive.google.com/file/d/1IKFZNLDVC88nlnyOg-l6RO8QNQZGUwlr/view?usp=sharing

best place it in

/opt/petasan/scripts/util/start_all_disks.py

since we will add it in next versions

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