Hi there, I want to improve open-iscsi packaging in Debian and I've stumbled upon the question of what to do on package upgrades. Currently, Debian's package doesn't do anything on upgrades, i.e. the old iscsid is left running. (The current documentation in Debian is misleading when it comes to updates btw.)
I have a couple of questions about that: 1. How stable is the socket protocol between iscsiadm and iscsid? Are there any guarantuees there? Or could it happen that you upgrade and then the new iscsiadm can't properly talk to the old iscsid (which is needed at e.g. shutdown to log out)? But even if the protocol is guaranteed to be stable: is that a good idea? In principle, there could be security upgrades in the future, where you'd want to restart iscsid... which leads to: 2. What I'd rather like to do is just restart iscsid (but keep the currently active iSCSI sessions). From my short tests it seems to work, and I observe this: - Stopping iscsid seems to be completely harmless, the TCP connections of the current session remain open and storage is still acessible. Obviously, if you need to react to external events and e.g. change portals, that won't happen in this case (without iscsid running), but for a short period of time, this should be perfectly fine. - Starting iscsid again, it will close the current TCP connections for the sessions, reconnect to the portal and then use that. It also says 'connection1:0 is operational after recovery (1 attempts)', although that typically takes a couple of seconds after it started. I didn't notice any trouble with the storage, filesystems reamined mounted, no kernel messages (even active I/O would continue, blocking only for a very short amount of time). - Also, with root on iSCSI, you typically have the configuration: initramfs uses iscsistart to log in initially, then when the system comes up properly iscsid is started for the first time. So there you already have the case that iscsid is regularily started with already active iSCSI sessions. On the other hand, I don't have any weird corner-case configurations here (my test system is in fact a VM that connects to a software target), so I can't test any really weird setups. What I want to know there is: - Is it safe to restart iscsid? (As long as it can log in to the target again it should be, right?) Are there any side effects? - If it generally is: can you think of any idea why it wouldn't be a good idea to restart iscsid after upgrading the package? Note: package upgrades of open-iscsi should be a rare occurrence: during the lifetime of a Debian stable release there should only be some if there are really serious bugs (security or otherwise), and then every time an upgrade is done to a new Debian version. Thanks in advance for your responses. Christian -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at http://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
