Rename 'zed.service' to 'zfs-zed.service'

[FransUrbo]

This so that it corresponds to the other systemd files.

$ ll etc/systemd/system/
total 64
-rw-r--r--  1 turbo  staff    41 Jul 24 15:40 50-zfs.preset.in
-rw-r--r--  1 turbo  staff  1124 Sep 23 23:05 Makefile.am
-rw-r--r--  1 turbo  staff   183 Sep 23 23:05 zed.service.in
-rw-r--r--  1 turbo  staff   362 Sep  8 18:19 zfs-import-cache.service.in
-rw-r--r--  1 turbo  staff   355 Sep  8 18:19 zfs-import-scan.service.in
-rw-r--r--  1 turbo  staff   357 Jul 24 15:40 zfs-mount.service.in
-rw-r--r--  1 turbo  staff   302 Sep  8 18:17 zfs-share.service.in
-rw-r--r--  1 turbo  staff   148 Sep 23 23:05 zfs.target.in

Doesn't make sense that the zed start script isn't prefixed with zfs-.

This can cause a problem which we've seen in zfsonlinux/pkg-zfs#172. This isn't the cause of that problem, but it is related.

[FransUrbo]

@behlendorf @nedbass Did you guys miss this into 0.6.5.2? It's quite a no-brainer….

[behlendorf]

I'm on the fence about it. I've no objection to merging it to master (which I should do), consistency is good. But changing this is the release branch would be a significant change in behavior.

[FransUrbo]

This is directly related to #3837. Since there's a /etc/init.d/zfs-zed script, but no corresponding zfs-zed.service service file (it is instead zed.service), we end up with two zeds (if/when it's auto generated)…

But as I've mentioned elsewhere, I'm not sure it's an issue on anything but Debian GNU/Linux (which is, as far as I know, the only one distribution both SYSV scripts and systemd service files at the same time).

Considering that, I have no problems with leaving it out from the point releases if you think that's better. I'm not sure it would be "significant change in behavior" though (keyword "significant")...

[behlendorf]

It's trivial but it's also very user visible. People are used to typing systemctl status zed and I think this would feel like a gratuitous change. However, it dawned on me that systemd does provide the ability to create aliases. Adding an Alias=zed.service to the service file will allow both names to work avoiding any user visible change which should resolve this issue and allow us to add this to the release branch.

It appears to work as expected for me.

$ sudo systemctl status zed
zfs-zed.service - ZFS Event Daemon (zed)
   Loaded: loaded (/usr/lib/systemd/system/zfs-zed.service; enabled)
   Active: active (running) since Fri 2015-10-02 17:32:16 EDT; 2min 22s ago
     Docs: man:zed(8)
 Main PID: 947 (zed)
   CGroup: /system.slice/zfs-zed.service
           └─947 /sbin/zed -F

Oct 02 17:32:16 localhost.localdomain systemd[1]: Started ZFS Event Daemon (z...
Oct 02 17:32:16 localhost.localdomain zed[947]: ZFS Event Daemon 0.6.5-20_g9...)
Oct 02 17:32:16 localhost.localdomain zed[947]: Processing events since eid=0
Hint: Some lines were ellipsized, use -l to show in full.

$ sudo systemctl status zfs-zed
zfs-zed.service - ZFS Event Daemon (zed)
   Loaded: loaded (/usr/lib/systemd/system/zfs-zed.service; enabled)
   Active: active (running) since Fri 2015-10-02 17:32:16 EDT; 2min 26s ago
     Docs: man:zed(8)
 Main PID: 947 (zed)
   CGroup: /system.slice/zfs-zed.service
           └─947 /sbin/zed -F

Oct 02 17:32:16 localhost.localdomain systemd[1]: Started ZFS Event Daemon (z...
Oct 02 17:32:16 localhost.localdomain zed[947]: ZFS Event Daemon 0.6.5-20_g9...)
Oct 02 17:32:16 localhost.localdomain zed[947]: Processing events since eid=0
Hint: Some lines were ellipsized, use -l to show in full.

Merged as:

8f90f73 Rename 'zed.service' to 'zfs-zed.service'