[Solved] /dev/disk/by-id: WWN sometimes is missing - implications?

[Meow]

Problem:
For some drive(s) the system sometimes does not create the appropriate wwn-0x... links.
Here, in case of a HP S700 SSD, It sometimes only creates the ata-... links.

This causes timeouts in the boot process when the system looks for the drives which were announced to it using the wwn-... link instead of ata-... or just sdX.

(When the boot process continues after that timeout, ZFS on linux itself recognizes the ZFS filesystems itself automagically, so bad data in fstab or whatever usually does not matter that much)

Questions:
Often in documents/instructions it is recommended to use the WWN identification method, as it is most convenient and safe, because every device's WWN is written on it.
But now I feel no longer sure about this.

1. Am I doing something grossly wrong which made the wwn-... identification links not appear?
2. Or, is this normal behaviour which makes more prudent to use the ata-... link instead of the wwn-...?

[Aki]

Hello,

Often in documents/instructions it is recommended to use the WWN identification method, as it is most convenient and safe, because every device's WWN is written on it. But now I feel no longer sure about this.

Can you please provide a reference to an example of these documents/instructions?

[Meow]

Can you please provide a reference to an example of these documents/instructions?

Well, I read again the Root on ZFS manual, I misinterpreted that.
It strongly recommended there to use the links in /dev/disk/by-id/ instead of " sda", "sdb" etc when specifying particular drives, as the latter might change.

If the wwn thing would work reliably, this would be nice. But I read there is a lot of udev stuff etc to get right for that.
So I for now have modified my script to use the ata-... instead of the wwn- references.
Not a big deal.

[Aki]

Hello,

Can you please provide a reference to an example of these documents/instructions?

Well, I read again the Root on ZFS manual, I misinterpreted that. It strongly recommended there to use the links in /dev/disk/by-id/ instead of " sda", "sdb" etc when specifying particular drives, as the latter might change.

If the wwn thing would work reliably, this would be nice. But I read there is a lot of udev stuff etc to get right for that.
So I for now have modified my script to use the ata-... instead of the wwn- references.
Not a big deal.

I'm glad you sorted it out. :)

Please, mark the discussion as "solved" manually adding the text tag "[Solved]" at the beginning of the subject of the first message (after other tags, if any).

Thanks.

Happy Debian ! :)