zpool failmode=wait

[Johnny Fartpants]

Hi All,

I've only recently noticed that failmode on freenas-boot is set to =wait however the data pool itself is set to =continue. It got me thinking that in an environment where you mirror the boot drives shouldn't this be set to =continue so that in the event of a boot drive failing the system will continue to function without waiting for user intervention?

I haven't actually had a mirrored boot drive fail so not sure what normal behaviour is.

I'd be interested to hear your thoughts as to if this is a potential issue or not?

Thanks

 

[toadman]

=wait is the default I believe.

But note, if I recall correctly, failmode covers function in a catastrophic failure. If you have a failed drive in a mirror and the other drive is good, that is not catastrophic. A catastrophic failure would be a 2 drive stripe where one drive fails. At that point the pool is suspended and nothing works if failmode=wait. The reason being is the sysadmin is given an opportunity to "fix" the issue. =continue gets you some commands (maybe) vs. wait which gets you none.

So I can see why the boot pool would be "wait" as you can't continue booting anyway. So you have to fix it one way or another. Either fix the boot pool or reinstall I suppose. I suppose the thinking on setting a data pool to =continue is that is may give the sysadmin some additional info about the pool to use in aiding a fix on an otherwise running system.