zpool add log to root pool

[Volodymyr Kostyrko]

18.09.2012 14:24, Olivier Smedts wrote:
> 2012/9/17 Charles Sprickman <spork at bway.net>:
>> On Sep 17, 2012, at 8:34 AM, Olivier Smedts wrote:
>>> Is there anyone successfuly using a log device / zil on a root pool
>>> under FreeBSD ?
>>
>> Mine works, but I've never been able to find any official confirmation from the -fs folks as to how "proper" or supported the configuration is.  Not too many other options on 1U boxes though really...
>
> Thanks, I tried and it works for me :
> # zpool set bootfs= tank
> # zpool add tank log gpt/zil
> # zpool set bootfs=tank/freebsd tank
> Rebooted, seems to work... maybe the bootfs property check should be
> disabled in the code ?

There might be some uncertain areas like:

1. Does our bootcode support replaying/reconstructing ZIL before booting?
2. Would the machine boot if log device is missed?
3. How much data can be thrashed when log device fails.

UPS answers most of this questions to me, but my machine is local test 
server, not a production one.

-- 
Sphinx of black quartz judge my vow.