[CFT] ZFS feature flag support for 9-STABLE

[Volodymyr Kostyrko]

02.10.2012 22:48, Martin Matuska wrote:
> ZFS feature flag support is ready to be merged to 9-STABLE.
> The scheduled merge date is short after 9.1-RELEASE.

> Feedback and suggestions are welcome.

+1 from me: works here like a charm.

I have one more question about snapshot removal behavior. I already 
noticed that destroying a snapshot an deduped filesystem can eat a lot 
of ram to complete. Actually my experience was:

1. One of the snapshots was discarded (14G) and system tried to allocate 
more RAM then was available. Machine stalled.
2. After reboot snapshot destruction was automatically restarted. And 
machine stalled again.
3. I booted in single user mode and tried a manual pool import. RAM was 
exhausted again. I assumed that adding swap wouldn't help either.
4. I raised memory on the machine from 4G to 8G. After boot snapshot 
destruction completes topping wired at 6G.

As I understand snapshot destruction goes into one transaction meaning 
that all changed structures should be changed in memory and written to 
disk. Would this code have the same issue?

-- 
Sphinx of black quartz, judge my vow.