Borja Marcos
Contributor
- Joined
- Nov 24, 2014
- Messages
- 125
Hi,
I haven't created a proper bug report because I don't have decent data yet. So take this as a "ring a bell" thing.
Server with 16 GB of memory running CORE (13.0-U6.1). It has several jails running somewhat heavy stuff (One with Opensearch, another one with Plex, another one with LibreNMS which means nginx+php+mysql).
It works like a charm, so no complaints.
However, when compiling a heavy port (MongoDB) inside a jail Inactive memory skyrocketed. Up to 9 GB! Which of course applied an enormous pressure on the ZFS ARC.
In the past, facing this situation, I had rebooted the machine and of course it had gone back to normal. This time I have tried to "solve" it by stopping stuff. So I stopped the jails. No success.
The surprise has come when, after restarting the jails (inactive memory was still insanely high!) I have gone to the mongodb port directory and I have done a "make clean".
POOF! Inactive memory back to normal levels.
Remember that I hadn't stopped the server, just the jails.
So, hypothesis:
- Files created from inside a jail get somewhat "sticky" as inactive memory (cache?).
- For some reason that inactive memory is nore reclaimed even if stopping the jails.
- Restarting the jail and doing a "make clean" somewhat "finds" memory associated to those files and, when deleting them, actually purges that inactive memory.
The huge drop in inactive memory is the "make clean". The new inactive level is so low maybe because, before the make clean, I was playing with sysctl vm.v_inactive_target.
Now, if this rings a bell I may arrange for some more tests. I have commented on a FreeBSD bug, 256507 which might be somewhat related.
I haven't created a proper bug report because I don't have decent data yet. So take this as a "ring a bell" thing.
Server with 16 GB of memory running CORE (13.0-U6.1). It has several jails running somewhat heavy stuff (One with Opensearch, another one with Plex, another one with LibreNMS which means nginx+php+mysql).
It works like a charm, so no complaints.
However, when compiling a heavy port (MongoDB) inside a jail Inactive memory skyrocketed. Up to 9 GB! Which of course applied an enormous pressure on the ZFS ARC.
In the past, facing this situation, I had rebooted the machine and of course it had gone back to normal. This time I have tried to "solve" it by stopping stuff. So I stopped the jails. No success.
The surprise has come when, after restarting the jails (inactive memory was still insanely high!) I have gone to the mongodb port directory and I have done a "make clean".
POOF! Inactive memory back to normal levels.
Remember that I hadn't stopped the server, just the jails.
So, hypothesis:
- Files created from inside a jail get somewhat "sticky" as inactive memory (cache?).
- For some reason that inactive memory is nore reclaimed even if stopping the jails.
- Restarting the jail and doing a "make clean" somewhat "finds" memory associated to those files and, when deleting them, actually purges that inactive memory.
The huge drop in inactive memory is the "make clean". The new inactive level is so low maybe because, before the make clean, I was playing with sysctl vm.v_inactive_target.
Now, if this rings a bell I may arrange for some more tests. I have commented on a FreeBSD bug, 256507 which might be somewhat related.
