[squid-users] squid 3.5.27 does not respect cache_dir-size but uses 100% of partition and fails

[pete dawgg]

THX for your reply!

> Betreff: Re: [squid-users] squid 3.5.27 does not respect cache_dir-size but uses 100% of partition and fails
>
> On 07/11/2018 04:39 AM, pete dawgg wrote:
> 
> > cache_dir aufs /mnt/cache/squid 75000 16 256
> 
> > FATAL: Ipc::Mem::Segment::open failed to shm_open(/squid-cf__metadata.shm): (2) No such file or directory
> 
> If you are using a combination of an SMP-unaware disk cache (AUFS) with
> SMP features such as multiple workers or a shared memory cache, please
> note that this combination is not supported.
I have set workers 8 just recently; but the disk full error had definitely been occuring before.

> The FATAL message above is about a shared memory segment used for
> collapsed forwarding. IIRC, Squid v3 attempted to create those segments
> even if they were not needed, so I cannot tell for sure whether you are
> using an unsupported combination of SMP/non-SMP features.
> 
> I can tell you that you cannot use a combination of collapsed
> forwarding, AUFS cache_dir, and multiple workers. Also, non-SMP
> collapsed forwarding was primarily tested with UFS cache_dirs.
I was not aware of that - i can de-activate the workers 8 setting again.
"Collapsed forwarding" was not set intentionally. This error seems to occur when the disk is
really full and squid is restarted.

> 
> Unfortunately, I cannot answer your question regarding overflowing AUFS
> cache directories. One possibility is that Squid is not cleaning up old
> cache files fast enough. You already set cache_swap_low/cache_swap_high
> aggressively. Does Squid actively remove objects from the full disk
> cache when you start it up _without_ any traffic? If not, it could be a
> Squid bug. Unfortunately, nobody has worked on AUFS code for years
> (AFAIK) so it may be difficult to fix anything that might be broken there.
When there is no traffic squid seems to cleaning up well enough: over night (no traffic)
disk usage went down to 30GB (now it's at 50GB again)

There was another error i just fixed:
> FATAL: Failed to open swap log /mnt/cache/squid/swap.state.new
Not a permissions or diskspace problem, caused by workers 8.
I have deactivated workers 8 and this error went away.

THX for your input!
pete