Re: Postgres in jails

[Steven Chamberlain <steven@pyro.eu.org>]

Hi,

I don't see any differences in our setup except for my host system being
GNU/kFreeBSD and not upstream FreeBSD.  I also don't have a jexec so I'm
entering the jail by either:

1. jail -m jid=4 command=/bin/bash
2. starting sshd in the jail and then logging into it that way

Maybe the rlimits are in some way different:

> root@jail1001:~# ulimit -a
> socket buffer size       (bytes, -b) unlimited
> core file size          (blocks, -c) 0
> data seg size           (kbytes, -d) 524288
> file size               (blocks, -f) unlimited
> max locked memory       (kbytes, -l) unlimited
> max memory size         (kbytes, -m) unlimited
> open files                      (-n) 1024
> pipe size            (512 bytes, -p) 1
> stack size              (kbytes, -s) 8192
> cpu time               (seconds, -t) unlimited
> max user processes              (-u) 5547
> virtual memory          (kbytes, -v) unlimited

Here are my default shared memory limits:

> root@kfreebsd-i386:~# sysctl -a | grep shm
> kern.ipc.shm_allow_removed: 0
> kern.ipc.shm_use_phys: 0
> kern.ipc.shmall: 4096
> kern.ipc.shmseg: 256
> kern.ipc.shmmni: 192
> kern.ipc.shmmin: 1
> kern.ipc.shmmax: 16777216
> kern.features.sysv_shm: 1
> kern.features.posix_shm: 1


The security.jail.param.allow.sysvipc setting doesn't seem relevant.
Here's a full transcript, but everything seems the same as you've shown me:

> root@jail1001:~# sysctl -a | grep sysv
> kern.features.sysv_msg: 1
> kern.features.sysv_sem: 1
> kern.features.sysv_shm: 1
> security.jail.param.allow.sysvipc: 0
> security.jail.sysvipc_allowed: 0
> root@jail1001:~# pg_createcluster 9.1 main --start
> Creating new cluster (configuration: /etc/postgresql/9.1/main, data: /var/lib/postgresql/9.1/main)...
> could not change directory to "/root"
> FATAL:  could not create shared memory segment: Function not implemented
> DETAIL:  Failed system call was shmget(key=1, size=1900544, 03600).
> child process exited with exit code 1
> initdb: removing contents of data directory "/var/lib/postgresql/9.1/main"
> Error: initdb failed

Then after "jail -m jid=4 allow.sysvipc=1" on the host:

> root@jail1001:~# sysctl -a | grep sysvipc
> security.jail.param.allow.sysvipc: 0
> security.jail.sysvipc_allowed: 1
> root@jail1001:~# pg_createcluster 9.1 main --start
> Creating new cluster (configuration: /etc/postgresql/9.1/main, data: /var/lib/postgresql/9.1/main)...
> could not change directory to "/root"
> Moving configuration file /var/lib/postgresql/9.1/main/postgresql.conf to /etc/postgresql/9.1/main...
> Moving configuration file /var/lib/postgresql/9.1/main/pg_hba.conf to /etc/postgresql/9.1/main...
> Moving configuration file /var/lib/postgresql/9.1/main/pg_ident.conf to /etc/postgresql/9.1/main...
> Configuring postgresql.conf to use port 5432...

Regards,
-- 
Steven Chamberlain
steven@pyro.eu.org