Date: Tue, 16 Oct 2012 19:58:36 -0400 From: Fbsd8 <fbsd8@a1poweruser.com> To: freebsd-questions@freebsd.org, David Wolfskill <david@catwhisker.org> Subject: Re: IPCS resource access within a down-level jail? Message-ID: <507DF4AC.3000003@a1poweruser.com> In-Reply-To: <20121016205149.GA1817@albert.catwhisker.org> References: <20121016205149.GA1817@albert.catwhisker.org>
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David Wolfskill wrote: > [Please include me in responses; I've set Reply-To as a hint. Thanks!] > > A colleague had been running a program that makes use of IPCS message > queues in a 7.x/i386 environment. > > He was moved to a 32-bit 7.x-based jail instantiated on an 8.x/amd64 > host. > > Within that jail, "ipcs -a" now fails to come anywhere near close to > reporting what it does outside the jail. > > I then performed an experiment: I created a 7.x/i386 jail on my > 9.x/i386 laptop. I verified that "ipcs -a" (outside the jail) shows > Stuff: > > d134(9.1-P)[1] ipcs -a > Message Queues: > T ID KEY MODE OWNER GROUP CREATOR CGROUP CBYTES QNUM QBYTES LSPID LRPID STIME RTIME CTIME > > Shared Memory: > T ID KEY MODE OWNER GROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIME DTIME CTIME > m 393216 0 --rw------- david david david david 2 393216 3671 3147 8:23:37 no-entry 8:23:37 > m 851969 0 --rw------- david david david david 2 262080 3861 3147 9:24:09 no-entry 9:24:09 > m 458754 0 --rw------- david david david david 2 384000 3861 3147 9:24:09 no-entry 9:24:09 > > Semaphores: > T ID KEY MODE OWNER GROUP CREATOR CGROUP NSEMS OTIME CTIME > > d134(9.1-P)[2] > > > Inside the jail, using the 7.x version of ipcs, I get: > > %ipcs -a > ipcs: sysctlbyname: kern.ipc.msqids: Cannot allocate memory > % > > I then recompiled the 9.x versions of ipcs & ipcrm and linked them > statically; running that verion of ipcs, I see: > > %~/bin/!! > ~/bin/ipcs -a > Message Queues: > T ID KEY MODE OWNER GROUP CREATOR CGROUP CBYTES QNUM QBYTES LSPID LRPID STIME RTIME CTIME > > Shared Memory: > T ID KEY MODE OWNER GROUP CREATOR CGROUP NATTCH SEGSZ CPID LPID ATIME DTIME CTIME > m 393216 0 --rw------- david david david david 2 393216 3671 3147 15:23:37 no-entry 15:23:37 > m 655362 0 --rw------- david david david david 2 262080 3861 3147 18:39:30 no-entry 18:39:30 > > Semaphores: > T ID KEY MODE OWNER GROUP CREATOR CGROUP NSEMS OTIME CTIME > > % > > Is this (inability to access IPCS resources properly within a > "down-level" jail) expected behavior? > > Is there a sane(?) way to provide IPCS resources inside a down-level > jail? > > Thanks! > > Peace, > david Your problem is in the way you are trying to use jails. The jail has to be at the same major release level as the host. Host being 9.2 with a jail at 9.0 may work. But 9.x or 8.x host with 7.x jail for sure will not work.
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