On 4/10/03 8:10 pm, "Tom Lane" <[EMAIL PROTECTED]> wrote: > I said: >> Hm. The parallel regression tests require at least 20. I deliberately >> allowed initdb to select values as small as 10 on the theory that >> installing and not being able to run the parallel regression tests is >> better than not installing at all. > > Actually, after trying to reproduce the problem on my own OS X machine, > I realize that it's a little more subtle than I thought. The Darwin > port does not use SysV semaphores at all (it uses Posix semaphores) and > so the resource restriction you're hitting must actually be the > max-shared-memory limit, rather than number-of-semaphores as I first > assumed. max_connections does have an impact on shared memory size, > though not as large as shared_buffers has. > > Therefore, the real problem is that initdb initially probes for a > workable number of shared_buffers while using max_connections=5, and > then it selects max_connections while holding shared_buffers constant. > I was thinking that a small max_connections would prevent us from > mistakenly choosing tiny shared_buffers when the system's real > restriction is on number of semaphores. But what we seem to have here > is that the selected number of buffers was just a little under the > system's max-shared-memory limit, so that max_connections could be > raised to 10 but not to 20. > > (BTW, on my OS X machine, with out-of-the-box configuration, initdb > selects shared_buffers 400 and max_connections 20. I'm guessing that > you had either a nondefault shared memory limit, or some other process > using shared memory.)
These are my current settings sysctl -w kern.sysv.shmmax=4194304 sysctl -w kern.sysv.shmmin=1 sysctl -w kern.sysv.shmmni=32 sysctl -w kern.sysv.shmseg=8 sysctl -w kern.sysv.shmall=1024 This is a laptop so I have quite a few other apps running, including my current PostgreSQL installation (7.2.3), the settings of which are #max_connections = 32 shared_buffers = 100 Let me know if you need any more info? Thanks Adam -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org