Thread: Shared memory error using initdb on Solaris 8
Hello,
I'm trying to install PostgreSQL 7.4.2 on a brand new SunFire 120 with
2GB of RAM but when I run initdb -D /usr/local/pgsql/data I get the
following error:
creating directory /usr/local/pgsql/data... ok
creating directory /usr/local/pgsql/data/base... ok
creating directory /usr/local/pgsql/data/global... ok
creating directory /usr/local/pgsql/data/pg_xlog... ok
creating directory /usr/local/pgsql/data/pg_clog... ok
selecting default max_connections... 10
selecting default shared_buffers... 50
creating configuration files... ok
creating template1 database in /usr/local/pgsql/data/base/1... FATAL: could
not create shared memory segment: Invalid argument
DETAIL: Failed system call was shmget(key=1, size=1081344, 03600).
HINT: This error usually means that PostgreSQL's request for a shared
memory segment exceeded your kernel's SHMMAX parameter. You can either
reduce the request size or reconfigure the kernel with larger SHMMAX. To
reduce the request size (currently 1081344 bytes), reduce PostgreSQL's
shared_buffers parameter (currently 50) and/or its max_connections parameter
(currently 10).
If the request size is already small, it's possible that it is less
than your kernel's SHMMIN parameter, in which case raising the request size
or reconfiguring SHMMIN is called for.
The PostgreSQL documentation contains more information about shared
memory configuration.
initdb: failed
initdb: removing data directory "/usr/local/pgsql/data"
When I run ulimit -a I get
time(seconds) unlimited
file(blocks) unlimited
data(kbytes) unlimited
stack(kbytes) 8192
coredump(blocks) 0
nofiles(descriptors) 256
vmemory(kbytes) unlimited
There does not seem to be an option in initdb to reduce the shared buffers
size. Plus, with 2GB of RAM I don't know that I'd want to go below the
"lowest common denominator" that Postgres defaults to.
Kevin
>
> Hello,
> I'm trying to install PostgreSQL 7.4.2 on a brand new SunFire 120 with
> 2GB of RAM but when I run initdb -D /usr/local/pgsql/data I get the
> following error:
>
[snip]
> creating template1 database in /usr/local/pgsql/data/base/1... FATAL: could
> not create shared memory segment: Invalid argument
> DETAIL: Failed system call was shmget(key=1, size=1081344, 03600).
> HINT: This error usually means that PostgreSQL's request for a shared
> memory segment exceeded your kernel's SHMMAX parameter.
[snip]
>
> When I run ulimit -a I get
>
[snip]
You're looking at the wrong thing. You need to do:
sysdef |egrep -i 'shm|sem'
>
> There does not seem to be an option in initdb to reduce the shared buffers
> size.
It tries to reduce things as far as it "sanely" can to fit within
what's available. You can hand-tweak initdb to over-ride its
limits, but you'd end-up with a sub-optimal installation.
> Plus, with 2GB of RAM I don't know that I'd want to go below the
> "lowest common denominator" that Postgres defaults to.
Nope. You need to adjust certain values by placing settings in
/etc/system and rebooting. I use:
/etc/system
set shmsys:shminfo_shmmax=0x2000000 (33554432 decimal)
set shmsys:shminfo_shmmin=1
set shmsys:shminfo_shmmni=256
set shmsys:shminfo_shmseg=256
set semsys:seminfo_semmap=256
set semsys:seminfo_semmni=512
set semsys:seminfo_semmns=512
set semsys:seminfo_semmsl=32
I arrived at the above values from Google'ing.
Jim
There we go. For reference, what page did you get that info and what did you search for to get it? Kevin ----- Original Message ----- From: "Jim Seymour" <jseymour@LinxNet.com> To: <pgsql-admin@postgresql.org> Sent: Friday, May 21, 2004 10:57 AM Subject: Re: [ADMIN] Shared memory error using initdb on Solaris 8 > > > > Hello, > > I'm trying to install PostgreSQL 7.4.2 on a brand new SunFire 120 with > > 2GB of RAM but when I run initdb -D /usr/local/pgsql/data I get the > > following error: > > > [snip] > > creating template1 database in /usr/local/pgsql/data/base/1... FATAL: could > > not create shared memory segment: Invalid argument > > DETAIL: Failed system call was shmget(key=1, size=1081344, 03600). > > HINT: This error usually means that PostgreSQL's request for a shared > > memory segment exceeded your kernel's SHMMAX parameter. > [snip] > > > > When I run ulimit -a I get > > > [snip] > > You're looking at the wrong thing. You need to do: > > sysdef |egrep -i 'shm|sem' > > > > > There does not seem to be an option in initdb to reduce the shared buffers > > size. > > It tries to reduce things as far as it "sanely" can to fit within > what's available. You can hand-tweak initdb to over-ride its > limits, but you'd end-up with a sub-optimal installation. > > > Plus, with 2GB of RAM I don't know that I'd want to go below the > > "lowest common denominator" that Postgres defaults to. > > Nope. You need to adjust certain values by placing settings in > /etc/system and rebooting. I use: > > /etc/system > set shmsys:shminfo_shmmax=0x2000000 (33554432 decimal) > set shmsys:shminfo_shmmin=1 > set shmsys:shminfo_shmmni=256 > set shmsys:shminfo_shmseg=256 > > set semsys:seminfo_semmap=256 > set semsys:seminfo_semmni=512 > set semsys:seminfo_semmns=512 > set semsys:seminfo_semmsl=32 > > I arrived at the above values from Google'ing. > > Jim > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faqs/FAQ.html
> > There we go. For reference, what page did you get that info and what did > you search for to get it? Like I said: I derived it all from Google'ing on various search terms, IIRC. Probably things like "postgresql+Solaris+shmmax" and the like. I didn't save any URL references. Jim
Searching Google brought up this page. http://www.postgresql.org/docs/current/interactive/kernel-resources.html ----- Original Message ----- From: "Jim Seymour" <jseymour@LinxNet.com> To: <pgsql-admin@postgresql.org> Sent: Friday, May 21, 2004 1:14 PM Subject: Re: [ADMIN] Shared memory error using initdb on Solaris 8 > > > > There we go. For reference, what page did you get that info and what did > > you search for to get it? > > Like I said: I derived it all from Google'ing on various search > terms, IIRC. Probably things like "postgresql+Solaris+shmmax" and > the like. I didn't save any URL references. > > Jim > > ---------------------------(end of broadcast)--------------------------- > TIP 8: explain analyze is your friend
Apologies in advance for the somewhat off-topic post. This is quite a sophisticated group so it strikes me as the right group of people to ask. I'm trying to find someone experienced in scaling open-source, database-backed web applications. Particularly, I have an application based on Linux-Apache-PHP-Postgres, that my customer would like to scale to support 500 simultaneous users (by which they do mean 500 simultaneous submits, since the app gets used that way). I'd like to find someone who has done this, minimally with Apache and other middleware + db, ideally with PHP and more ideally with PHP-postgres. I need it to be someone who has actually done it, as opposed to someone with a theoretical knowledge of how it should be done. If you are such a person, or you know of one, can you please email me offline at slane@moyegroup.com? -- sgl