Need help to change shmmax

[Dakshayani]

I am working now with the setting of shared memory. As presented to me a few questions that I read so far by looking on the net and could not answer. Can I make SHMMAX greater than the available RAM. Is there a direct relationship between SHMMAX and SHMALL. The way I see it should SHMALL should be larger than the SHMAXX. Is there a connection between the swap partition, and these values. About an answer no matter what question I would be delighted.

[Zhankana_n]

I have a some kind of similar issue. I am new to postgresql. I use openerp and he often goes out errors max_lock_per_transaction. I also saw that kind shared_buffer was very low 32MB. So I wanted to light it up one fifth of the available RAM and 24GB of ram I have on my production server I wanted to put 3-4GB Except that this is the Debian system and shmmax shmall are poorly configured for the coup. I wanted to know how to calculate the optimal way of shmmax. I would like 3GB shared_buffer with ~ 100 and max_connections max_lock_per_transaction 250. I also configure a 1GB effective_cache_size.

[teena_pansare]

There must be a little more than shared_buffers for shmmax. 4 GB would be nice, not worth going over. As for shmall, generally, it is configured. Attention unit shmall is not the same as for shmmax. shmmax is shmall bytes and 4 KB page. It changes quite a bit. Moreover, optimal does not really make sense. This is an administrative boundary, nothing more. The shmmax is (too) low in default to avoid that process can allocate GB shared memory without control. But a system is as efficient as shmmax either 4MB or 20GB.

[Ekpah]

Compiling the kernel is one of the steps that attach to any Linux user in the environment in which it operates. Depending on the size and capabilities possessed by the kernel can be classified. Actually, despite staunch supporters on one model or another, there is a basic tendency to reduce the size of the core providing less functionality, which are displaced to modules loaded at runtime.

[SalVatore]

Your program needs a large shared memory segment, more than allowed by the kernel. You can make the suggestion given, but - echo 0x7fffffff> / proc / sys / kernel / chmmax. I have a second question about bp above, the message is for each restart my computer, how to make the setting permanent please. This is the maximum amount of shared memory that can provide the core.

[Enriquee]

There are so kernel managed resources. I still do not understand what is supposed to be for a shared memory, for which I would set the value. And what is the value if it has not been specified by the system already established.I get maybe a little late, but it can still be useful to someone . In fact the problem is that the shell interprets the redirect instead of passing it to the sub shell of sudo.