Changing data seg size kernal parameter

[Dennis Handly]

>I am bit confuse about the "Oracle uses SGA which is taken from shmmax". Appropriate if you can give further idea on that.

Basically Oracle's SGA is taken from shared memory so multiple processes can use it. This is limited by the kernel parm shmmax, not maxdsiz.

[Shehan]

Hi Dennis

You mean we don't need to change this parameter in order to resolve this issue. is it?

Regards
Nirukshitha

[Dennis Handly]

>You mean we don't need to change this parameter in order to resolve this issue. is it?

I don't think I saw your current values for maxdsiz and maxdsiz_64bit??
I would suggest you increase maxdsiz to 1 Gb
and maxdsiz_64bit to 4 Gb, if they aren't already at those values.

[Shehan]

Hi Dennis

Please see below for the current valves.

maxdsiz 1073741824
maxdsiz_64bit 2147483648

So, please let me know more suitable values.


Regards
Nirukshitha

[Venkatesh BL]

Your current maxdsiz_64bit is '2 GB'. The maximum allowed value is '4396972765184' bytes (4GB)

[Shehan]

Hi Dennis

You have proposed the maximum level. But I am afraid to increase it to maximum because it might be impact to other applications as well. So I am supposing to increase it to 3GB level(mid range). Is it possible to increase to value between 2-4 GB?

Regards
Nirukshitha

[Dennis Handly]

>please let me know more suitable values.

Suitable depends on your applications. You only need to increase it if your application needs that much data space.

>Venkatesh: The maximum allowed value is (4GB)

For maxdsiz. The maximum for maxdsiz_64bit is zillions (0x3ffbffff000) of bytes, not the piddly 4 Gb.

>So I am supposing to increase it to 3GB level (mid range). Is it possible to increase to value between 2-4 GB?

Sure you can use values between 2 and 4 Gb.

[Shehan]

Hi Dennis

If we set to 3Gb, is there a byte pattern like 4GB(0x3ffbffff000). How do we calculate this 3GB into byte pattern?

Regards
Nirukshitha

[Venkatesh BL]

3*1024*1024*1024 (3GB) =
3221225472 (decimal) 0xc0000000 (hexa)

[Shehan]

Hi Dennis

If we take this calculation to 4GB, hax valve is incorrect. Please advice.

Also let me know whether we need to use hax valve or decimal valve for this parameter?

Regards
Nirukshitha