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Former Member
Jun 07, 2016 at 08:29 PM

When ASE uses /dev/shm ?


Hi all,

We installed ASE 15.7 on RHEL 6.7 with Hugepages support on a server with 256GB memory.

ASE started fine with max memory of 120GB and logs indicate using Hugepages.

00:0000:00000:00000:2016/06/06 19:05:32.64 kernel Allocated memory using Huge pages.

00:0000:00000:00000:2016/06/06 19:05:32.65 kernel Internal run-time model set for Linux - Native

00:0000:00000:00000:2016/06/06 19:05:32.65 kernel Adaptive Server is using the threaded kernel mode.

00:0000:00000:00000:2016/06/06 19:05:32.65 kernel Using 40000 file descriptors.

00:0000:00000:00000:2016/06/06 19:05:32.65 kernel Adaptive Server Enterprise/15.7/EBF 25127 SMP SP136 /P/x86_64/Enterprise Linux/ase157sp136x/3955/64-bit/FBO/Mon Oct 19 19:12:00 2015

GLS1_TOK_PRD_ASE.master> conf 'max memory'

Parameter Name Default Memory Used Config Value Run Value Unit Type


max memory 114688 125829120 62914560 62914560 memory pages(2k) dynamic

(1 row affected, return status = 0)

However, /dev/shm is not 120GB used, as seen below.

Filesystem Size Used Avail Use% Mounted on

tmpfs 127G 17G 110G 13% /dev/shm

17GB used is, tempdb devices are under /dev/shm.

Questions are:

1) When ASE uses /dev/shm ?

2) Is it good to put tempdb devices on /dev/shm ?

Thanks for your answers.