Configuration options and parameters

There are many options and parameters you can use when running the storpool_cg tool with the conf command. When needed, you can save the parameters in a file.

Configuration options

When running the storpool_cg conf command you can use the options listed below.

-C / --configfile: Configuration file for the tool.
-D / --dump-configfile: Write the config for the tool in the specified file.
-E / --expand: Allow the migration to increase the cpus count for StorPool. Off by default.
-i / --interactive: Migration interactive mode. Use together with -M. Off by default.
-L / --preserve-limits: Preserve existing memory limits when migrating. Off by default.
-M / --migrate: Apply the configuration live. Off by default.
-N / --noop: No operation, only print the configuration; see Understanding results for details. Off by default.
-P / --preserve-cpus: Preserve cpus and cpu bindings when migrating. Off by default.
-v / --verbose: Verbosity level. Default is 0.

Saving a configuration as a file

You can use the -D option to save the configuration detected by storpool_cg as a file. For example, by running storpool_cg conf --noop converged=1 --dump-configfile my-cgconf.cfg the configuration would be saved in the my-cgconf.cfg file. Note that my-cgconf.cfg is a valid configuration file for storpool_cg. As shown below, you can create the file and check its content:

$ storpool_cg conf --noop converged=1 --dump-configfile my-cgconf.cfg
##########START SUMMARY##########
slice: machine limit: 356G
slice: storpool limit: 16134M
  subslice: storpool/common limit: 12806M
  subslice: storpool/alloc limit: 3328M
slice: system limit: 2836M
slice: user limit: 2G
#################################
cpus for StorPool: [3, 5, 7, 23, 25, 27]
socket:0
  core: 0 cpu: 0,20
  core: 1 cpu: 2,22
  core: 2 cpu: 4,24
  core: 3 cpu: 6,26
  core: 4 cpu: 8,28
  core: 8 cpu:10,30
  core: 9 cpu:12,32
  core:10 cpu:14,34
  core:11 cpu:16,36
  core:12 cpu:18,38
socket:1
  core: 0 cpu: 1,21
  core: 1 cpu: 3,23 <--- 3 - rdma; 23 - server
  core: 2 cpu: 5,25 <--- 5 - server_1; 25 - mgmt,beacon
  core: 3 cpu: 7,27 <--- 7 - iscsi; 27 - block
  core: 4 cpu: 9,29
  core: 8 cpu:11,31
  core: 9 cpu:13,33
  core:10 cpu:15,35
  core:11 cpu:17,37
  core:12 cpu:19,39
#################################
SP_CACHE_SIZE=1024
SP_CACHE_SIZE_1=4096
###########END SUMMARY###########

$ cat my-cgconf.cfg
##########START CONFIG##########
[cgtool]
CONVERGED=1
BLOCK=1
ISCSI=1
MGMT=1
BRIDGE=0
SERVERS=2

SET_CACHE_SIZE=1
SP_COMMON_LIMIT=12806M
SP_ALLOC_LIMIT=3328M
SYSTEM_LIMIT=2836M
KERNEL_MEM=1G
USER_LIMIT=2G
MACHINE_LIMIT=356G

IFACE=p4p1
IFACE_ACC=1

CORES=3

CONFDIR=/etc/cgconfig.d
CACHEDIR=/etc/storpool.conf.d

###########END CONFIG###########

Using the configuration file

Having a configuration file can be useful when you need to tweak the parameters, and also in cases like the one described in Configuring multiple similar machines.

Assume you have a configuration file with a name like my-cgconf.cfg. You can simply run storpool_cg by telling it about the file:

storpool_cg conf --noop --configfile my-cgconf.cfg

You may override (or specify) parameters in the config file from the command line by listing parameter=value pairs. Here is an example:

storpool_cg conf --noop --configfile my.cfg cores=4 converged=1 iface=sp0

This command would set 4 cores and the sp0 interface to be used, and will make a converged setup no matter what are the values (if any at all) of the CORES, CONVERGED, and IFACE parameters in the configuration file (explained below).

When upgrading a machine (not creating the control groups configuration for the first time) you may utilize the following options:

-P (--preserve-cpus) will read the cpuset configuration for the storpool.slice (only) and will keep it unchanged. Some cpuset subslices of storpool.slice might be deleted during the migration (because they are not needed in the new configuration), so their cpuset won’t be preserved.
-L (--preserve-limits) will read the memory limits of the storpool (and its subslices), system, user, and machine slices and will keep them unchanged. This option will also try to preserve the memory left for the kernel.

Configuration parameters

As shown in the example above, the configuration file for the tool consists of a single section named cgtool. It can contain the parameters listed below.

Note

As described in the previous section, these parameters can also be provided on the command line as parameter=value pairs.

BLOCK, ISCSI, MGMT, BRIDGE: Boolean. Specify whether the corresponding Storpool service will be used on the machine. If not specified, will detect which services are installed and set them to True. Consider that the services should be enabled after the configuration of cgroups is completed; for details, see 10. Managing services with storpool_ctl.
CACHEDIR: Path to the directory where server cache configuration file (cache-size.conf) for StorPool servers will be written; default is /etc/storpool.conf.d.
CONFDIR: Path to the directory where control group configuration files will be written; default is /etc/cgoconfig.d.
CONVERGED: Boolean, default is False. Specify whether the machine is hyperconverged or not; cannot be detected.
CORES: The number of cores dedicated to StorPool services. Note that if the machine supports hyperthreading then 4 cores = 8 CPUs, and if not then 4 cores = 4 CPUs. For hyperthreaded machines you may specify for example 3.5 cores, which are 3 cores (6 CPUs) plus one thread (CPU) from a different core.
IFACE: Network interface for StorPool. Should be a machine raw device, for example enp1s0f0. If not specified the value from the storpool.conf will be taken.
IFACE_ACC: Boolean. Specify whether the network interface should use hardware acceleration. If not specified it will be detected. Use this with care, only for overwriting the detection.
KERNEL_MEM: Non-negative integer, use one of the M or G suffixes; default 1G. Specify the amount of memory that will be left to the kernel. Note that KERNEL_MEM will have effect only when some of the other limits have to be calculated (are not explicitly specified).
MACHINE_LIMIT: Non-negative integer, use one of the M or G suffixes. Specify the memory limit for the machine slice.
NUMA_OVERFLOW: Boolean, default is False. Specify whether the usage of non-interface-local CPUs for StorPool is allowed or not.
SERVERS: Integer between 0 and 4. Specify the amount of server instances running on the machine. If not specified, the tool will detect if storpool_server is installed and how many instances are configured in the initialized disks (check with storpool_initdisk --list). If StorPool disks are not initialized the tool will exit with an error.
SET_CACHE_SIZE: Boolean, default is True. Specify whether the tool should calculate and set appropriate cache sizes for storpool_server instances in CACHEDIR. If set to 0 (False) the tool will oblige to the sizes set in storpool.conf and use them instead of calculating and setting them. Usable on server and hyperconverged setups.
SET_MEMSW: Boolean, default is True. Specify whether to set memory.memsw.limit in the cgconfig file.
SP_ALLOC_LIMIT: Non-negative integer, use one of the M or G suffixes. Specify the memory limit for the storpool/alloc slice. If not specified it will be calculated.
SP_COMMON_LIMIT: Non-negative integer, use one of the M or G suffixes. Specify the memory limit for the storpool/common slice. If not specified it will be calculated. On server nodes, the calculation requires StorPool disks to be initialized.
SYSTEM_LIMIT: Non-negative integer, use one of the M or G suffixes; default is 2G. Specify the memory limit for the system slice.
USER_LIMIT: Non-negative integer, use one of the M or G suffixes; default is 2G. Specify the memory limit for the user slice; will be ignored on non-systemd machines.