Managing I/O modes and priorities

You can manage the internal I/O modes and priorities of the cluster via commands.

Internal I/O includes two modes:

AUTO: Auto mode. Adjusts internal I/O speed automatically based on the current system load.
STATIC: Static adjustment mode. Specifies the maximum rate for internal I/O. The cluster space is divided into the performance tier (perf) and capacity tier (cap), each with independent rate limit settings.

Internal I/O includes data recovery I/O, demotion I/O, and data migration I/O. Each type of internal I/O can be assigned a priority, allowing higher-priority I/O to execute faster. Internal I/O includes three priorities:

INTERNAL_HIGH: High priority
INTERNAL_MID: Medium priority
INTERNAL_LOW: Low priority

The default cluster internal I/O priorities are as follows:

Recovery I/O: INTERNAL_HIGH
Demotion I/O: INTERNAL_MID
Migration I/O: INTERNAL_LOW

Setting internal I/O modes and priorities

The mode and priority of internal I/O can be configured independently.

Procedure

Run the following command on any node in the cluster to set internal I/O modes and priorities:

zbs-meta internal_io update [-h] [--mode <MODE>] [--static_cap_internal_io_speed_limit <STATIC_CAP_INTERNAL_IO_SPEED_LIMIT>] [--static_perf_internal_io_speed_limit <STATIC_PERF_INTERNAL_IO_SPEED_LIMIT>] [--recover <RECOVER>] [--sink <SINK>] [--migrate <MIGRATE>]

Parameter	Description
`-h`	Optional. Displays the help information for the update command.
`--mode <MODE>`	Specifies internal I/O modes: `AUTO`: Auto mode. This is the default mode. `STATIC`: static adjustment mode. Allows setting the same limit for all chunks under meta only. Individual limits cannot be configured for each chunk.
`--static_perf_internal_io_speed_limit <STATIC_PERF_INTERNAL_IO_SPEED_LIMIT>`	Optional, effective only when the mode is set to `STATIC`. Specifies the maximum internal I/O rate for the performance tier (MiB/s). If the mode is set to `AUTO`, this parameter has no effect.
`--static_cap_internal_io_speed_limit <STATIC_CAP_INTERNAL_IO_SPEED_LIMIT>`	Optional, effective only when the mode is set to `STATIC`. Specifies the maximum internal I/O rate for the capacity tier (MiB/s). If the mode is set to `AUTO`, this parameter has no effect.
`--recover <RECOVER>`	Optional, set independently of the mode. Specifies the recovery I/O priority (`INTERNAL_HIGH > INTERNAL_MID > INTERNAL_LOW`). `Note:` If it is not necessary to update the internal I/O priority, it is recommended to keep the cluster's default setting (`INTERNAL_HIGH`).
`--sink <SINK>`	Optional, set independently of the mode. Specifies the demotion I/O priority (`INTERNAL_HIGH` > `INTERNAL_MID` > `INTERNAL_LOW`). `Note:` If it is not necessary to update the internal I/O priority, it is recommended to keep the cluster's default setting (`INTERNAL_MID`).
`--migrate <MIGRATE>`	Optional, set independently of the mode. Specifies the migration I/O priority (`INTERNAL_HIGH` > `INTERNAL_MID` > `INTERNAL_LOW`). `Note:` If it is not necessary to update the internal I/O priority, it is recommended to keep the cluster's default setting (`INTERNAL_LOW`).

Output note

If the command succeeds, no output is displayed.

Querying the current internal I/O modes and priorities

Procedure

Run the following command on any node in the cluster to query the current internal I/O modes and priorities:

zbs-meta internal_io show

Output example

Internal I/O mode: INTERNAL_IO_STATIC
Static cap speed limit: 104.86 MB/s(100.00 MiB/s)
Static perf speed limit: 209.72 MB/s(200.00 MiB/s)
Recover I/O Priority: INTERNAL_HIGH
Sink I/O Priority: INTERNAL_MID
Migrate I/O Priority: INTERNAL_LOW

Session ID                            IP           Current Cap Speed Limit    Cap HW Speed Limit     Current Perf Speed Limit    Perf HW Speed Limit
------------------------------------  -----------  -------------------------  ---------------------  --------------------------  ---------------------
1e654354-e233-4fc3-a5ac-4338bb379bed  10.0.130.82  104.86 MB/s(100.00 MiB/s)  1.56 GB/s(1.46 GiB/s)  209.72 MB/s(200.00 MiB/s)   1.26 GB/s(1.17 GiB/s)
27ddc961-86df-4019-9c5e-9171d42d0f29  10.0.130.84  104.86 MB/s(100.00 MiB/s)  1.56 GB/s(1.46 GiB/s)  209.72 MB/s(200.00 MiB/s)   1.26 GB/s(1.17 GiB/s)
30d56eee-bb9b-4082-a9fa-15a410ec716b  10.0.130.83  104.86 MB/s(100.00 MiB/s)  1.56 GB/s(1.46 GiB/s)  209.72 MB/s(200.00 MiB/s)   1.26 GB/s(1.17 GiB/s)
fcc1166a-0de6-40a3-839b-c71c9d5bd4e4  10.0.130.81  104.86 MB/s(100.00 MiB/s)  1.56 GB/s(1.46 GiB/s)  209.72 MB/s(200.00 MiB/s)   1.26 GB/s(1.17 GiB/s)

Output note

Parameter	Description
`Internal I/O mode`	The Internal I/O Mode.
`Static cap speed limit`	The static capacity tier's internal I/O speed limit.
`Static perf speed limit`	The static performance tier's internal I/O speed limit.
`Recover I/O Priority`	The recovery I/O priority.
`Sink I/O Priority`	The demotion I/O priority.
`Migrate I/O Priority`	The migration I/O priority.
`Current Cap Speed limit`	The current capacity tier's internal I/O speed limit.
`Cap HW Speed limit`	The maximum internal I/O speed determined by the capacity tier hardware.
`Current Perf Speed limit`	The current performance tier's internal I/O speed limit.
`Perf HW Speed limit`	The maximum internal I/O speed determined by the performance tier hardware.

In this article

Setting internal I/O modes and priorities
Querying the current internal I/O modes and priorities