No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

SmartMulti-Tenant Feature Guide for Block

OceanStor V5 Series V500R007

This document is applicable to OceanStor 5110 V5, 5110F V5, 5300 V5, 5300F V5, 5500 V5, 5500F V5, 5600 V5, 5600F V5, 5800 V5, 5800F V5, 6800 V5, 6800F V5, 18500 V5, 18500F V5, 18800 V5, and 18800F V5. This document describes the implementation principles and application scenarios of the SmartMulti-Tenant feature. Also, it explains how to configure and manage SmartMulti-Tenant.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Modifying the Advanced Properties of a LUN

Modifying the Advanced Properties of a LUN

This operation enables you to configure the prefetch policy and cache policy of a LUN.

Prerequisites

At least one LUN has been created on the storage system.

Context

Super administrators, administrators, SAN resource administrators, and vStore administrators can modify the advanced properties of a LUN.

Procedure

  1. Log in to DeviceManager.
  2. Go to the LUN page.

    The operation path varies with user types:

    • System user: Click vStore, select the desired vStore, and click Details to go to the vStore view. Choose Provisioning > LUN.
    • vStore user: In the vStore view, choose Provisioning > LUN.

  3. Select the LUN whose properties you want to modify and click Properties.

    The Properties of LUN dialog box is displayed.

  4. Configure the advanced properties of the LUN.

    1. Click the Advanced tab.
    2. Configure the advanced properties of the LUN. Table 5-3 lists related parameters.
    NOTE:

    For PE LUNs, you can only modify its owning controller.

    Table 5-3 Advanced properties of the LUN parameters

    Parameter

    Description

    Setting

    Owning Controller

    Owning controller of a LUN. You are advised to allocate LUNs to controllers for load balancing.

    Select an owning controller based on the site requirements.

    NOTE:

    For a four-controller storage system, after a LUN is created, its owning controller can switch between only paired controllers, that is, between controller A and controller B, or between controller C and controller D.

    For example, if you select CTE0.A as the owning controller when creating a LUN, you can select only CTE0.A or CTE0.B as LUN's owning controller when modifying the LUN's advanced properties.

    Working Controller

    Working controller of a LUN. Controller that is used to process read/write requests of LUNs and provide services. Only the working controller can process I/Os on LUNs. If hosts send I/Os to a non-working controller, the I/Os are forwarded to the working controller for processing.

    [Example]

    CTE0.A

    Read Policy

    Data read policy of a cache.

    The system supports the following read policies.

    • Resident: For random cache access. Data is retained in cache the longest to improve the read hit ratio.
    • Default: For regular cache access. Keep balance between read hit ratio and disk access performance.
    • Recycle: For sequential cache access. The idle cache resources are released for other access requests.

    [Example]

    Recycle

    [Default value]

    Default

    Write Policy

    Data write policy of a cache.

    The system supports the following write policies.

    • Resident: For random cache access. Data is retained in cache the longest to improve the write hit ratio.
    • Default: For regular cache access. Keep balance between write hit ratio and disk access performance.
    • Recycle: For sequential cache access. The idle cache resources are released for other access requests.

    [Example]

    Recycle

    [Default value]

    Default

    Prefetch Policy

    Data read mode of a LUN. Before reading data from a LUN, the storage system reads the data from the hard disks to the cache based on the preset policy. The policies include:

    • No prefetch: The storage system reads data based on the read length specified in the I/O request.

      As a low read hit ratio may lead to performance degradation, No prefetch is recommended for random read services.

    • Intelligent prefetch: Smart prefetch analyzes whether the requested data is sequential. If it is, the data following the currently requested data is prefetched from disks to the cache to improve the cache hit ratio. If they are not, the data is read directly from hard disks.
    • Constant prefetch: A constant length of data (user-definable, ranging from 0 to 1024 KB) is read from hard disks every time when the cache reads data from the disks.
    • Variable prefetch: The cache reads data from disks based on a multiple (user-definable, ranging from 0 to 1024) of the read length specified in the I/O request.

    [Example]

    Intelligent prefetch

    Thin LUN Alarm Threshold

    This parameter is only valid when the selected LUN is a thin LUN and the operating system of the application server that owns the LUN is Windows Server 2012.

    Once this parameter is enabled, the application server will receive a threshold alarm when the ratio of the used capacity to total capacity of the LUN exceeds the configured Alarm Threshold (%).

    [Value range]

    50 to 99

    [Default value]

    90

    LUN Write Policy

    The LUN write policy can be:

    • Write back: Data is written onto the cache. The cache schedules the data and writes the data to disks.
    • Write through: Data is directly written onto disks without passing the cache.
    NOTE:

    Writing data onto the cache is fast. Therefore, write back delivers better write performance than write through.

    [Example]

    Write back

    [Default value]

    • The default value of eDevLUN is write through.
    • The default value of local LUN is write back.
    NOTE:

    After a masqueraded eDevLUN created, you cannot modify its LUN write policy. You can modify the policy after you manually take over the masqueraded eDevLUN through CLI.

  5. Confirm the configuration of the advanced properties of a LUN.

    1. Click OK.

      The Execution Result dialog box is displayed, indicating that the operation succeeded.

    2. Click Close.

Translation
Download
Updated: 2019-07-11

Document ID: EDOC1000181478

Views: 29672

Downloads: 182

Average rating:
This Document Applies to these Products
Related Documents
Related Version
Share
Previous Next