What Is the Block-Level Migration?
What Is a Block?
In block-level migrations, a block refers to a disk block. A disk block is the minimum logical unit of the file system for managing disk partitions. Disk blocks are similar to clusters in Windows. A block is also the minimum logic unit of disks used by OSs and software. The smallest unit for disk read or write is a sector. A sector is a physical area on the disk. The read and write operations to disk blocks are performed in sectors. Generally, a file is stored in several blocks, and one block maps to several physical sectors.
What Is a Block-Level Migration?
In block-level migrations, file systems are migrated by blocks. If the network is interrupted during the migration, only impacted blocks need to be migrated again after the network recovers. If files are modified during the migration, only modified blocks need to be synchronized after the migration.
In file-level migrations, various tools like TAR and SSH or other transmission protocols are used for remote replication. If a file is changed during decompression or the network is interrupted during migration, the migration will fail. In addition, if a file is changed during incremental data synchronization, the file needs to be synchronized again. In this case, all the blocks of the file must be synchronized. So, the synchronization efficiency is low.
Product Consultation FAQs
- Can I Migrate Physical Servers and VMs from Other Clouds to Huawei Cloud Using SMS?
- Can I Migrate ECSs from Huawei Cloud to On-Premises Environments or Other Clouds Using SMS?
- Can I Ask Huawei Cloud Technical Support to Help Me Migrate Services?
- Can I Migrate Workloads to a DeH, DeC, Kunpeng ECS, or BMS Using SMS?
- Does SMS Support Resumable Data Transfer?
- How Do I Migrate an ECS from One Account to Another?
- How Do I Migrate an ECS from One Region to Another Using SMS?
- Will My Services on the Source Server Be Interrupted During Migration?
- How Do I Create an AK/SK Pair for a Huawei Cloud Account?
- How Do I Create an AK/SK Pair for an IAM User?
- How Do I Migrate a Linux Source Server as a Non-root User?
- What Information Does SMS Collect About Source Servers?
- How Do I Select a Target Server?
- How Do I Create an ECS?
- What Is the Block-Level Migration?
- What are Valid Data Blocks?
- How Does Migration Using SMS Differ from Migration Using IMS?
- Why Is the OS Name of the Target ECS Displayed on the ECS Console Different from That of the Source Server?
- How Do I Determine Whether a Migration Is Complete?
- Can I Migrate Only Some Services on the Source Server?
- Can the Target Server Run a Different Type of OS from the Source Server?
- What Determines the Specifications of a Target Server?
- Which Download Option Should I Choose When I Download the Windows Agent?
- Can I Migrate a Source Server If There Is No Corresponding Image Available on Huawei Cloud?
- How Does SMS Differ from IMS in the Migration Scenario?
- How Do I Display the OS Name of a Target Server on the ECS Console?
- What Are the Snapshots of a Target Server Used for?
- In a Linux File-Level Migration, How Do I Exclude Directories from Migration and Synchronization?
- Will an Incremental Synchronization Overwrite Existing Data on a Launched Target Server?
- How Do I Create a Target Server that Meets the SMS Requirements?
- Can SMS Migrate Self-built Databases, Big Data Services, or Websites Deployed on a Source Server?
- Can the AK/SK of a Federated User (Virtual IAM User) Be Used for Authentication During the SMS-Agent Startup?
- How Do I Synchronize Files in Specific Directories After a Linux File-Level Migration Is Complete?
- Will the Migration Be Affected If the SSH Service Does Not Use Default Port 22 on the Source Server?
- How Do I Obtain the SMS Domain Name?
- How Many Resources Will Be Used for a Linux Block-Level Migration?
- How Do I Configure Data Compression for a Linux Block-Level Migration?
- Do I Need to Activate My Windows OS and Paid Software After the Migration?
- Why Does the Target Server Not Synchronize the Clocks on the Source Server?
- How Do I Set the Number of Concurrent Processes for Linux File-Level Migrations?
- What Are the Differences Between the New SMS Edition and the Old Edition and How Do I Return to the Old Edition?
- Which Directories Are Not Synchronized by Default During Incremental Synchronization on a Linux Server?
- How Do I Verify Data Consistency Between the Source and Target Servers?
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