What technologies are involved in expanding storage on Hong Kong cloud servers? The first step in storage expansion is identifying the type of storage currently in use. Cloud platforms typically offer various storage options, including cloud disks based on distributed storage, local SSDs, and object storage services. The expansion path differs significantly for each storage type.

Cloud disks utilize a network-distributed storage architecture, supporting elastic expansion without downtime. Local SSDs are limited by physical server slots, and expansion often requires data migration. Object storage achieves capacity growth through automatic expansion of bucket space, but access latency is higher than block storage.

Capacity assessment requires a comprehensive analysis of current usage patterns and future needs. The monitoring system needs to provide historical trend data on storage space utilization to identify storage growth patterns during peak business periods. Simultaneously, application-layer IOPS and throughput requirements should be assessed to ensure that the expanded storage performance matches business needs.

Block storage device expansion operations vary depending on the file system type. The commonly used EXT4 file system in Linux systems supports online expansion, which can be completed using the `resize2fs` command. The XFS file system requires the `xfs_growfs` command for dynamic expansion.

# Example of expanding EXT4 file system
resize2fs /dev/vdb1
# Example of expanding XFS file system
xfs_growfs /dev/vdb1

Windows servers use the NTFS file system, and volume expansion can be performed through disk management tools. Cloud platforms typically provide a graphical interface to simplify these operations, but the underlying system commands are still called.

Logical volume management technology provides greater flexibility for storage expansion. LVM allows multiple physical volumes to be combined into volume groups, from which logical volumes are divided. Expansion simply involves adding a new physical volume to the volume group and then expanding the logical volume size.

# LVM expansion process
vgextend vg0 /dev/vdc
lvextend -L +500G /dev/vg0/lv0
resize2fs /dev/vg0/lv0

When local storage needs expansion, data migration becomes a necessary step. Cloud platforms provide snapshot and image functions to simplify this process. After creating a system disk snapshot, a new Hong Kong cloud server with a larger capacity can be created based on that snapshot.

Online migration technology allows services to continue operating during migration. DRBD technology enables real-time synchronization of block devices, and combined with the hot migration capabilities of virtualization platforms, it allows for seamless data migration without impacting business operations.

For large-scale data migrations, a phased strategy can reduce business impact. Non-critical data should be migrated first, and core business data should be migrated only after the migration process has been verified. Strict monitoring of performance metrics is necessary during the migration process to ensure no impact on normal services.

After storage device expansion, the operating system needs to recognize the new capacity. The Linux system triggers the kernel to recognize the new device size by rescanning the SCSI bus.

# Rescan SCSI devices
echo 1 > /sys/class/block/sdb/device/rescan

Partition table updates are a critical step. MBR partition tables support a maximum disk capacity of 2TB; exceeding this limit requires the use of GPT partition tables. The parted tool can be used to adjust the partition table to recognize the expanded capacity.

File system expansion must be performed after partition resizing. Different file systems have varying levels of support for online expansion; EXT4 and XFS support fully online expansion, while some older file systems may require unmounting.

Data consistency is crucial during storage expansion. Database service storage expansion requires special handling and is generally recommended to be performed during off-peak hours, with a full backup completed beforehand.

RAID array expansion involves striping and reassembly, which can be a lengthy rebuild process. During this time, system performance will significantly degrade, and there is a risk of data loss. A strategy combining RAID-level migration and expansion can reduce overall downtime.

Expanding distributed storage systems is more complex. Systems like Ceph and GlusterFS require data rebalancing across multiple nodes, which can lead to temporary performance fluctuations. Properly configured CRUSH rules can optimize data distribution and reduce the performance impact of expansion.

After storage expansion, performance tuning becomes paramount. Adjusting file system mount parameters can optimize performance under specific workloads. The `noatime` parameter reduces metadata updates, improving the performance of read-intensive applications.

Monitoring systems need to update storage-related alarm thresholds. Predictive alarm rules based on the new capacity configuration should be implemented to provide early warnings when space utilization reaches 80%. Simultaneously monitor IOPS and throughput metrics to ensure storage performance meets business needs.

Cloud platform monitoring tools can track changes in storage performance. By analyzing performance data before and after expansion, the effectiveness of the expansion can be verified, providing a reference for future capacity planning. Updating the storage performance baseline should be a standard step in the expansion process.

Experienced operations teams will automate the storage expansion process. Tools such as Terraform are used to write expansion scripts, reducing human error. Automated scripts should include complete verification steps to ensure correct execution at each stage.

Process documentation records the detailed steps and problems encountered during each expansion. This accumulated knowledge provides a reference for subsequent expansions and helps new team members quickly master relevant skills. Standardized checklists ensure no critical steps are missed.

As a core component of cloud infrastructure management, the optimization of storage expansion processes directly impacts business stability and operational efficiency. With the continuous development of storage technology, expansion processes will continue to evolve, moving towards greater automation and security.