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    PolarDB:billing rules for backup storage (beyond the free quota)

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    PolarDB:billing rules for backup storage (beyond the free quota)

    Last Updated:Mar 30, 2026

    Backup and recovery features are free to use, but backup files consume storage space. PolarDB provides a free quota for backup storage — usage beyond that quota is billed on a pay-as-you-go basis. Backup storage includes level-1 backup files (snapshots), level-2 backup files, and log backup files. Retention period and backup frequency directly affect how much storage you consume.

    PolarDB also offers storage plans to reduce backup storage costs.

    The following figure shows the backup policies by product edition.

    image
    PSL4/PSL5 storage classes support level-2 backups. Level-2 backup data is derived from level-1 backups and is suited for long-term, low-cost retention — though recovery from level-2 backups is slower than from level-1 backups. PL0, PL1, PL2, PL3, and AutoPL ESSDs do not support level-2 backups.

    Free quota

    Each backup type has a free quota. Charges apply only to storage that exceeds the quota.

    Enterprise Edition

    Backup type Free quota
    Level-1 backup Subscription (billed by storage space): Storage capacity × 50%<br>Pay-as-you-go (billed by storage usage): Storage usage × 50%
    Level-2 backup None
    Log backup 100 GB
    To check your database storage usage, log on to the PolarDB console. On the Basic Information page of the cluster, find the Database Storage Usage value in the Distributed Storage section.

    Standard Edition

    Standard Edition clusters support multiple storage classes. Supported backup types vary by storage class.

    Storage class Backup type Free quota
    PL0, PL1, PL2, PL3, and AutoPL ESSDs Level-1 backup Storage capacity × 50%
    Log backup 100 GB
    PSL4/PSL5 Level-1 backup Subscription (billed by storage space): Storage capacity × 50%<br>Pay-as-you-go (billed by storage usage): Storage usage × 50%
    Level-2 backup None
    Log backup 100 GB
    To check your database storage usage, log on to the PolarDB console. On the Basic Information page of the cluster, find the Database Storage Usage value in the Distributed Storage section.

    Pricing

    Enterprise Edition

    Level-1 backup

    Storage class Chinese mainland Hong Kong (China) and regions outside China Hourly fee formula
    PSL5 USD 0.000464 per GB-hour

    USD 0.0000455041 per GB-hour

    USD 0.0000325029 per GB-hour

    USD 0.00004523 per GB-hour

    USD 0.00003231 per GB-hour

    USD 0.0000455 per GB-hour

    USD 0.0000325 per GB-hour

    USD 0.0000455 per GB-hour

    USD 0.0000325 per GB-hour

    USD 0.0000455 per GB-hour

    USD 0.0000325 per GB-hour

    USD 0.000433 per GB-hour

    USD 0.0003 per GB-hour

    USD 0.000650 per GB-hour

    USD 0.000464 per GB-hour

    		 USD 0.000650 per GB-hour (Total size of level-1 backups − Free quota) × Unit price per hour
    PSL4 USD 0.0003 per GB-hour USD 0.000433 per GB-hour (Total size of level-1 backups − Free quota) × Unit price per hour

    Deployment types covered (PSL5 and PSL4 apply the same price regardless of deployment): dual-zone (hot standby storage cluster enabled), dual-zone (hot standby storage cluster and hot standby compute cluster enabled), three-zone (hot standby storage cluster and logger node enabled), and single-zone (hot standby storage cluster disabled).

    Example: PSL5 in the Chinese mainland. Total size of level-1 backups (snapshots): 700 GB. Database storage usage: 1,000 GB.(1,000 GB - 100 GB) × USD 0.00004523 per GB-hour = USD 0.040707 per hour[700 GB - (1,000 GB × 50%)] × USD 0.00003231 per GB-hour = USD 0.006462 per hour(1,000 GB - 100 GB) × USD 0.0000325 per GB-hour + 500 MB / 1,024 × USD 0.075 per GB = USD 0.0659 per hour(1,000 GB - 100 GB) × USD 0.0000325 per GB-hour = USD 0.02925 per hour1000 GB × USD 0.0000325 per GB-hour + 500 MB / 1024 × USD 0.075 per GB = USD 0.0691 per hour1,000 GB × USD 0.0000325 per GB-hour = USD 0.0325 per hour[700 GB - (1000 GB × 50%)] × USD 0.000464 per GB-hour = USD 0.0928 per hour

    Hourly fee = [700 GB − (1,000 GB × 50%)] × USD 0.000464 per GB-hour = USD 0.0928 per hour

    Level-2 backup and log backup

    For single-region backups, charges are based on backup storage capacity. For cross-region backups, charges include both backup storage and the network traffic generated during replication.

    Single-region backup

    Backup type Chinese mainland Hong Kong (China) and regions outside China Hourly fee formula
    Level-2 backup USD 0.0000325 per GB-hour USD 0.0000455 per GB-hour Total size of level-2 backups × Unit price per hour
    Log backup USD 0.0000325 per GB-hour USD 0.0000455 per GB-hour (Total size of log backups − 100 GB) × Unit price per hour

    Example 1: Level-2 backup in the Chinese mainland. Total size: 1,000 GB.

    Hourly fee = 1,000 GB × USD 0.0000325 per GB-hour = USD 0.0325 per hour

    Example 2: Log backup in the Chinese mainland. Total size: 1,000 GB.

    Hourly fee = (1,000 GB − 100 GB) × USD 0.0000325 per GB-hour = USD 0.02925 per hour

    Cross-region backup

    Backup type Billable item Chinese mainland Hong Kong (China) and regions outside China Hourly fee formula
    Level-2 backup Backup storage USD 0.0000325 per GB-hour USD 0.0000455 per GB-hour Total size of level-2 backups × Unit price per hour + Cross-region network traffic fee
    Network traffic USD 0.075 per GB USD 0.075 per GB See Network fees for details
    Log backup Backup storage USD 0.0000325 per GB-hour USD 0.0000455 per GB-hour (Total size of log backups − 100 GB) × Unit price per hour + Cross-region network traffic fee
    Network traffic USD 0.075 per GB USD 0.075 per GB See Network fees for details
    Cross-region backups are billed daily. The prices above are expressed as hourly rates for reference. Fees for cross-region backups appear in Data Disaster Recovery bills.

    Example 1: Cross-region level-2 backup between regions in the Chinese mainland. Total size: 1,000 GB. Network traffic: 500 MB.

    Hourly fee = 1,000 GB × USD 0.0000325 per GB-hour + 500 MB ÷ 1,024 × USD 0.075 per GB = USD 0.0691 per hour

    Example 2: Cross-region log backup between regions in the Chinese mainland. Total size: 1,000 GB. Network traffic: 500 MB.

    Hourly fee = (1,000 GB − 100 GB) × USD 0.0000325 per GB-hour + 500 MB ÷ 1,024 × USD 0.075 per GB = USD 0.0659 per hour

    Standard Edition

    Standard Edition clusters support multiple storage classes. Pricing varies by storage class.

    PL0, PL1, PL2, PL3, and AutoPL ESSDs

    Backup type Chinese mainland Hong Kong (China) and regions outside China Hourly fee formula
    Level-1 backup USD 0.00003231 per GB-hour USD 0.00004523 per GB-hour (Total size of level-1 backups − Free quota) × Unit price per hour
    Log backup USD 0.0000325029 per GB-hour USD 0.0000455041 per GB-hour (Total size of log backups − 100 GB) × Unit price per hour

    Example 1: Level-1 backup in the Chinese mainland. Total size: 700 GB. Database storage usage: 1,000 GB.

    Hourly fee = [700 GB − (1,000 GB × 50%)] × USD 0.00003231 per GB-hour = USD 0.006462 per hour

    Example 2: Log backup in the Chinese mainland. Total size: 1,000 GB.

    Hourly fee = (1,000 GB − 100 GB) × USD 0.00004523 per GB-hour = USD 0.040707 per hour

    PSL4/PSL5

    Level-1 backup

    Storage class Chinese mainland Hong Kong (China) and regions outside China Hourly fee formula
    PSL5 USD 0.000464 per GB-hour USD 0.000650 per GB-hour (Total size of level-1 backups − Free quota) × Unit price per hour
    PSL4 USD 0.0003 per GB-hour USD 0.000433 per GB-hour (Total size of level-1 backups − Free quota) × Unit price per hour

    Deployment types covered: same as Enterprise Edition — dual-zone, three-zone, and single-zone deployments all apply the same price.

    Example: PSL5 in the Chinese mainland. Total size of level-1 backups (snapshots): 700 GB. Database storage usage: 1,000 GB.

    Hourly fee = [700 GB − (1,000 GB × 50%)] × USD 0.000464 per GB-hour = USD 0.0928 per hour

    Level-2 backup and log backup

    Pricing is the same as Enterprise Edition PSL4/PSL5. See Level-2 backup and log backup above for single-region and cross-region rates and formulas.

    Check backup storage usage

    Check level-1 and data backup size

    PSL4/PSL5

    PSL4/PSL5

    1. Log on to the PolarDB console.

    2. Select your cluster.

    3. Go to Settings and Management > Backup and Restoration.

    image
    The Physical Size of Level-1 Backups value (part ①) is the sum of dedicated physical storage occupied by all level-1 backup sets. This is the billable value.
    The Logical Size of Backups value (part ②) shows the logical size of a backup set. This value is not billed.
    Cluster data and level-1 backup files (snapshots) can share the same physical data block, which is billed only once.

    For more information, see Backup and restoration FAQ.

    PL0, PL1, PL2, PL3, and AutoPL ESSDs

    1. Log on to the PolarDB console

    2. Choose your cluster.

    3. Navigate to Settings and Management > Backup and Restoration.

    image

    Note

    • The Physical Size of Level-1 Backups value of the PolarDB cluster is the sum of the dedicated physical storage occupied by all level-1 backup sets, as shown in part ①. The actual storage space occupied by level-1 backup files is based on this value.

    • The Logical Size of Backups value of the PolarDB cluster indicates the logical size of a backup set, as shown in part ②. This size is not billed.

    • The data of the PolarDB cluster and multiple level-1 backup sets (snapshots) can be stored in the same physical data block that is billed only once.

    For more information about data backup, see FAQ.

    Check level-2 backup size

    1. Log on to the PolarDB console.

    2. Select your cluster.

    3. Go to Settings and Management > Backup and Restoration. The total size of level-2 backup files is the sum of each individual file.

    2

    Check log backup size

    The total size of log backup files is the sum of each individual file.

    日志大小

    Storage plans

    Storage plans offset the storage usage of level-1 backups (or data backups), level-2 backups, and log backups.

    Storage plans also offset cluster storage and cold data archiving usage.

    Pricing

    Storage plan prices vary by subscription duration and capacity. Larger capacity and longer duration give better value. See the price comparison table for details.

    How storage plans offset backup usage

    A storage plan provides a fixed hourly quota. For example, a 100 GB storage plan provides 100 GB per hour to offset backup storage usage.

    The offset factor determines how much backup storage each 1 GB of plan capacity covers. A lower offset factor means each plan gigabyte covers more backup storage.

    Enterprise Edition

    Backup type Offset factor (Chinese mainland) Offset factor (Hong Kong (China) and regions outside China) Backup storage covered by 1 GB of plan (Chinese mainland) Backup storage covered by 1 GB of plan (Hong Kong (China) and regions outside China)
    Level-1 backups (PSL5) 0.617 — 1 ÷ 0.617 = 1.62 GB —
    Level-1 backups (PSL4) 0.40 — 1 ÷ 0.40 = 2.5 GB —
    Level-2 backup storage 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Log backup storage 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Level-2 backup includes backup sets permanently retained in the cluster recycle bin.
    Storage plans cannot offset level-2 cross-region backup storage costs.

    Standard Edition

    PL0, PL1, PL2, PL3, and AutoPL Enterprise SSDs (ESSDs)

    PL0, PL1, PL2, PL3, and AutoPL ESSDs

    Backup type Offset factor (Chinese mainland) Offset factor (Hong Kong (China) and regions outside China) Backup storage covered by 1 GB of plan (Chinese mainland) Backup storage covered by 1 GB of plan (Hong Kong (China) and regions outside China)
    Data backups 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Log backup storage 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Level-2 backup includes backup sets permanently retained in the cluster recycle bin.
    Storage plans cannot offset level-2 cross-region backup storage costs.
    PSL4/PSL5

    PSL4/PSL5

    Backup type Offset factor (Chinese mainland) Offset factor (Hong Kong (China) and regions outside China) Backup storage covered by 1 GB of plan (Chinese mainland) Backup storage covered by 1 GB of plan (Hong Kong (China) and regions outside China)
    Level-1 backups (PSL5) 0.617 — 1 ÷ 0.617 = 1.62 GB —
    Level-1 backups (PSL4) 0.40 — 1 ÷ 0.40 = 2.5 GB —
    Level-2 backup storage 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Log backup storage 0.043 0.054 1 ÷ 0.043 = 23.26 GB 1 ÷ 0.054 = 18.52 GB
    Level-2 backup includes backup sets permanently retained in the cluster recycle bin.
    Storage plans cannot offset level-2 cross-region backup storage costs.

    Example: storage plan offset calculation

    The following example shows how a 50 GB storage plan offsets backup storage usage across multiple clusters.

    Cluster configuration:

    Cluster Edition Hot standby storage cluster Billing method (compute) Storage class Storage billing method Cluster storage usage Level-1/data backup usage Level-2 backup usage Log backup usage
    A RDS Cluster Edition Enabled Subscription PSL5 Subscription 2.76 GB (subscribed: 50.00 GB) 322.00 MB (free quota: ~25 GB) 2.45 GB 70 GB
    C RDS Cluster Edition Disabled Pay-as-you-go PSL5 Pay-as-you-go 100 GB 3.21 GB (free quota: ~50 GB) 2.38 GB 219 GB
    E Standard Edition Disabled Subscription PL1 ESSD Subscription 2.38 GB (subscribed: 100.00 GB) 480.00 MB (free quota: ~50 GB) None 79 GB

    How the 50 GB plan is consumed (in offset order):

    1. Level-1 backup usage beyond free quota (Enterprise Edition clusters):

      • Cluster A: within free quota — 0 GB consumed from plan.

      • Cluster C: within free quota — 0 GB consumed from plan.

    2. Level-2 backup usage (Enterprise Edition clusters):

      • Cluster A: 2.45 GB × 0.043 = 0.10535 GB consumed. Plan remaining: 49.89465 GB.

      • Cluster C: 2.38 GB × 0.043 = 0.10234 GB consumed. Plan remaining: 49.79231 GB.

    3. Log backup usage beyond free quota (Enterprise Edition clusters):

      • Cluster A: 70 GB — within the 100 GB free quota. 0 GB consumed.

      • Cluster C: 219 GB − 100 GB = 119 GB beyond free quota. 119 GB × 0.043 = 5.117 GB consumed. Plan remaining: 44.67531 GB.

    4. Data backup usage beyond free quota (Standard Edition clusters):

      • Cluster E: within free quota — 0 GB consumed.

    5. Log backup usage beyond free quota (Standard Edition clusters):

      • Cluster E: 79 GB — within the 100 GB free quota. 0 GB consumed.

    Result: The plan consumed 0.10535 + 0.10234 + 5.117 = 5.32469 GB in total. Remaining plan capacity: 44.67531 GB.

    This example covers only how the storage plan offsets level-1/data backup, level-2 backup, and log backup usage. Cluster storage and cold data archiving usage are not included.

    For storage plan specifications, pricing, and purchase details, see Storage plans.