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Object storage: S3, OSS, and owned topology

Storage class, small-object tax, minimum duration, requests, retrieval, egress, resource packages, and reliable-topology break-even for object storage.
Important

Snapshot: 2026-08-22 · AWS us-east-1 · Alibaba Cloud China mainland · 1 USD = 6.7817 CNY. Capacity rates, request policy, free allowances, and packages are time-sensitive. Self-hosted crossings exclude labor, software licenses, migration, and business-loss risk.

Direct answer

Object-storage capacity is now cheap and surprisingly close across providers. The bill diverges elsewhere:

monthly object cost=billable capacity+requests+retrieval+minimum-duration penalty+replication+internet and cross-region transfer+management features \begin{aligned} \text{monthly object cost} ={}& \text{billable capacity} + \text{requests} \\ &+ \text{retrieval} + \text{minimum-duration penalty} \\ &+ \text{replication} + \text{internet and cross-region transfer} \\ &+ \text{management features} \end{aligned}

For self-hosting, the corresponding denominator is not raw disk TB:

raw requirement=logical data×EC or replica overhead×free-space reserve×site copies+spares+replication network \begin{aligned} \text{raw requirement} ={}& \text{logical data} \times \text{EC or replica overhead} \\ &\times \text{free-space reserve} \times \text{site copies} \\ &+ \text{spares} + \text{replication network} \end{aligned}

That is why object-storage economics do not have one universal “cloud exit size.” The first question is the minimum reliable topology.

Current capacity rates

Storage class AWS us-east-1 CNY equivalent Alibaba OSS LRS
Standard $0.023/GB-month ¥0.156 ¥0.120
Infrequent access $0.0125 ¥0.0848 ¥0.080
Glacier Instant / Archive $0.004 ¥0.0271 ¥0.033
Glacier Flexible / Cold Archive $0.0036 ¥0.0244 ¥0.015
Deep Archive / Deep Cold Archive $0.00099 ¥0.0067 ¥0.0075

The rows are price-adjacent, not service-equivalent. Retrieval latency, availability, durability topology, restore workflow, and feature semantics differ.

The small-object tax

Cold tiers often bill a minimum object size:

Service class Minimum billable object Minimum storage duration Extra metadata
S3 Standard-IA / One Zone-IA 128 KB 30 days
S3 Glacier Instant 128 KB 90 days
S3 Glacier Flexible / Deep Archive object bytes 90 / 180 days 40 KB/object
OSS IA / Archive / Cold / Deep Cold 64 KB 30 / 60 / 180 / 180 days product-specific

A 1 KB object can therefore consume 128× or 64× its logical size on the bill; a 10 KB object consumes 12.8× or 6.4×. Before moving data to a colder tier, measure object-count distribution, average and percentile size, overwrite/delete rate, and retention—not just total TB.

Activity meters

Requests

Snapshot reference rates:

  • S3 Standard PUT/COPY/POST/LIST: $0.005 / 1,000 requests.
  • S3 Standard GET: $0.0004 / 1,000 requests.
  • OSS Standard: first 5 million PUT and 20 million GET per region-month free, then ¥0.01 / 10,000; IA/Archive PUT/GET commonly ¥0.10 / 10,000.
  • OSS Deep Cold PUT: ¥3.50 / 10,000.

Request policy can change quickly, and console browsing itself can issue GET or LIST requests. High object count can matter even when capacity is small.

Retrieval and early deletion

Snapshot examples:

  • S3 Standard-IA retrieval: $0.01/GB; Glacier Instant: $0.03/GB.
  • OSS IA: ¥0.0325/GB; Archive: ¥0.06/GB; Cold Archive standard retrieval: ¥0.06/GB; Deep Cold standard: ¥0.018/GB.

Deleting, overwriting, or transitioning before the minimum duration can charge the remaining term. An archive restore can also create a temporary hot copy that is billed while accessible.

Transfer: the exit and delivery meter

Path Snapshot price
AWS aggregate internet egress first 100 GB free; next 10 TB $0.09/GB (¥0.610/GB)
AWS same-region cross-AZ commonly $0.01/GB each direction
Alibaba ECS internet egress, Hangzhou ¥0.80/GB
Alibaba OSS busy / off-peak internet egress ¥0.50 / ¥0.25 per GB
Alibaba OSS to CDN origin ¥0.15/GB

The same download has a different price from ECS, OSS busy time, OSS off-peak, or CDN. Draw the full data path before pricing. For provider exit, also check documented waiver eligibility and operational lead time; a conditional waiver is not the same as a zero-rate default.

Packages and commitment risk

Alibaba OSS Standard LRS 100 GB illustrates the package ladder:

Purchase Total / equivalent Relative to PAYG
PAYG capacity ¥12/month 100%
Monthly package ¥11/month 91.7%
Six-month package ¥54.78 total about 76.1% monthly equivalent
One-year package ¥99 total 68.8% monthly equivalent

Unused capacity expires; region, redundancy type, and meter mismatch can prevent deduction. A package lowers nominal unit price only when its scope and usage fit.

Self-hosting begins with topology

The released scenario uses 75% erasure-code efficiency, 80% maximum safe fill, 5% spare-drive inventory, 5% monthly data change, and one practical 1 Gbps port per 100 TB/month of remote replication.

Topology Minimum nodes / sites What it can represent
Four-node lower bound 4 / one site Historical capacity floor; not a current full production baseline
Eight-node single site 8 / one site Current production host lower bound; node/disk failure domain
Eight-node dual site 16 / two sites Complete remote copy plus replication network
Eight-node three site 24 / three sites Conservative multi-failure-domain approximation
Backblaze-style Vault 20 / 20 racks 17+3 erasure coding across rack failure domains

None is automatically equivalent to S3 Standard’s service level. Durability, availability, API semantics, operations, audit, and recovery must be tested separately.

Unit cost by topology

Logical capacity Eight-node single site Dual site Three site 20-rack Vault
100 TB ¥0.1786/GB-month ¥0.4822 ¥0.7759 ¥1.0005
200 TB ¥0.0893 ¥0.2411 ¥0.3879 ¥0.5002
500 TB ¥0.0357 ¥0.0964 ¥0.1552 ¥0.2001
1 PB ¥0.0179 ¥0.0482 ¥0.0776 ¥0.1001
2 PB ¥0.0145 ¥0.0346 ¥0.0550 ¥0.0500
5 PB ¥0.0113 ¥0.0301 ¥0.0481 ¥0.0254
10 PB ¥0.0111 ¥0.0280 ¥0.0451 ¥0.0181

At 100 TB the eight-node pool is mostly empty. Around 200 TB it approaches an OSS one-year package; at 1 PB its single-site capacity cost is about one fifth of that package. Adding sites changes the answer because hardware and replication network are duplicated.

First and durable capacity crossings

Owned topology AWS S3 Standard list Alibaba OSS PAYG Alibaba OSS one-year package
Four-node single-site lower bound 55 TB 71 TB 95 TB
Eight-node single-site production baseline 115 TB 149 TB 199 TB
Eight-node dual site 310 TB 402 TB 536 TB
Eight-node three site, first / durable 498 / 498 TB 647 / 647 TB 863 / 1,223 TB
20-node / 20-rack Vault 642 TB 834 TB 1,112 TB

These are capacity plus replication-network material crossings. S3/OSS requests, retrieval, and small-object overhead are excluded on the cloud side; commercial software, support, load balancers, security, and internal labor are excluded on the owned side.

Sensitivity versus OSS one-year package

Change Eight-node single Dual site Three-site durable
Baseline 199 TB 536 TB 1,223 TB
Hardware -25% 169 TB 476 TB 1,047 TB
Hardware +25% 229 TB 597 TB 1,399 TB
Safe fill 60% 199 TB 536 TB 2,363 TB
Monthly change 20% 199 TB 1,047 TB 7,665 TB
High facility price 224 TB 587 TB 1,300 TB

Single-site capacity is insensitive to write churn; multi-site storage is not. High-churn data can make network replication dominate and may belong in a database, block store, or shared filesystem instead.

Historical insight

S3 Standard fell from $0.15/GB-month in 2006 to $0.023 in 2016, then stayed flat through the snapshot. Alibaba OSS Standard directory price reached ¥0.12 in 2018; a durable public effective rate of ¥0.09 appeared in 2024. Capacity followed a hardware-like early decline, then became a platform meter. Egress and activity did not follow the same curve. See Cloud price history.

Decision zones

Workload Baseline tendency
<100–200 TB, uncertain growth Cloud object storage avoids the minimum pool
~0.2 PB+, one-site capacity need Eight-node owned capacity enters the economic range
~0.5 PB+, two-site copy Formal owned comparison becomes worthwhile
~0.9–1.3 PB+, three-site / rack fault domains Reliable-topology owned economics can cross normal cloud capacity rates
20–25 TB/month+ stable delivery Compare fixed transit/CDN path against per-GB egress separately
Global edge, DDoS, volatile demand Keep CDN and elastic edge even if origin capacity is owned

Cloud exit does not require rejecting CDN, edge, or managed security. A common efficient design owns stable origin capacity and continues buying statistically pooled distribution.

Boundaries

  • Capacity crossings are not SLA or durability certifications.
  • Four-node MinIO is retained only as a lower-bound reference.
  • Commercial object software and internal operations are excluded from the baseline.
  • DHH’s observed S3 contract uses billed footprint; primary logical data gives a different denominator.
  • Request policy, packages, and prices can change after 2026-08-22.

Data and sources