Large Object Uploads

Overview

Individual objects in Polystack Object Storage are limited to 5 GB per upload request. Files larger than 5 GB must be split into segments and uploaded as a Large Object — either a Static Large Object (SLO) or Dynamic Large Object (DLO). Both produce a manifest object that transparently concatenates segments when downloaded.

Prerequisites

An active Polystack account with appropriate permissions
Access to the Polystack Dashboard or CLI configured with credentials
API credentials sourced (source openrc.sh)

SLO vs DLO Comparison

Method	Manifest	Best For	Segment Discovery
SLO (Static Large Object)	Explicit JSON manifest listing each segment	Large files with known segments	Explicit — you define each segment path
DLO (Dynamic Large Object)	Object with `X-Object-Manifest` header	Streaming uploads of unknown total size	Automatic — by name prefix convention

Static Large Object (SLO)

Use SLO when the complete file is available before upload begins.

Split the file into segments

Split file into 1 GB segments

split -b 1G large-backup.tar.gz large-backup.tar.gz.part-

Create a segments container

Create dedicated segments container

openstack container create app-backups-segments

Upload each segment

Upload all segments

for f in large-backup.tar.gz.part-*; do
  openstack object create app-backups-segments "$f"
done

Build and upload the SLO manifest

Collect the ETag of each segment (shown in the upload output) and create a manifest:

manifest.json

[
  {
    "path": "app-backups-segments/large-backup.tar.gz.part-aa",
    "etag": "<etag-from-upload>",
    "size_bytes": 1073741824
  },
  {
    "path": "app-backups-segments/large-backup.tar.gz.part-ab",
    "etag": "<etag-from-upload>",
    "size_bytes": 524288000
  }
]

Upload the manifest with the multipart-manifest query parameter:

Create SLO manifest

curl -X PUT \
  -H "X-Auth-Token: $OS_TOKEN" \
  -H "Content-Type: application/json" \
  --data-binary @manifest.json \
  "https://object.<your-domain>/v1/<account>/app-backups/large-backup.tar.gz?multipart-manifest=put"

The large object is now accessible at app-backups/large-backup.tar.gz and downloads transparently concatenate all segments.

Dynamic Large Object (DLO)

Use DLO for streaming uploads where the total object size is not known in advance.

Upload segments with a common prefix

Upload each segment with a naming convention that groups them by prefix:

Upload DLO segments

openstack object create app-backups large-backup/segment-0001
openstack object create app-backups large-backup/segment-0002
openstack object create app-backups large-backup/segment-0003

Create the DLO manifest object

Create a zero-byte manifest object pointing to the segment prefix:

Create DLO manifest

curl -X PUT \
  -H "X-Auth-Token: $OS_TOKEN" \
  -H "X-Object-Manifest: app-backups/large-backup/" \
  -H "Content-Length: 0" \
  "https://object.<your-domain>/v1/<account>/app-backups/large-backup"

Accessing app-backups/large-backup transparently returns all segments concatenated in alphabetical order.

Download a Large Object

Downloading a large object (SLO or DLO) is transparent — use the same commands as a normal object:

Download large object

openstack object save app-backups large-backup.tar.gz

The proxy server automatically retrieves and concatenates all segments.

Next Steps

Upload Objects

Standard object upload for files under 5 GB

Versioning

Enable versioning on containers that hold large objects

Troubleshooting

Resolve large object upload timeouts and manifest errors

Storage Policies

Choose the right storage policy for large object containers

Core Services

Other Services

Overview

SLO vs DLO Comparison

Static Large Object (SLO)

Split the file into segments

Create a segments container

Upload each segment

Build and upload the SLO manifest

Dynamic Large Object (DLO)

Upload segments with a common prefix

Create the DLO manifest object

Download a Large Object

Next Steps

Upload Objects

Versioning

Troubleshooting

Storage Policies

​Overview

​SLO vs DLO Comparison

​Static Large Object (SLO)

Split the file into segments

Create a segments container

Upload each segment

Build and upload the SLO manifest

​Dynamic Large Object (DLO)

Upload segments with a common prefix

Create the DLO manifest object

​Download a Large Object

​Next Steps

Upload Objects

Versioning

Troubleshooting

Storage Policies

Overview

SLO vs DLO Comparison

Static Large Object (SLO)

Dynamic Large Object (DLO)

Download a Large Object

Next Steps