Hello Proxmox Team,
I am experiencing a persistent Garbage Collection failure on Proxmox Backup Server when using an S3-compatible object storage backend.
Environment:
- Proxmox Backup Server version: proxmox-backup-server 4.1.1-1 running version: 4.1.1
- Datastore name: cloud-backup
- Storage backend: S3-compatible Object Storage
- Provider: Contabo Object Storage
- Garbage Collection: scheduled (daily)
Problem Description:
Garbage Collection fails consistently during phase2 when listing chunks from the S3 object store.
No configuration changes were made prior to the issue appearing.
---
Error observed:
2026-01-04T00:00:00+03:00: starting garbage collection on store cloud-backup
2026-01-04T00:00:00+03:00: task triggered by schedule 'daily'
2026-01-04T00:00:01+03:00: Access time update check successful, proceeding with GC.
2026-01-04T00:00:01+03:00: Using access time cutoff 1d 5m, minimum access time is 2026-01-02T20:55:00Z
2026-01-04T00:00:01+03:00: Start GC phase1 (mark used chunks)
2026-01-04T00:00:06+03:00: marked 1% (19 of 1835 index files)
2026-01-04T00:00:XX+03:00: ERROR: failed to list chunk in s3 object store:
failed to parse response body: custom: missing field Name
The garbage collection task stops at phase2 and does not complete.
---
Actions Taken:
- Verified S3 credentials and access permissions
- Confirmed no manual deletion or modification of objects
- Restarted Proxmox Backup Server services
- Retried garbage collection manually
- updated the PBS to the latest version and got the error below:
2026-01-05T15:30:04+03:00: starting garbage collection on store cloud-backup
2026-01-05T15:30:05+03:00: Access time update check successful, proceeding with GC.
2026-01-05T15:30:05+03:00: Using access time cutoff 1d 5m, minimum access time is 2026-01-04T12:25:04Z
2026-01-05T15:30:05+03:00: Start GC phase1 (mark used chunks)
2026-01-05T15:30:26+03:00: marked 1% (19 of 1835 index files)
2026-01-05T15:30:34+03:00: marked 2% (37 of 1835 index files)
2026-01-05T15:30:41+03:00: marked 3% (56 of 1835 index files)
2026-01-05T15:30:42+03:00: marked 4% (74 of 1835 index files)
2026-01-05T15:30:44+03:00: marked 5% (92 of 1835 index files)
2026-01-05T15:30:45+03:00: marked 6% (111 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 7% (129 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 8% (147 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 9% (166 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 10% (184 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 11% (202 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 12% (221 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 13% (239 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 14% (257 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 15% (276 of 1835 index files)
2026-01-05T15:30:50+03:00: marked 16% (294 of 1835 index files)
2026-01-05T15:30:51+03:00: marked 17% (312 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 18% (331 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 19% (349 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 20% (367 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 21% (386 of 1835 index files)
2026-01-05T15:30:54+03:00: marked 22% (404 of 1835 index files)
2026-01-05T15:30:56+03:00: marked 23% (423 of 1835 index files)
2026-01-05T15:30:57+03:00: marked 24% (441 of 1835 index files)
2026-01-05T15:30:57+03:00: marked 25% (459 of 1835 index files)
2026-01-05T15:30:58+03:00: marked 26% (478 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 27% (496 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 28% (514 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 29% (533 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 30% (551 of 1835 index files)
2026-01-05T15:31:00+03:00: marked 31% (569 of 1835 index files)
2026-01-05T15:31:00+03:00: marked 32% (588 of 1835 index files)
2026-01-05T15:31:01+03:00: marked 33% (606 of 1835 index files)
2026-01-05T15:31:01+03:00: marked 34% (624 of 1835 index files)
2026-01-05T15:31:02+03:00: marked 35% (643 of 1835 index files)
2026-01-05T15:31:03+03:00: marked 36% (661 of 1835 index files)
2026-01-05T15:31:03+03:00: marked 37% (679 of 1835 index files)
2026-01-05T15:31:05+03:00: marked 38% (698 of 1835 index files)
2026-01-05T15:31:07+03:00: marked 39% (716 of 1835 index files)
2026-01-05T15:31:09+03:00: marked 40% (734 of 1835 index files)
2026-01-05T15:31:10+03:00: marked 41% (753 of 1835 index files)
2026-01-05T15:31:11+03:00: marked 42% (771 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 43% (790 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 44% (808 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 45% (826 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 46% (845 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 47% (863 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 48% (881 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 49% (900 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 50% (918 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 51% (936 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 52% (955 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 53% (973 of 1835 index files)
2026-01-05T15:31:17+03:00: marked 54% (991 of 1835 index files)
2026-01-05T15:31:22+03:00: marked 55% (1010 of 1835 index files)
2026-01-05T15:31:25+03:00: marked 56% (1028 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 57% (1046 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 58% (1065 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 59% (1083 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 60% (1101 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 61% (1120 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 62% (1138 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 63% (1157 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 64% (1175 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 65% (1193 of 1835 index files)
2026-01-05T15:31:30+03:00: marked 66% (1212 of 1835 index files)
2026-01-05T15:31:32+03:00: marked 67% (1230 of 1835 index files)
2026-01-05T15:31:34+03:00: marked 68% (1248 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 69% (1267 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 70% (1285 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 71% (1303 of 1835 index files)
2026-01-05T15:31:36+03:00: marked 72% (1322 of 1835 index files)
2026-01-05T15:31:38+03:00: marked 73% (1340 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 74% (1358 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 75% (1377 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 76% (1395 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 77% (1413 of 1835 index files)
2026-01-05T15:31:49+03:00: marked 78% (1432 of 1835 index files)
2026-01-05T15:31:57+03:00: marked 79% (1450 of 1835 index files)
2026-01-05T15:32:04+03:00: marked 80% (1468 of 1835 index files)
2026-01-05T15:32:10+03:00: marked 81% (1487 of 1835 index files)
2026-01-05T15:32:14+03:00: marked 82% (1505 of 1835 index files)
2026-01-05T15:32:18+03:00: marked 83% (1524 of 1835 index files)
2026-01-05T15:32:20+03:00: marked 84% (1542 of 1835 index files)
2026-01-05T15:32:21+03:00: marked 85% (1560 of 1835 index files)
2026-01-05T15:32:22+03:00: marked 86% (1579 of 1835 index files)
2026-01-05T15:32:22+03:00: marked 87% (1597 of 1835 index files)
2026-01-05T15:32:23+03:00: marked 88% (1615 of 1835 index files)
2026-01-05T15:32:27+03:00: marked 89% (1634 of 1835 index files)
2026-01-05T15:32:30+03:00: marked 90% (1652 of 1835 index files)
2026-01-05T15:32:32+03:00: marked 91% (1670 of 1835 index files)
2026-01-05T15:32:32+03:00: marked 92% (1689 of 1835 index files)
2026-01-05T15:32:33+03:00: marked 93% (1707 of 1835 index files)
2026-01-05T15:32:33+03:00: marked 94% (1725 of 1835 index files)
2026-01-05T15:32:38+03:00: marked 95% (1744 of 1835 index files)
2026-01-05T15:32:39+03:00: marked 96% (1762 of 1835 index files)
2026-01-05T15:32:40+03:00: marked 97% (1780 of 1835 index files)
2026-01-05T15:32:43+03:00: marked 98% (1799 of 1835 index files)
2026-01-05T15:32:44+03:00: marked 99% (1817 of 1835 index files)
2026-01-05T15:32:45+03:00: marked 100% (1835 of 1835 index files)
2026-01-05T15:32:46+03:00: Start GC phase2 (sweep unused chunks)
2026-01-05T15:32:46+03:00: queued notification (id=10f4a17a-2d4b-42b5-b2fd-eef54aeb6069)
2026-01-05T15:32:46+03:00: TASK ERROR: failed to list chunk in s3 object store: failed to parse response body: custom: missing field `IsTruncated`
The issue persists.
---
Thank you for your support.
I am experiencing a persistent Garbage Collection failure on Proxmox Backup Server when using an S3-compatible object storage backend.
Environment:
- Proxmox Backup Server version: proxmox-backup-server 4.1.1-1 running version: 4.1.1
- Datastore name: cloud-backup
- Storage backend: S3-compatible Object Storage
- Provider: Contabo Object Storage
- Garbage Collection: scheduled (daily)
Problem Description:
Garbage Collection fails consistently during phase2 when listing chunks from the S3 object store.
No configuration changes were made prior to the issue appearing.
---
Error observed:
2026-01-04T00:00:00+03:00: starting garbage collection on store cloud-backup
2026-01-04T00:00:00+03:00: task triggered by schedule 'daily'
2026-01-04T00:00:01+03:00: Access time update check successful, proceeding with GC.
2026-01-04T00:00:01+03:00: Using access time cutoff 1d 5m, minimum access time is 2026-01-02T20:55:00Z
2026-01-04T00:00:01+03:00: Start GC phase1 (mark used chunks)
2026-01-04T00:00:06+03:00: marked 1% (19 of 1835 index files)
2026-01-04T00:00:XX+03:00: ERROR: failed to list chunk in s3 object store:
failed to parse response body: custom: missing field Name
The garbage collection task stops at phase2 and does not complete.
---
Actions Taken:
- Verified S3 credentials and access permissions
- Confirmed no manual deletion or modification of objects
- Restarted Proxmox Backup Server services
- Retried garbage collection manually
- updated the PBS to the latest version and got the error below:
2026-01-05T15:30:04+03:00: starting garbage collection on store cloud-backup
2026-01-05T15:30:05+03:00: Access time update check successful, proceeding with GC.
2026-01-05T15:30:05+03:00: Using access time cutoff 1d 5m, minimum access time is 2026-01-04T12:25:04Z
2026-01-05T15:30:05+03:00: Start GC phase1 (mark used chunks)
2026-01-05T15:30:26+03:00: marked 1% (19 of 1835 index files)
2026-01-05T15:30:34+03:00: marked 2% (37 of 1835 index files)
2026-01-05T15:30:41+03:00: marked 3% (56 of 1835 index files)
2026-01-05T15:30:42+03:00: marked 4% (74 of 1835 index files)
2026-01-05T15:30:44+03:00: marked 5% (92 of 1835 index files)
2026-01-05T15:30:45+03:00: marked 6% (111 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 7% (129 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 8% (147 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 9% (166 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 10% (184 of 1835 index files)
2026-01-05T15:30:46+03:00: marked 11% (202 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 12% (221 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 13% (239 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 14% (257 of 1835 index files)
2026-01-05T15:30:47+03:00: marked 15% (276 of 1835 index files)
2026-01-05T15:30:50+03:00: marked 16% (294 of 1835 index files)
2026-01-05T15:30:51+03:00: marked 17% (312 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 18% (331 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 19% (349 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 20% (367 of 1835 index files)
2026-01-05T15:30:52+03:00: marked 21% (386 of 1835 index files)
2026-01-05T15:30:54+03:00: marked 22% (404 of 1835 index files)
2026-01-05T15:30:56+03:00: marked 23% (423 of 1835 index files)
2026-01-05T15:30:57+03:00: marked 24% (441 of 1835 index files)
2026-01-05T15:30:57+03:00: marked 25% (459 of 1835 index files)
2026-01-05T15:30:58+03:00: marked 26% (478 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 27% (496 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 28% (514 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 29% (533 of 1835 index files)
2026-01-05T15:30:59+03:00: marked 30% (551 of 1835 index files)
2026-01-05T15:31:00+03:00: marked 31% (569 of 1835 index files)
2026-01-05T15:31:00+03:00: marked 32% (588 of 1835 index files)
2026-01-05T15:31:01+03:00: marked 33% (606 of 1835 index files)
2026-01-05T15:31:01+03:00: marked 34% (624 of 1835 index files)
2026-01-05T15:31:02+03:00: marked 35% (643 of 1835 index files)
2026-01-05T15:31:03+03:00: marked 36% (661 of 1835 index files)
2026-01-05T15:31:03+03:00: marked 37% (679 of 1835 index files)
2026-01-05T15:31:05+03:00: marked 38% (698 of 1835 index files)
2026-01-05T15:31:07+03:00: marked 39% (716 of 1835 index files)
2026-01-05T15:31:09+03:00: marked 40% (734 of 1835 index files)
2026-01-05T15:31:10+03:00: marked 41% (753 of 1835 index files)
2026-01-05T15:31:11+03:00: marked 42% (771 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 43% (790 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 44% (808 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 45% (826 of 1835 index files)
2026-01-05T15:31:12+03:00: marked 46% (845 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 47% (863 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 48% (881 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 49% (900 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 50% (918 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 51% (936 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 52% (955 of 1835 index files)
2026-01-05T15:31:13+03:00: marked 53% (973 of 1835 index files)
2026-01-05T15:31:17+03:00: marked 54% (991 of 1835 index files)
2026-01-05T15:31:22+03:00: marked 55% (1010 of 1835 index files)
2026-01-05T15:31:25+03:00: marked 56% (1028 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 57% (1046 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 58% (1065 of 1835 index files)
2026-01-05T15:31:27+03:00: marked 59% (1083 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 60% (1101 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 61% (1120 of 1835 index files)
2026-01-05T15:31:28+03:00: marked 62% (1138 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 63% (1157 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 64% (1175 of 1835 index files)
2026-01-05T15:31:29+03:00: marked 65% (1193 of 1835 index files)
2026-01-05T15:31:30+03:00: marked 66% (1212 of 1835 index files)
2026-01-05T15:31:32+03:00: marked 67% (1230 of 1835 index files)
2026-01-05T15:31:34+03:00: marked 68% (1248 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 69% (1267 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 70% (1285 of 1835 index files)
2026-01-05T15:31:35+03:00: marked 71% (1303 of 1835 index files)
2026-01-05T15:31:36+03:00: marked 72% (1322 of 1835 index files)
2026-01-05T15:31:38+03:00: marked 73% (1340 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 74% (1358 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 75% (1377 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 76% (1395 of 1835 index files)
2026-01-05T15:31:40+03:00: marked 77% (1413 of 1835 index files)
2026-01-05T15:31:49+03:00: marked 78% (1432 of 1835 index files)
2026-01-05T15:31:57+03:00: marked 79% (1450 of 1835 index files)
2026-01-05T15:32:04+03:00: marked 80% (1468 of 1835 index files)
2026-01-05T15:32:10+03:00: marked 81% (1487 of 1835 index files)
2026-01-05T15:32:14+03:00: marked 82% (1505 of 1835 index files)
2026-01-05T15:32:18+03:00: marked 83% (1524 of 1835 index files)
2026-01-05T15:32:20+03:00: marked 84% (1542 of 1835 index files)
2026-01-05T15:32:21+03:00: marked 85% (1560 of 1835 index files)
2026-01-05T15:32:22+03:00: marked 86% (1579 of 1835 index files)
2026-01-05T15:32:22+03:00: marked 87% (1597 of 1835 index files)
2026-01-05T15:32:23+03:00: marked 88% (1615 of 1835 index files)
2026-01-05T15:32:27+03:00: marked 89% (1634 of 1835 index files)
2026-01-05T15:32:30+03:00: marked 90% (1652 of 1835 index files)
2026-01-05T15:32:32+03:00: marked 91% (1670 of 1835 index files)
2026-01-05T15:32:32+03:00: marked 92% (1689 of 1835 index files)
2026-01-05T15:32:33+03:00: marked 93% (1707 of 1835 index files)
2026-01-05T15:32:33+03:00: marked 94% (1725 of 1835 index files)
2026-01-05T15:32:38+03:00: marked 95% (1744 of 1835 index files)
2026-01-05T15:32:39+03:00: marked 96% (1762 of 1835 index files)
2026-01-05T15:32:40+03:00: marked 97% (1780 of 1835 index files)
2026-01-05T15:32:43+03:00: marked 98% (1799 of 1835 index files)
2026-01-05T15:32:44+03:00: marked 99% (1817 of 1835 index files)
2026-01-05T15:32:45+03:00: marked 100% (1835 of 1835 index files)
2026-01-05T15:32:46+03:00: Start GC phase2 (sweep unused chunks)
2026-01-05T15:32:46+03:00: queued notification (id=10f4a17a-2d4b-42b5-b2fd-eef54aeb6069)
2026-01-05T15:32:46+03:00: TASK ERROR: failed to list chunk in s3 object store: failed to parse response body: custom: missing field `IsTruncated`
The issue persists.
---
Thank you for your support.
