Hello! So I created a new job and a small test vm to gather info. I did 3 replications runs and the last 2 failed. Backups are working thoug. Since this would be a large post, I created a pdf with the test cycle. ... Only to find out that those are not allowed on this forum! So I captured the pdf pages... [image: 1784297275075-535e6b06-678a-4228-b109-e6fad5ec97e5-image.jpeg] [image: 1784297294513-9c5c5933-3dc8-4223-983e-7a9c3d884a72-image.jpeg] [image: 1784297307874-e199e8fa-4335-412a-924b-67f482b8bdd2-image.jpeg] [image: 1784297320970-7e8a9103-1a5f-4b7c-b886-2c9364cdd3af-image.jpeg] [image: 1784297331437-18fedc6b-3f83-4165-a6e3-f1586b97c127-image.jpeg] [image: 1784297343300-7c917ab7-31f7-441a-bca8-397fd8653a29-image.jpeg] [image: 1784297353287-921b2af6-5276-4272-818b-6f7a025d6c59-image.jpeg] And the logs from the jobs: { "data": { "mode": "delta", "reportWhen": "always", "backupReportTpl": "mjml" }, "id": "1784293017099", "jobId": "10d0331c-694e-4681-8860-33fef3790552", "jobName": "TESTCRANDBK", "message": "backup", "scheduleId": "bc7b29ce-25b2-4c66-9186-b1d4c314b979", "start": 1784293017099, "status": "success", "tasks": [ { "id": "0mroxztk5-9yuipq34src", "start": 1784293020005, "status": "success", "tasks": [ { "id": "0mroxztkj-izqz7v0ufn", "start": 1784293020019, "status": "success", "end": 1784293020027, "result": { "merge": false, "size": 0 }, "message": "clean-vm" }, { "id": "0mroxztz1-v8ycdmtgo9k", "start": 1784293020541, "status": "success", "end": 1784293036537, "result": "20683621-7819-7661-91a2-93c377a7345a", "message": "snapshot" }, { "id": "0mroy06bf-9frdqsgnpym", "start": 1784293036539, "status": "success", "tasks": [ { "id": "0mroy0aun-bscsuoyzrpu", "start": 1784293042415, "status": "success", "tasks": [ { "id": "0mroy3r14-2sk7dgyqrbl", "start": 1784293203352, "status": "success", "end": 1784293207572, "message": "target snapshot" } ], "end": 1784293207573, "result": { "size": 9254731776 }, "message": "transfer" } ], "end": 1784293207664, "message": "export", "data": { "id": "a729e916-4cd8-2208-7dce-329e6b4af892", "isFull": true, "name_label": "xxxxx", "type": "SR" } }, { "id": "0mroy06bg-eyd2s4tidgg", "start": 1784293036540, "status": "success", "end": 1784293207664, "message": "export", "data": { "id": "b0b77301-4625-a13b-7022-9512f927944a", "isFull": true, "name_label": "xxxxxx", "type": "SR" } }, { "id": "0mroy06bh-ra3dxpusxr8", "start": 1784293036541, "status": "success", "end": 1784293207664, "message": "export", "data": { "id": "7054c407-d620-2c9f-5810-1e192a04ffe2", "isFull": true, "name_label": "xxxxxxxxx", "type": "SR" } }, { "id": "0mroy06bi-tdyzypsg58", "start": 1784293036542, "status": "success", "end": 1784293207664, "message": "export", "data": { "id": "621c9b87-4f58-987b-2c07-e8dee67da73a", "isFull": true, "name_label": "xxxxxxxxxx", "type": "SR" } }, { "id": "0mroy06be-u3p9nky3uwd", "start": 1784293036538, "status": "success", "tasks": [ { "id": "0mroy0aus-ax44kkpim1", "start": 1784293042420, "status": "success", "end": 1784293200916, "result": { "size": 9257013760 }, "message": "transfer" }, { "id": "0mroy434q-md07n6vujw", "start": 1784293219034, "status": "success", "end": 1784293219099, "result": { "merge": false, "size": 0 }, "message": "clean-vm" } ], "end": 1784293219102, "message": "export", "data": { "id": "c1fdab1d-5535-42e4-b282-1a0282df1081", "isFull": true, "type": "remote" } } ], "infos": [ { "message": "Transfer data using NBD" }, { "message": "will delete snapshot data" }, { "data": { "vdiRef": "OpaqueRef:080d2018-c2a3-aa6f-89a1-b3eaf72c3de5" }, "message": "Snapshot data has been deleted" } ], "end": 1784293219102, "message": "backup VM", "data": { "id": "d771731a-f132-7365-be50-71f19424f96e", "type": "VM", "name_label": "TESTREPL", "progress": 0 } } ], "end": 1784293219104, "infos": [ { "data": { "vms": [ "d771731a-f132-7365-be50-71f19424f96e" ] }, "message": "vms" } ] } { "data": { "mode": "delta", "reportWhen": "always", "backupReportTpl": "mjml" }, "id": "1784293990343", "jobId": "10d0331c-694e-4681-8860-33fef3790552", "jobName": "TESTCRANDBK", "message": "backup", "scheduleId": "bc7b29ce-25b2-4c66-9186-b1d4c314b979", "start": 1784293990343, "status": "success", "tasks": [ { "id": "0mroykonr-nktgebhtb4k", "start": 1784293993431, "status": "success", "tasks": [ { "id": "0mroykoo5-171n48gwq3r", "start": 1784293993445, "status": "success", "end": 1784293993493, "result": { "merge": false, "size": 0 }, "message": "clean-vm" }, { "id": "0mroykp31-4r5wrf9blru", "start": 1784293993981, "status": "success", "end": 1784294007573, "result": "9ff54ec5-0247-4692-945b-c183206ae6dd", "message": "snapshot" }, { "id": "0mroykzkm-ykzk53um8l", "start": 1784294007574, "status": "success", "tasks": [ { "id": "0mroyl3qn-vzompxsw79o", "start": 1784294012975, "status": "success", "end": 1784294018591, "result": { "size": 396481024 }, "message": "transfer" }, { "id": "0mroyljgo-nlch68rkbil", "start": 1784294033352, "status": "success", "end": 1784294033444, "result": { "merge": false, "size": 0 }, "message": "clean-vm" } ], "end": 1784294033446, "message": "export", "data": { "id": "c1fdab1d-5535-42e4-b282-1a0282df1081", "isFull": false, "type": "remote" } } ], "warnings": [ { "message": "the writer AggregatedIncrementalXapiWriter has failed the step writer.checkBaseVdis() with error Cannot read properties of undefined (reading 'get'). It won't be used anymore in this job execution." } ], "infos": [ { "message": "Transfer data using NBD" }, { "message": "will delete snapshot data" }, { "data": { "vdiRef": "OpaqueRef:77605638-5e58-4a10-c2de-bc6e77f1ad61" }, "message": "Snapshot data has been deleted" } ], "end": 1784294033447, "message": "backup VM", "data": { "id": "d771731a-f132-7365-be50-71f19424f96e", "type": "VM", "name_label": "TESTREPL", "progress": 0 } } ], "end": 1784294033449, "infos": [ { "data": { "vms": [ "d771731a-f132-7365-be50-71f19424f96e" ] }, "message": "vms" } ] } { "data": { "mode": "delta", "reportWhen": "always", "backupReportTpl": "mjml" }, "id": "1784295416670", "jobId": "10d0331c-694e-4681-8860-33fef3790552", "jobName": "TESTCRANDBK", "message": "backup", "scheduleId": "bc7b29ce-25b2-4c66-9186-b1d4c314b979", "start": 1784295416670, "status": "success", "tasks": [ { "id": "0mrozf8yr-lix8jxbm6pd", "start": 1784295419428, "status": "success", "tasks": [ { "id": "0mrozf8zg-zddbxm901mc", "start": 1784295419452, "status": "success", "end": 1784295419537, "result": { "merge": false, "size": 0 }, "message": "clean-vm" }, { "id": "0mrozf9dv-7nj082i92kp", "start": 1784295419971, "status": "success", "end": 1784295426890, "result": "18312e82-adb6-2dc5-b13e-2fd9a4b2bf77", "message": "snapshot" }, { "id": "0mrozfeq3-w3y5xrwtqse", "start": 1784295426891, "status": "success", "tasks": [ { "id": "0mrozfrvy-4g1gefr14hx", "start": 1784295443950, "status": "success", "end": 1784295445177, "result": { "size": 92319744 }, "message": "transfer" }, { "id": "0mrozfw5f-mx0xt5f7wjm", "start": 1784295449475, "status": "success", "end": 1784295449563, "result": { "merge": false, "size": 0 }, "message": "clean-vm" } ], "end": 1784295449565, "message": "export", "data": { "id": "c1fdab1d-5535-42e4-b282-1a0282df1081", "isFull": false, "type": "remote" } } ], "warnings": [ { "message": "the writer AggregatedIncrementalXapiWriter has failed the step writer.checkBaseVdis() with error Cannot read properties of undefined (reading 'get'). It won't be used anymore in this job execution." } ], "infos": [ { "message": "Transfer data using NBD" }, { "message": "will delete snapshot data" }, { "data": { "vdiRef": "OpaqueRef:6a833d28-2d2c-5fe6-858b-02d2fd41b919" }, "message": "Snapshot data has been deleted" } ], "end": 1784295449566, "message": "backup VM", "data": { "id": "d771731a-f132-7365-be50-71f19424f96e", "type": "VM", "name_label": "TESTREPL", "progress": 0 } } ], "end": 1784295449567, "infos": [ { "data": { "vms": [ "d771731a-f132-7365-be50-71f19424f96e" ] }, "message": "vms" } ] } Hope it helps

@pierrebrunet Hello! I've checked B2 logs and found some errors like you had foreseen. I had a look and this kind of 500 INTERNAL ERROR several times on other jobs that seem ok. How many retries does XO attempt to send the part when this happens? I'll do another run that includes only a few large VMs. BTW, is there a way to interrupt the job withou restarting XO ? REST.PUT.PART Weekly/xo-vm-backups/60b4d2a7-3f91-f0f9-b0a0-f834df3ff9ee/20260705T070618Z.xva "PUT /zzzzzkly/xo-vm-backups/60b4d2a7-3f91-f0f9-b0a0-f834df3ff9ee/20260705T070618Z.xva?partNumber=3954&uploadId=4_ze092693d1b65962e9fe6051b_f25969add7e42e384_d20260713_m140016_c003_v0312040_t0013_u01783951216751&x-id=UploadPart HTTP/1.1" 500 INTERNAL_ERROR 145 - 3762 3762 "-" "aws-sdk-js/3.1065.0 ua/2.1 os/linux#5.15.0-185-generic lang/js md/nodejs#24.18.0 api/s3#3.1065.0 m/N,a,c,E,e xen-orchestra-fs-4.9.2" - - - TLS_AES_256_GCM_SHA384 AuthHeader s3.eu-central-003.backblazeb2.com TLSv1.3 - -