Database Backup freeze at wp_posts

I’m encountering a strange issue: when I try to back up the entire database, everything runs smoothly until it reaches the wp_posts table. At that point, the process times out and never completes, no matter how long I let it run.

The log.txt file shows the following:

0000.000 (0) Opened log file at time: Fri, 10 Oct 2025 09:00:25 +0000 on https://xxx.yyy.zzz.domain
0000.001 (0) UpdraftPlus WordPress backup plugin (https://updraftplus.com): 1.25.8 WP: 6.8.3 PHP: 8.3.19 (fpm-fcgi, Linux sh20212 4.18.0-553.75.1.el8_10.x86_64 #1 SMP Mon Sep 15 08:42:43 EDT 2025 x86_64) MySQL: 10.6.19-MariaDB (max packet size=64000000) WPLANG: de_DE Server: Apache safe_mode: 0 max_execution_time: 900 memory_limit: 256M (used: 145.4M | 148M) multisite: N openssl: OpenSSL 1.1.1w  11 Sep 2023 mcrypt: Y LANG:  WP Proxy: disabled ZipArchive::addFile: Y
0000.002 (0) Free space on disk containing Updraft's temporary directory: 780022.7 MB
0000.013 (0) Tasks: Backup files: 0 (schedule: monthly) Backup DB: 1 (schedule: daily)
0000.015 (0) Requesting semaphore lock (d) (apparently not via scheduler)
0000.016 (0) Semaphore (d, wp_options) was stuck, set lock time to 2025-10-10 09:00:25
0000.017 (0) Semaphore (d, wp_options) reset to 1
0000.017 (0) Set semaphore last lock (d) time to 2025-10-10 09:00:25
0000.017 (0) Semaphore lock (d) complete
0000.019 (0) Backup run: resumption=0, nonce=95ad5c738db9, file_nonce=95ad5c738db9 begun at=1760086825 (0s ago), job type=backup
0000.020 (0) Scheduling a resumption (1) after 300 seconds (1760087125) in case this run gets aborted
0000.038 (0) This backup run is not intended for files - skipping
0000.039 (0) Beginning creation of database dump (WordPress DB)
0000.040 (0) SQL compatibility mode is: ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
0000.040 (0) Testing potential mysqldump binary: /usr/bin/mysqldump
0000.060 (0) Output: /*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;\n/*!40103 SET TIME_ZONE='+00:00' */;\n/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;\n/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;\n/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;\n/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;\nDROP TABLE IF EXISTS wp_options;\n/*!40101 SET @saved_cs_client     = @@character_set_client */;\n/*!40101 SET character_set_client = utf8 */;\nCRE (truncated - 1443 bytes total)
0000.061 (0) Working binary mysqldump found: /usr/bin/mysqldump
0000.071 (0) Table wp_options: Total expected rows (approximate): 2537
0000.163 (0) Table wp_options: Rows added in this batch (next record: 70880): 2521 (uncompressed bytes in this segment=2688352) in 0.10 seconds
0000.166 (0) Table wp_options: finishing file(s) (2, 394.8 KB)
0000.169 (0) Table wp_users: Total expected rows (via COUNT): 5
0000.169 (0) Table is relatively small; fetch_rows will thus be: 20 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.170 (0) Table wp_users: Rows added in this batch (next record: 5): 5 (uncompressed bytes in this segment=1811) in 0.00 seconds
0000.171 (0) Table wp_users: finishing file(s) (2, 0.9 KB)
0000.174 (0) Table wp_usermeta: Total expected rows (via COUNT): 241
0000.175 (0) Table is relatively small; fetch_rows will thus be: 250 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.178 (0) Table wp_usermeta: Rows added in this batch (next record: 696): 241 (uncompressed bytes in this segment=27118) in 0.01 seconds
0000.180 (0) Table wp_usermeta: finishing file(s) (2, 6.6 KB)
0000.183 (0) Table wp_actionscheduler_actions: Total expected rows (via COUNT): 701
0000.193 (0) Table wp_actionscheduler_actions: Rows added in this batch (next record: 4240): 701 (uncompressed bytes in this segment=256055) in 0.01 seconds
0000.196 (0) Table wp_actionscheduler_actions: finishing file(s) (2, 14.4 KB)
0000.198 (0) Table wp_actionscheduler_claims: Total expected rows (via COUNT): 0
0000.199 (0) Table wp_actionscheduler_claims: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=625) in 0.00 seconds
0000.201 (0) Table wp_actionscheduler_claims: finishing file(s) (2, 0.4 KB)
0000.203 (0) Table wp_actionscheduler_groups: Total expected rows (via COUNT): 11
0000.203 (0) Table is relatively small; fetch_rows will thus be: 20 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.204 (0) Table wp_actionscheduler_groups: Rows added in this batch (next record: 11): 11 (uncompressed bytes in this segment=942) in 0.00 seconds
0000.206 (0) Table wp_actionscheduler_groups: finishing file(s) (2, 0.5 KB)
0000.208 (0) Table wp_actionscheduler_logs: Total expected rows (approximate): 2071
0000.218 (0) Table wp_actionscheduler_logs: Rows added in this batch (next record: 12634): 2071 (uncompressed bytes in this segment=239849) in 0.01 seconds
0000.220 (0) Table wp_actionscheduler_logs: finishing file(s) (2, 16.5 KB)
0000.223 (0) Table wp_commentmeta: Total expected rows (via COUNT): 0
0000.224 (0) Table wp_commentmeta: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=630) in 0.00 seconds
0000.225 (0) Table wp_commentmeta: finishing file(s) (2, 0.4 KB)
0000.228 (0) Table wp_comments: Total expected rows (via COUNT): 0
0000.228 (0) Table wp_comments: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=1509) in 0.00 seconds
0000.230 (0) Table wp_comments: finishing file(s) (2, 0.5 KB)
0000.232 (0) Table wp_e_notes: Total expected rows (via COUNT): 0
0000.233 (0) Table wp_e_notes: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=1885) in 0.00 seconds
0000.235 (0) Table wp_e_notes: finishing file(s) (2, 0.7 KB)
0000.237 (0) Table wp_e_notes_users_relations: Total expected rows (via COUNT): 0
0000.237 (0) Table wp_e_notes_users_relations: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=852) in 0.00 seconds
0000.239 (0) Table wp_e_notes_users_relations: finishing file(s) (2, 0.4 KB)
0000.241 (0) Table wp_links: Total expected rows (via COUNT): 0
0000.241 (0) Table wp_links: Rows added in this batch (next record: -1): 0 (uncompressed bytes in this segment=1023) in 0.00 seconds
0000.243 (0) Table wp_links: finishing file(s) (2, 0.5 KB)
0000.245 (0) Table wp_p14mz_itemmeta: Total expected rows (via COUNT): 4
0000.246 (0) Table is relatively small; fetch_rows will thus be: 20 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.246 (0) Table wp_p14mz_itemmeta: Rows added in this batch (next record: 5): 4 (uncompressed bytes in this segment=794) in 0.00 seconds
0000.248 (0) Table wp_p14mz_itemmeta: finishing file(s) (2, 0.5 KB)
0000.250 (0) Table wp_p14mz_items: Total expected rows (via COUNT): 62
0000.251 (0) Table is relatively small; fetch_rows will thus be: 100 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.252 (0) Table wp_p14mz_items: Rows added in this batch (next record: 101): 62 (uncompressed bytes in this segment=7436) in 0.00 seconds
0000.253 (0) Table wp_p14mz_items: finishing file(s) (2, 1.9 KB)
0000.255 (0) Table wp_p14mz_lists: Total expected rows (via COUNT): 33
0000.256 (0) Table is relatively small; fetch_rows will thus be: 50 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.257 (0) Table wp_p14mz_lists: Rows added in this batch (next record: 33): 33 (uncompressed bytes in this segment=43863) in 0.00 seconds
0000.259 (0) Table wp_p14mz_lists: finishing file(s) (2, 5.2 KB)
0000.261 (0) Table wp_p14mz_options: Total expected rows (via COUNT): 160
0000.262 (0) Table is relatively small; fetch_rows will thus be: 250 (allow_further_reductions=1, is_first_fetch=1, known_bigger_than_table=1)
0000.263 (0) Table wp_p14mz_options: Rows added in this batch (next record: 177): 160 (uncompressed bytes in this segment=15806) in 0.00 seconds
0000.265 (0) Table wp_p14mz_options: finishing file(s) (2, 3.6 KB)
0000.266 (0) Table wp_postmeta: Total expected rows (approximate): 56122
0002.987 (0) Table wp_postmeta: binary mysqldump finished (writes: 183, bytes 153786491, return code 0) in 2.72 seconds
0002.989 (0) Table wp_postmeta: finishing file(s) (1, 8416.4 KB)
0002.992 (0) Table wp_posts: Total expected rows (approximate): 7798

I’ve also tried disabling other plugins, but that didn’t make any difference.
Has anyone else experienced a similar problem? I can manually export/import the whole database with phpMyAdmin without any problems at all, so, i think it is not a database related issue…