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A colleague of mine accidentally deleted ldap transaction log files (from /var/lib/ldap) on our ldap 2.4 server running on centos. Now the slapd deamon won't start, when running it with debug flag here'e what is says:

file id2entry.bdb has LSN 754/2932421, past end of log at 1/660
sept. 11 12:40:14 centos7.ent.univ slapd[4917]: bdb(dc=uit,dc=ac,dc=ma): BDB2507 Commonly caused by moving a database from one database environment
sept. 11 12:40:14 centos7.ent.univ slapd[4917]: bdb(dc=uit,dc=ac,dc=ma): BDB2508 to another without clearing the database LSNs, or by removing all of
sept. 11 12:40:14 centos7.ent.univ slapd[4917]: bdb(dc=uit,dc=ac,dc=ma): BDB2509 the log files from a database environment

I attempted running the db_recover utility, it says recovery was successfull, but slapd won't start yet, same error.

Knowing for sure that the deletion of the log files is the culprit, and not having any backup files, is there any way to recover the database without the log files ?

2 Answers 2

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After several hours of trial an failure, here's what did it:

  1. Backup /var/lib/ldap and /etc/openldap

tar -czf ldap.bak.gzip /var/lib/ldap /etc/openldap

  1. Create a dump of the bdb files in /var/lib/ldap

db_dump -f file.dump file.bdb

  1. delete the bdb files then build them again using db_load (note down all the files if you delete them at once, or do it one by one)

rm -f file.bdb

db_load -f file.dump file.bdb

If you run into an error when running db_dump, run:

db_recover -h /var/lib/ldap

once you've built all the bdb files from dump files, make sure they're owned by the right user:

chown ldap:ldap /var/lib/ldap/*

Try to start the ldap deamon:

service slapd start

You might try to run another db_recover if it still won't start, but if all the bdb files were rebuilt successfully and have the right permissions, the deamon should start. At this point backup all your data to an ldif file:

slapcat > ldap.bak.ldif

Using an LDAP client, try manipulating data (add, edit, delete operations) if all is OK then good for you, if not, reinstall your LDAP server and restore the data using the ldif backup you made.

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  • What could you do if in the same scenario, the same errors are shown when trying to db_dump?
    – runr
    Jan 28, 2020 at 16:00
  • Can you share the error message received ?
    – Assil
    Feb 5, 2020 at 12:18
  • Exactly the same as in our original post (bdb2507, bdb2508 ....)
    – runr
    Feb 5, 2020 at 22:22
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@Assil, I saved a lot of time thanks to you

My simple additions:

  1. Dump all bdb files
mkdir /tmp/slapd-dump
cd /var/lib/ldap
find -type f -name "*.bdb" -exec db_dump -f /tmp/slapd-dump/{} {} \
  1. Restore from dump
cd /tmp/slapd-dump
find -type f -name "*.bdb" -exec db_load -f {} /var/lib/ldap/{} \;
cd /var/lib/ldap
  1. Refresh log files
rm -rf log.*
db_recover
  1. Manual start slapd
sudo -u ldap slapd
  1. Kill slapd

  2. Start slapd as service

For normal clean old log files do:

db_archive -d -h /var/lib/ldap/
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  • Glad I cloud help, great additions! saves even more time :)
    – Assil
    Dec 16, 2020 at 17:42
  • I think you're missing a semicolon in step 1 Dec 16, 2020 at 23:49

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