Re: [GENERAL] ERROR: unexpected chunk number 0 (expected 1) for toastvalue 76753264 in pg_toast_10920100

Hi Tom,

Thanks for attempting to replicate the issue.

Anyway, the bad news is I couldn't reproduce the problem then and I can't
now.  I don't know if it's a timing issue or if there's something critical
about configuration that I'm not duplicating.  Can you explain what sort
of platform you're testing on, and what nondefault configuration settings
you're using?

Further details about the environment that I can replicate on below:

- Non default postgresql.conf settings:

checkpoint_segments = 192

checkpoint_completion_target = 0.9

checkpoint_timeout = 5min

wal_keep_segments = 256

wal_writer_delay = 200ms

archive_mode = on

archive_command = 'rsync -e ssh -arv  /wal/pg_xlog/%f postgres@<removed hostname>:/wal/pg_xlog'

archive_timeout = 60

syslog_facility = 'LOCAL0'

log_statement = 'mod'

syslog_ident = 'postgres'

log_line_prefix = '%h %m  %p %c %u %a  %e '

log_timezone = 'GB'

track_activities = on

track_counts = on

datestyle = 'iso, mdy'

timezone = 'GB'

default_text_search_config = 'pg_catalog.english'

array_nulls = on

sql_inheritance = on

standard_conforming_strings = on

synchronize_seqscans = on

transform_null_equals = off

- Two node master/slave setup using streaming replication (without slots).

- CentOS 6.9 (2.6.32-696.el6.x86_64).

- PostgreSQL 9.4.10 on x86_64-unknown-linux-gnu, compiled by gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-17), 64-bit.

- 64GiB RAM.

- AMD Opteron(TM) Processor 6238.

- pg_default sat on 2 disk RAID-1 conifugration (ext3 filesystem).

- Custom tablespaces (where the errors occur) sat on 4 disk RAID-10 (ext3 filesystem).

- All disks are HP 600G SAS 6.0Gbps with P420(i) controllers and battery backed cache enabled.

Maybe you could give some info on :
- your ext3 mkfs and mount options (journal, barriers, etc)
- your controller setup (battery should be working good and cache mode set to write back)
- your disks setup (write cache should be disabled)
- you should check your syslogs/messages for any errors related to storage
- is your RAM ECC? Did you run any memtest?
- is your CPU overheating ?
- have you experienced any crashes/freezes ?

Please let me know if you require further info.

Best wishes,

Harry

-- 
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt