Errors after cloning OS to new disk under Hyper-V - Mailing list pgsql-general

Hello,

This is PostgreSQL v10.10 64Bit, running on Windows 10 64Bit.

One user, by himself, without asking for help, cloned his OS from one disk to Hyper-V disk. Old disk was not accessed,
OSwas shutdown while he is doing the cloning. He used some kind of tool that I do not know for that purpose. New server
isrunning under Hyper-V. 

Once he saw Hyper-V server is up and running he deleted old disk for good. Unfortunately, new system has more than
briefproblems. He has no backup of the database cluster or particular database(s) in it. 

I see in log following errors:
2020-07-16 12:28:17.598 +03 [3964] HATA (ERROR):  "pg_opclass_oid_index" indeksinde 0 bloğunda beklenmeyen boş sayfa
2020-07-16 12:28:17.598 +03 [3964] İPUCU:Lütfen onu REINDEX'leyin.
2020-07-16 12:29:02.065 +03 [2744] LOG:  istemciden veri alınamamıştır: unrecognized winsock error 10054
2020-07-16 12:29:17.699 +03 [3748] HATA (ERROR):  "pg_opclass_oid_index" indeksinde 0 bloğunda beklenmeyen boş sayfa
2020-07-16 12:29:17.699 +03 [3748] İPUCU:Lütfen onu REINDEX'leyin.
2020-07-16 12:30:17.805 +03 [1456] HATA (ERROR):  "pg_opclass_oid_index" indeksinde 0 bloğunda beklenmeyen boş sayfa
2020-07-16 12:30:17.805 +03 [1456] İPUCU:Lütfen onu REINDEX'leyin.
2020-07-16 12:30:47.363 +03 [7460] ÖLÜMCÜL (FATAL):  base/16394/2684 nesnesinin 0 bloğunda geçersiz sayfa
2020-07-16 12:31:04.009 +03 [1240] ÖLÜMCÜL (FATAL):  base/16394/2684 nesnesinin 0 bloğunda geçersiz sayfa
2020-07-16 12:31:11.261 +03 [2396] ÖLÜMCÜL (FATAL):  base/16394/2684 nesnesinin 0 bloğunda geçersiz sayfa

Basic translation to English is:
ERROR: "pg_opclass_oid_index" index 0 block unexpected empty page
HINT:Please REINDEX it.
LOG:  cannot read fata from client: unrecognized winsock error 10054
FATAL:  base/16394/2684 object 0 block invalid page

When I try to connect server on command line using psql I get same error:
PS C:\Program Files\PostgreSQL\10 - Kopya\bin> .\psql.exe -U postgres
psql: ÖLÜMCÜL (FATAL):  "pg_opclass_oid_index" indeksinde 0 bloğunda beklenmeyen boş sayfa
İPUCU:  Lütfen onu REINDEX'leyin.

PS C:\Program Files\PostgreSQL\10 - Kopya\bin> .\psql.exe -U postgres -h localhost
psql: ÖLÜMCÜL (FATAL):  "pg_opclass_oid_index" indeksinde 0 bloğunda beklenmeyen boş sayfa
İPUCU:  Lütfen onu REINDEX'leyin.

I am told that some databases in cluster can be accessed, not all. They are accessed from an application and not by
admintools. I do not know how many databases exists in the cluster or their names. 

I have tried to dump everything and that also failed:
PS C:\logs> & 'C:\Program Files\PostgreSQL\10 - Kopya\bin\pg_dumpall.exe' -f dump.bak -U postgres
pg_dump: [arşivleyici (db)] sorgu başarısız oldu: HATA (ERROR):  base/16394/2684 nesnesinin 0 bloğunda geçersiz sayfa
pg_dump: [arşivleyici (db)] sorgu şu idi: SELECT pg_catalog.set_config('search_path', '', false)
pg_dumpall: pg_dump "ZEntegre" veritabanında başarısız oldu, çıkılıyor

I wonder if there is anything that can be done here.

Thanks & Regards,
Ertan