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• Backup
• DBCC CHECKDB Series
• On-Disk Structures
• Restore

• Example corrupt database to play with and some backup/restore things to try

  I've been asked several times over the last few weeks for an example corrupt database to play with, and for testing logic built around DBCC CHECKDB. The attached WinZip file contains a backup of a simple 2005 database called 'broken' (I can do a 2000 Read More... Posted Tuesday, April 17, 2007 10:22 AM by Paul Randal - MSFT | 10 Comments Filed under: DBCC, Disaster Recovery Attachment(s): broken.zip

• Oh no – my backup is corrupt too! Help!

  Funny how a bunch of people all seem to have the same problem at the same time. Maybe it’s just that people don’t want to talk about corruption until someone else does – it’s like a dark secret that once let out of the bag – everyone talks. The common Read More... Posted Monday, March 05, 2007 1:59 PM by Paul Randal - MSFT | 2 Comments Filed under: DBCC, Disaster Recovery, Backup, Restore

• CHECKDB (Part 8): Can repair fix everything?

  I was teaching at a Microsoft-internal class last week and there was a discussion on what corruptions can't be repaired using DBCC. At the same time, several threads popped up on forums and newsgroups with people hitting some of this unrepairable corruptions Read More... Posted Sunday, February 04, 2007 4:53 PM by Paul Randal - MSFT | 3 Comments Filed under: DBCC, Disaster Recovery, DBCC CHECKDB Series, On-Disk Structures

• CHECKDB (Part 7): How long will CHECKDB take to run?

  This is a question I see every so often and it cropped up again this morning so I'll use it as the subject for this week's blog post. There are several ways I could answer this: the unhelpful answer - I've got no idea. the almost-helpful answer - how Read More... Posted Wednesday, January 24, 2007 1:12 PM by Paul Randal - MSFT | 5 Comments Filed under: DBCC, Disaster Recovery, DBCC CHECKDB Series

• Fixing damaged pages using page restore or manual inserts

  Here's an interesting scenario that cropped up today. You have a database on a RAID array that failed and has zero'd out a page. How can you get the data back? There are two ways to do it, depending on the database recovery model and version of SQL Server Read More... Posted Thursday, January 18, 2007 12:02 AM by Paul Randal - MSFT | 8 Comments Filed under: DBCC, Disaster Recovery

• CHECKDB (Part 6): Consistency checking options for a VLDB

  (Yippee - just finished my certification dives and got my PADI Open Water certification - just in time for our dive trip to Indonesia in December :-) This is a question that comes up a lot - in fact 3 times this week already - most recently during a guest Read More... Posted Friday, October 20, 2006 3:57 AM by Paul Randal - MSFT | 9 Comments Filed under: DBCC, Disaster Recovery, DBCC CHECKDB Series

• Don't try this at home kids... (data recovery using DBCC PAGE)

  Time to cough up a real-life data recovery scenario to temporarily stop those people who badger me relentlessly for scenarios... We have a situation currently with a customer who managed to delete all their data during a SAN reconfig and then found out Read More... Posted Wednesday, August 09, 2006 8:41 PM by Paul Randal - MSFT | 5 Comments Filed under: DBCC, Disaster Recovery, On-Disk Structures

• Can't I ever get a guarantee?

  I've been sitting and thinking a lot about guarantees this morning while drinking coffee in the debilitating heat here (85 degrees at 11am) and things get more complicated the more I think about it, so time to stop and post some thoughts. Over the last Read More... Posted Sunday, July 23, 2006 7:19 PM by Paul Randal - MSFT | 3 Comments Filed under: DBCC, Disaster Recovery

• Ta da! Emergency mode repair

  Emergency mode repair? In a couple of previous posts I explained how the two worst things you could do to your database are rebuilding your transaction log and running REPAIR_ALLOW_DATA_LOSS . Well, in SQL Server 2005, we combined them into a new documented Read More... Posted Sunday, June 18, 2006 4:00 PM by Paul Randal - MSFT | 5 Comments Filed under: DBCC, Disaster Recovery

• Which part of 'REPAIR_ALLOW_DATA_LOSS' isn't clear?

  In my chalk/talk at TechEd yesterday, I asked the crowd "what's the purpose of repair?" One person got it right. The purpose is not to save data. Surprised? The purpose is to get the database back to a structurally and transactionally consistent state Read More... Posted Friday, June 16, 2006 2:57 AM by Paul Randal - MSFT | 8 Comments Filed under: DBCC, Disaster Recovery

• When should you rebuild the transaction log?

  10 points if you answered "don't be daft, never! " and minus several million is you answered anything else. Yes, if you have no backups and your hardware has corrupted your transaction log then you have no choice but to rebuild it, but this should never Read More... Posted Thursday, June 15, 2006 5:07 PM by Paul Randal - MSFT | 6 Comments Filed under: DBCC, Disaster Recovery

• How to use DBCC PAGE

  Yes, finally I come clean and tell all. It's an open secret that there's an undocumented DBCC command called DBCC PAGE that you can use to look at the contents of database pages. I've recommended in forum postings that people use it and Product Support Read More... Posted Saturday, June 10, 2006 7:14 PM by Paul Randal - MSFT | 9 Comments Filed under: DBCC, Disaster Recovery, On-Disk Structures

• Common bad advice around disaster recovery

  I've just been itching to post this one. I'm doing a chalk-talk (AKA cabana session, this year AKA Technical Learning Centre session) at TechEd next Wednesday (8.30am 6/14) called 'DBCC CHECKDB: Magic, Monsters, and Myths'. A lot of the material in this Read More... Posted Wednesday, June 07, 2006 8:01 PM by Paul Randal - MSFT | 17 Comments Filed under: DBCC, Disaster Recovery

• Repair vs Restore Dilemma

  For some reason The Clash's 'Should I Stay or Should I Go?' has been going round in my head today - 'Should I RE-pair or restore? Nah nah NA-na nana nah' - must be something to do with Redmond's good weather. Anyway, I get asked for help with this a lot Read More... Posted Wednesday, June 07, 2006 5:21 AM by Paul Randal - MSFT | 13 Comments Filed under: DBCC, Disaster Recovery