SQL Server’s undocumented commands, options, and trace flags are sometimes carefully-guarded secrets. I’ve been a major secret-keeper of lots of these, having written/re-written a bunch of the undocumented DBCC commands. I’ve been assiduously avoiding writing this blog post for 14 years but now my hand has been forced. There’s one command in particular, DBCC WRITEPAGE, [...]
Paul S. Randal
In Recovery...
DBCC WRITEPAGE: an introduction
Posted on: February 5, 2013 11:45 am
SQL Server disaster-recovery poster now available
Posted on: February 1, 2013 10:46 am
A while back I wrote a comprehensive disaster-recovery flow chart in poster form for SQL Server Magazine, and I’m very happy that it’s now being made available! Edit 2/7/13: SQL Mag pulled the poster from their site again, but you can download it from here. The poster has links to a page with more explanations [...]
Corruption demo databases and scripts
Posted on: January 8, 2013 12:29 pm
I originally blogged a series of corruption demos and associated databases back in 2008, for use with SQL Server 2005 and 2008. Since then the releases have changed which databases and corruptions work and I’ve had to rework some of the databases for you. This is an update that takes into account SQL Server 2008R2 [...]
Importance of how often you take full backups
Posted on: December 21, 2012 11:39 am
A couple of weeks ago I kicked off a survey asking how often you perform full backups of your databases. Here are the results: The ‘Other’ values are: 20 x ‘Daily for small dbs, weekly (with daily diff) for large dbs.’ 16 x ‘Depends. Some daily, some weekly.’ 5 x ‘Daily on small, weekly on [...]
Importance of where you store your backups
Posted on: December 21, 2012 6:52 am
A couple of weeks ago I kicked off a survey about where you store your backups. Here are the results: The’Other’ responses are: 8 x ‘Stored on same SAN, different LUN as databases, with off-site copies.’ 6 x ‘Copy 1 stored on same SAN (1-2 days) for quick restore in non-physical disaster. Copy 2 stored [...]
When the going gets tough, the tough hide under the table
Posted on: October 29, 2012 11:35 am
That's a quote from one of my favorite comedy shows, Blackadder. With Hurricane Sandy bearing down on the North East Coast of the US today, whether you're in its path or not, it's a good time to consider what your reaction will be when faced with a disaster that affects the data you're responsible for. [...]
Multiple log files and why they’re bad
Posted on: September 24, 2012 3:48 pm
About a month ago I kicked off a survey with some code to run to figure out how many log files your databases have (see here). There are all kinds of misconceptions about transaction logs and how to configure them (and how they work) and I'm amazed at the misinformation I continue to see published. For [...]
Using fn_dblog, fn_dump_dblog, and restoring with STOPBEFOREMARK to an LSN
Posted on: May 17, 2012 3:05 am
I’ve blogged a bunch about using the undocumented fn_dblog function I helped write (and I’ve got a lot more to come :-) but here’s one I haven’t mentioned on my blog before: fn_dump_dblog (although I have talked about it at conferences last year). Here’s a scenario: someone dropped a table and you want to find [...]
SQL Server Magazine: feature article on using database repair
Posted on: August 25, 2011 11:29 am
The September SQL Server Magazine articles are now available on the web and include my latest feature article on Using Database Repair for Disaster Recovery. It includes a detailed walk-through of a disaster scenario where all backups include the corruption – showing you how to run repair and then try to recover some of the [...]
TechNet Magazine article: data protection and the corporate jigsaw puzzle
Posted on: April 6, 2011 11:27 am
My latest feature article for TechNet Magazine has just been published in the April edition. It focuses on planning an HA/DR strategy within the confines of a larger corporate IT strategy, from multiple perspectives but really focusing on the IT manager role and how to interact both up (to business managers) and down (to DBAs). [...]
Human nature is a significant hurdle to successful disaster recovery
Posted on: March 23, 2011 12:10 pm
A few weeks ago I kicked off a survey about disaster recovery testing and how the plan copes with human factors. You can see the original survey here. This Dilbert cartoon is a pretty accurate portrayal of most clients' disaster recovery plans when I first start working with them: http://dilbert.com/strips/comic/2000-08-15/. Here are the survey results: [...]
Surveys: DR plan testing and considering human nature
Posted on: March 11, 2011 10:14 am
The recent earthquake in New Zealand and this morning's devastating earthquake and subsequent tsunami in Japan set off a lot of discussion on twitter about DR planning and testing. I wrote a blog post on our SQL Server Magazine blog this morning asking people to think about their testing – see here. I'm conducting two [...]
Disaster recovery 101: fixing metadata corruption without a backup
Posted on: March 10, 2011 8:11 am
Yesterday on the MVP newsgroup someone was asking how to fix some metadata corruption when their backups all had the corruption in too. There are two options: export everything out to a new database or roll up your sleeves and manually fix the system tables. Although some people may think this is scary and dangerous [...]
Updated database size survey results
Posted on: February 22, 2011 1:22 pm
Last week I kicked off a survey about the size of the largest single SQL Server database in your company – see here for the survey. I was interested to see how the distribution has changed since I did the same survey a few years ago. 2011 results: 2009 results: Very interesting! As [...]
Unbelievable tale of disaster and recovery
Posted on: February 16, 2011 8:18 am
A few days ago one of my new blog readers (a pretty smart cookie, as you'll see) sent me a tale of database catastrophe and an excellent recovery that I’d like to share with you. The story’s been made anonymous and is published with full permission of the author (highlights in bold are mine). Hey [...]
Disaster recovery 101: hack-attach a damaged database
Posted on: June 18, 2010 12:11 pm
As a follow-up to my previous post Disaster recovery 101: backing up the tail of the log, I want to describe how to re-attach a damaged database if someone's detached it accidentally while performing disaster recovery. A couple of years ago I blogged a detailed post on Creating, detaching, re-attaching, and fixing a suspect database but now [...]
Disaster recovery 101: backing up the tail of the log
Posted on: June 18, 2010 9:21 am
One of the first things you should always check when a database has been damaged and you're going to perform a restore operation is whether you need to back up the tail of the log. The tail of the log contains the transaction log that's been generated since the most recent log backup was taken. If [...]
Whitepaper on high-availability architectures published
Posted on: June 4, 2010 11:00 am
The 20-page whitepaper I wrote this Spring for the SQL team has just been published. This whitepaper is titled Proven SQL Server Architectures for High Availability and Disaster Recovery and ties in with the longer whitepaper I wrote last year on High Availability with SQL Server 2008 (see here). This new whitepaper describes the five [...]
A SQL Server DBA myth a day: (30/30) backup myths
Posted on: April 30, 2010 9:19 am
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions blog posts collected together when you join our Insider list, plus my online Myths and Misconceptions training course on Pluralsight.) The month is finally over so time for the grand [...]
Important things for DBAs to consider
Posted on: April 12, 2010 4:31 pm
(Look in the Misconceptions blog category for the rest of the month’s posts and check out the 60-page PDF with all the myths and misconceptions blog posts collected together when you join our Insider list, plus my online Myths and Misconceptions training course on Pluralsight.) Over the last month or so I've found myself handing [...]
Sample corrupt databases to play with
Posted on: February 26, 2010 12:02 pm
The very worst piece of advice I ever saw on the Internet was in response to someone asking on a SQL newsgroup ‘how can I create a corrupt database?’. The first response was: When I want to corrupt a database to play with, I go into the data center, find a hard-drive and flick the [...]
TechNet Magazine: feature article on recovering from disasters using backups
Posted on: November 5, 2009 8:36 am
The November 2009 edition of TechNet Magazine is up on the web and contains my latest feature article, the second in a 3-part series on backups/restores/repairs. In this article I explain all about using the RESTORE command. Not much point having backups if you don't know how to use them! Topics include: The four phases [...]
Importance of having a good disaster recovery plan
Posted on: September 15, 2009 11:17 am
A few weeks ago I kicked off a survey asking what kind of disaster recovery guide/run-book/plan (I'll just call it a plan from now on) you have (see here for the survey). Here are the results as of 9/15/09: Out of all these answers, IMHO the last answer is the only acceptable one for [...]
Survey: what kind of disaster recovery guide do you have?
Posted on: August 26, 2009 1:50 pm
In this survey I'd like to find out what kind of disaster recovery guide/run-book/plan you have, if any. When a disaster occurs, do you just wing-it, or is there something written-down that was worked out in advance to help you along the way. I'll report on the results in a couple of weeks. *Please* no comments [...]
Importance of defining and measuring SLAs
Posted on: May 30, 2009 4:00 pm
In last week's survey I asked you two things, as a precursor to a whitepaper I'm writing for Microsoft The first question was what is your maximum allowable downtime SLA (either for 24×7 operation or not). See here for the survey. Here are the results as of 5/30/09. The Other values were all about not having [...]
Weekly survey: maximum allowable downtime – target and actual
Posted on: May 25, 2009 1:58 pm
This week's survey is inspired by this morning's Kimberly+Paul hot-tub conversation around data-dependent routing vs. network load balancing, which then turned to SLAs. Yes, we lead an exciting life . This survey is a *four*-parter. Part 1 is for each of your databases, which survey option is closest to your target maximum allowable downtime SLA (Service-Level [...]
Importance of testing your disaster recovery plan
Posted on: May 25, 2009 1:00 pm
In last week’s survey I asked whether you’re ever tested your disaster recovery plan, and if so, what happened? (See here for the survey). Here are the results as of 5/25/09: The ‘other’ responses are: 2 x “restored to test env regularly. don’t know if sla would be met.” 2 x “test it regularly, most [...]
Weekly survey: have you ever tested your disaster recovery plan?
Posted on: May 17, 2009 5:38 pm
This week's survey is inspired from many stories I saw on the forums and Twitter this week – mostly bad, one good (someone I'm following is spending the weekend testing their disaster recovery plan – cool!). I'd like to know whether you're ever tested your disaster recovery plan, and if so, what happened? I'll report [...]
Misconceptions around database repair
Posted on: May 15, 2009 5:02 pm
This week's been a busy one on the forums and Twitter, with lots of interesting problems people are hitting. One of the things I've noticed is that there are lot's of misconceptions about running repair, so to round out Friday I'm going to run through a list of them for you. Here are the misconceptions, [...]
A sad tale of mis-steps and corruption (from today)
Posted on: May 12, 2009 8:36 pm
This is a true story, and unfolded over the last few days. It's deliberately written this way, I'm not trying to be patronizing – just illustrating the mistakes people can make if they don't know what not to do. Once upon a time (well, a few days ago), there was a security person who had access [...]
How to get all the corruption messages from CHECKDB
Posted on: May 12, 2009 4:56 pm
Hopefully all of you reading my blog already know to use the WITH ALL_ERRORMSGS option whenever you run DBCC CHECKDB (which is now the default in 2005 SP3, haven't checked if it made it into 2008 SP1). If you're doing some quick analysis of the results to see, for example, whether it's just nonclustered indexes [...]
Importance of having the right backups
Posted on: May 2, 2009 6:32 am
Last week's survey was on what kind of backups you take, along with the recovery model used (see here for the survey). Here are the results as of 5/2/2009. The 'other' responses were combinations of the other answers. This survey is a bit of a pre-cursor to my article on Understanding SQL Server Backups [...]
Weekly survey: what kind of backups do you take?
Posted on: April 27, 2009 2:44 am
In this week's survey I'm interested in what kind of backups you take, and also what recovery model you mostly use. If you have multiple database with different strategies, by all means respond multiple times. The more responses the better! I'll report on the survey results some time over the weekend of 5/2/2009. A couple [...]
Physical database layout vs. database size
Posted on: April 27, 2009 12:21 am
A couple of weeks ago I kicked off the latest survey, on what the physical layout of your databases are and why you have them that way (see here for the survey). I let the survey run for a while to get a good sampling, and I wasn't disappointed, with over 1000 responses! Here are [...]
Weekly survey: does size really matter – or is it what you do with it?
Posted on: April 10, 2009 3:05 pm
This week's survey is a little more complicated. I'm interested in the physical layout of your databases. I've got four surveys, for a variety of database sizes. Please vote multiple times in each survey, as you see fit – and by all means forward this link to your friends/clients/etc or re-blog/tweet it. I'm going to report [...]
Is running repair on msdb safe?
Posted on: March 25, 2009 9:02 am
Just saw this on a forum – running REPAIR_ALLOW_DATA_LOSS on msdb to cope with corruption. Yes, this will work but it's certainly not safe and something I'd only recommend as a last resort. Here's why: msdb stores your backup history and your Agent jobs. REPAIR_ALLOW_DATA_LOSS works by usually "delete what's broken and fix up all [...]
Importance of validating backups
Posted on: March 13, 2009 5:17 pm
Last week I kicked off the first weekly survey – on whether you validate your backups or not (see here for the survey). The results are very interesting (as of 3/13/09): As you can see, almost 25% of respondents never validate their backups! And a further 25% only validate them occasionally, with 30% doing some [...]
TechNet Radio interview on database corruption
Posted on: January 12, 2009 11:00 am
Well, we're back from vacation finally (only for 10 days and then off to India and Thailand for 3 weeks… phew) and I've got a bunch of blogs posts to catch up on. First up – I did an interview with TechNet Radio in mid-December where I talked about database corruption and things to do [...]
TechEd demo: nonclustered index corruption
Posted on: December 17, 2008 11:03 am
This blog post describes the demo "2 – NC Indexes" from my Corruption Survival Techniques conference session from various conferences in 2008. The links to the scripts and databases to use are in this blog post. Edit 6/4/2012: Be aware that in versions of SQL Server from 2008 onwards, you may only be able to [...]
TechEd: 80 minute video of Corruption Survival Techniques presentation
Posted on: December 5, 2008 6:14 am
For those of you who couldn't make it to a conference this year where I presented my Corruption Survival Techniques session, the folks at TechEd EMEA have just posted an 80 minute long video of the presentation I did in Barcelona in early November. It walks through I/O errors, what CHECKDB does, how it works, [...]
TechEd demo: corruptions fatal to DBCC CHECKDB
Posted on: November 30, 2008 5:37 pm
This blog post describes the demo “1 – Fatal Errors” from my Corruption Survival Techniques conference session from various conferences in 2008. The links to the scripts and databases to use are in this blog post. The aim of this demo is to show that sometimes a database is so corrupt that DBCC CHECKDB just [...]
Corruption survival techniques – useless?
Posted on: November 25, 2008 11:29 am
Now, I’m very thick-skinned and I know there are always some people in a conference session who don’t agree with everything I say (that’s human nature, and I’m totally cool with that) but this one I just couldn’t pass up mentioning here on the blog as I *utterly* disagree with the advice in that post, [...]
Conference corruption demo scripts and example corrupt databases
Posted on: November 24, 2008 11:27 am
This blog post explains the demo scripts and databases I've posted to cover all the Corruption Survival Techniques and DBCC CHECKDB sessions I've presented at conferences this year. There are two zip files you need to download: the example corrupt databases (36-MB zip) (and this one if you're on 2008) and the demo scripts. These [...]
Planning a backup strategy – where to start?
Posted on: October 26, 2008 11:13 am
It's been almost exactly a week since the last post – an unusually long time for me. Kimberly and I were teaching the first week of the inaugural Microsoft Certifed Masters SQL course last week in Redmond (a little intense at 8 hours of *teaching* per 10-hour day – so no energy for blogging afterwards). [...]
Reminder of why hardware redundancy is a good thing
Posted on: October 19, 2008 2:59 pm
One of our customers (and friends!) sent us this last week – a stark reminder why hardware redundancy is a good idea! The controller card in one of his servers literally blew up at 7.15am Tuesday morning. Although they didn't have redundant hardware, they were back online by 9am – pretty good going. Funnily [...]
Can the hack-the-suspect-database-into-the-server trick work for corrupt file headers?
Posted on: September 2, 2008 10:08 am
(Quickie post #3 while it's Kimberly's turn to lecture this morning – better pay attention now before I get into trouble) Gail asked a (paraphrased) question about the trick to hacking a detached suspect database into the server again – will it work for a detached database with multiple data files in the primary filegroup [...]
Better behavior with suspect databases in SQL Server 2008
Posted on: September 2, 2008 9:44 am
(Quickie post #1 while it’s Kimberly’s turn to lecture this morning…) I had a comment on my post dealing with suspect databases, saying that the 2008 behavior is much better. I hadn’t tried this so it was (really good) news to me. So, trying the same steps from that blog post on 2008 – everything’s [...]
Creating, detaching, re-attaching, and fixing a SUSPECT database
Posted on: August 29, 2008 7:55 pm
(Be sure to join our community to get our bi-weekly newsletter with exclusive content, demo videos, and other SQL Server goodies! Also check out our online training courses.) This is a post I’ve been trying to get to since I started blogging a couple of years ago: how to re-attach a detached SUSPECT database. This [...]
SQL Server 2008: How to rebuild the system databases?
Posted on: August 29, 2008 5:04 pm
When I started blogging, way back in 2006 :-), the third post I made on the old Storage Engine blog was about rebuilding the msdb database in 2005 (see here). This no longer works in 2008 (fellow MVP Tibor Karaszi explains why here), and in fact the information in Books Online about how to rebuild [...]
Should Microsoft provide a transaction log reader tool?
Posted on: August 26, 2008 12:21 am
Now this one’s sure to spark some controversy… I was checking my RSS feeds of the SQL blogs that I follow and noticed an interesting post on Kalen’s blog (the post is here). She’d been lambasted for suggesting in the weekly SQL Server Magazine newsletter that *Microsoft* shouldn’t provide a log reader tool and asked [...]
SQL Server 2008: Does my database contain Enterprise-only features?
Posted on: August 23, 2008 4:06 pm
Moving databases around is pretty common, as is moving databases between servers running different Editions of SQL Server, especially during a disaster recovery situation. You may not know this, but in SQL Server 2005, if you had partitioning anywhere in a database, you could only attach/restore that database using an Enterprise or Developer instance. I [...]
Search Engine Q&A #22: Can all page types be single-page restored?
Posted on: August 11, 2008 7:32 pm
I've had a few follow-ups on my two posts about boot page and file header page corruption – asking if its possible to do single-page restore operations for these pages. Let's try: CREATE DATABASE BootPageTest; GO – Single page restore is only possible using the FULL recovery model ALTER DATABASE BootPageTest SET RECOVERY FULL; GO [...]
How to tell if you have instant initialization enabled?
Posted on: August 11, 2008 7:10 pm
As you may already know, instant initialization is a way to prevent data (not log) file create and grow operations having to zero-initialize the new space before allowing it to be used. This can vastly speed up these operations as zero-initialization can take a *long* time for large files. This is especially useful in disaster [...]
Using the Dedicated Admin Connection to fix Msg 8992: corrupt system tables
Posted on: June 12, 2008 1:42 am
Today I presented my brand new session Surviving Corruption: From Detection to Recovery at TechEd. I had a lot of fun putting together the demos, presenting the session, and talking to people afterwards. During the session, I promised to blog each of the demos so that everyone can run through them – here's the first one. [...]
CHECKDB From Every Angle: Using DBCC PAGE to find what repair will delete
Posted on: June 9, 2008 3:54 pm
(I’m actually on-stage here at TechEd doing the DAT track pre-con with Kimberly – she’s on now until lunch so I’m catching up on forum problems…) Here’s a question that came up on of the SQLServerCentral.com corruption forums I monitor that I think is worth blogging about. To paraphrase: I have a bunch of corruptions in [...]
Do backups apply to just digital data? And how many backups should you have?
Posted on: May 18, 2008 1:41 am
So Seattle weather went from 50 degrees to 85 degrees overnight Friday and we all went from shivering to sweating! It's too hot to be sitting outside so we're both sitting inside getting a little work done. Well, I should really say 'work' as neither of us are actually doing anything productive for the business. Both of [...]
HA: Where do you start when choosing a high-availability solution?
Posted on: March 13, 2008 9:14 pm
It seems that today is going to be one of those days where I get lost in forums and blogging – I can live with that :-) One of the questions that came up on a forum today was about choosing an HA solution – based solely on the hardware that was running the database! [...]
Search Engine Q&A #17: Split a VLDB into filegroups or smaller databases for backups?
Posted on: March 13, 2008 5:41 pm
Here’s an interesting question that came in to our questions line (questions@SQLskills.com - no guarantee of an answer – I check it every so often): I have seen demonstrations where a large database being broken down into smaller ones using synonym names. I think it was used on a data warehouse and allowed smaller database backups [...]
Available for download: Our High-Availability hands-on labs and SQL Server 2008 JumpStart materials
Posted on: March 12, 2008 5:23 pm
A couple of weeks ago I blogged about the three tracks of the SQL Server 2008 JumpStart course that SQLskills.com taught internally for Microsoft and some MVPs – see here for details. Well, the content is now available to download! Note that this was based on CTP-5 (November 2007 CTP) and there have been *lots* [...]
CHECKDB From Every Angle: Example DBCC CHECKDB run-times
Posted on: February 12, 2008 8:35 pm
Almost a year ago to the day I asked a question on my old blog – how long does *your* CHECKDB take to run? Well, I had a bunch of replies but I never got around to posting the results. I was reminded of this recently so threw together some graphs of the results. I've [...]
Paul and Kimberly interview on RunAs Radio – What’s New in SQL Server 2008?
Posted on: December 12, 2007 6:07 pm
While we were in Barcelona we sat down with Richard Campbell and Greg Hughes from RunAs Radio to record a 1/2 hour interview on SQL Server 2008. We touch on a ton of different features (look at the number of Categories I’ve tagged this with!) and have a bunch of laughs along the way – [...]
Conference Questions Pot-Pourri #6: How to cope with losing the mirror AND the witness in a mirroring session?
Posted on: November 16, 2007 3:31 am
Here’s a question that came up yesterday in our chalk-talk on database mirroring at TechEd IT Forum that Kimberly and I talked about this morning (here in Barcelona). Q) I have a database mirroring session where the witness and mirror servers are in one physical location, and the principal server is in another. The mirroring session [...]
CHECKDB From Every Angle: Can CHECKDB repair everything?
Posted on: November 16, 2007 2:28 am
In my previous post on interpreting CHECKDB output, plus in my DBCC Internals session at TechEd IT Forum yesterday, I mentioned there are some things that CHECKDB can’t repair. In this post I want to go into a bit more detail – based on a post from my old Storage Engine blog. Before anyone takes [...]
CHECKDB From Every Angle: How long will CHECKDB take to run?
Posted on: November 15, 2007 4:22 am
This is a subject I posted about last year on my old blog but it came up at SQL Connections last week several times so I want to repost it for those who’ve just started following my blog. There’s only one time when you should be trying to work out how long a CHECKDB is [...]
CHECKDB From Every Angle: Tips and tricks for interpreting CHECKDB output
Posted on: November 14, 2007 7:07 am
Last week at SQL Connections someone said that CHECKDB’s output is ‘useless’. Given that I wrote CHECKDB for SQL Server 2005 I was only mildly offended :-) But there’s a lot of truth in that statement – the error messages from CHECKDB do tell you exactly what’s corrupt in the database but they’re not exactly [...]
BACKUP WITH COPY_ONLY – how to avoid breaking the backup chain
Posted on: October 15, 2007 9:37 pm
(I’ve heard from many of you that the Comments feature of my blog isn’t working. I know – there’s an issue with our blog engine that we’re fixing. My apologies – I’ll post a quick note when it’s fixed.) After posting last week about a BACKUP feature that I don’t like (WITH NO_LOG – see [...]
BACKUP LOG WITH NO_LOG – use, abuse, and undocumented trace flags to stop it
Posted on: October 12, 2007 5:09 pm
This has come up several times over the last few days, and is something that Kimberly and I discuss (and deplore) when we lecture – the use of BACKUP LOG WITH NO_LOG (or TRUNCATE_ONLY – they’re synonymous) to allow log truncation. How is it used? The common use is when the transaction log grows to [...]
SQL Server 2008: Performance boost for Database Mirroring
Posted on: October 11, 2007 12:06 am
As I mentioned in a previous post, one of the new features for database mirroring in SQL Server 2008 is log stream compression. There’s a good explanation of what this is (along with some example workloads and performance graphs) on the SQL Customer Advisory Team blog so I’m not going to duplicate all that here. Basically, the [...]
Search Engine Q&A #7: Restoring from a backup file containing multiple database backups
Posted on: October 10, 2007 1:35 am
This is another question that came up on the Disaster Recovery forum on MSDN. Paraphrasing – ‘ I have a backup file containing full backups for 45 databases. How can I restore them all using a script?’ The answer is pretty straightforward. Let’s create the situation described, using 3 databases for clarity rather than 45: [...]
How does daylight savings time affect disaster recovery?
Posted on: October 6, 2007 5:49 pm
It’s common knowledge that SQL Server copes with daylight savings time (DST) correctly so why should you care? Well, it’s not so common knowledge that at the end of DST when the clocks go back an hour (always at 02:00 in the U.S.), SQL Agent essentially pauses for an hour (in at least SS2000 onwards). This [...]
EMERGENCY-mode repair: the very, very last resort
Posted on: October 2, 2007 11:26 pm
(Be sure to join our community to get our bi-weekly newsletter with exclusive content, demo videos, and other SQL Server goodies! Also check out our online training courses.) This is a follow-on from two posts: Corruption: Last resorts that people try first… where I discussed the two worst things you can do (in my opinion) [...]
Search Engine Q&A #4: Using EMERGENCY mode to access a RECOVERY PENDING or SUSPECT database
Posted on: October 2, 2007 5:20 pm
By far the most common search engine query leading to the blog is about fixing a suspect or unrecovered database. The very best way to do this is to use your backups, and to have a backup strategy that allows you to recover in the smallest amount of time and with no data loss. But [...]
Corruption: Last resorts that people try first…
Posted on: September 15, 2007 12:29 am
These next few posts are based off part of my Secrets of Fast Detection and Recovery from Database Corruptions session from TechEd and various user groups around the world (Edit: see here for a video recording from TechEd 2008). In this post I want to describe the two worst things I think you can do [...]
Common bad advice around disaster recovery
Posted on: September 13, 2007 8:05 pm
Now that I have a little more time on my hands I’ve been jumping back into some of the online forums. Last summer I posted on a few bits of bad advice I’ve seen in the forums but yesterday I was stunned by some of the terrible advice I saw being given out. So, I’d [...]
Example 2000/2005 corrupt databases and some more info on backup, restore, page checksums and IO errors
Posted on: September 4, 2007 8:31 pm
This was originally posted as two posts on the SQL Server Storage Engine site. It was very popular so I’ve combined the two posts together and added a bunch more commentary – especially on page checksums and IO errors. You may also notice some color differences between the scripts from earlier in the year and today’s post [...]
