IO is frozen for snapshot / IO is thawed

Question

IO is frozen for snapshot / IO is thawed

ht2k

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Points: 813
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November 23, 2004 at 3:09 pm

#109339

Following error message on SQL Server log.
(SQL Server 2000 SP3a on Windows 2003 ADV server 8 GB RAM)
Backups are not running at this time. Transaction backup runs every 2 hours but very low transactions (Activity on the server)
I have found following error messages in SQL Server Agent log files. How can I resolve it?
2004-11-22 05:13:04.71 spid89 Database USERDB3: IO is frozen for snapshot
2004-11-22 05:13:04.71 spid88 Database USERDB2: IO is frozen for snapshot
2004-11-22 05:13:04.71 spid92 Database model: IO is frozen for snapshot
2004-11-22 05:13:04.71 spid93 Database msdb: IO is frozen for snapshot
2004-11-22 05:13:04.71 spid94 Database USERDB1: IO is frozen for snapshot
2004-11-22 05:13:04.93 spid90 Database master: IO is frozen for snapshot
2004-11-22 05:13:06.51 spid88 Database USERDB2: IO is thawed
2004-11-22 05:13:06.51 spid89 Database USERDB3: IO is thawed
2004-11-22 05:13:06.51 spid93 Database msdb: IO is thawed
2004-11-22 05:13:06.51 spid92 Database model: IO is thawed
2004-11-22 05:13:06.51 spid94 Database USERDB1: IO is thawed
2004-11-22 05:13:06.51 spid90 Database master: IO is thawed
Thanks for your help in advance.

Viewing 13 posts - 1 through 12 (of 12 total)

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ccc24 Mr or Mrs. 500 Points: 503 More actions · Answer 1

We get that also when we EMC frame tools to create an SRDF to copy to our disaster site. Do you have an EMC frame for your data disk(s).

Pat Mong

ht2k SSC Eights! Points: 813 More actions · Answer 2

Unfortunately, We do not have EMC frame tools. Only one third party component that we run is veritas backup utility for tape back up every night.

ccc24 Mr or Mrs. 500 Points: 503 More actions · Answer 3

So your server uses internal disk? Does this happen every day? At the same timeframe? Are there any SQL jobs or scheduled tasks running then?

Pat Mong

ccc24 Mr or Mrs. 500 Points: 503 More actions · Answer 4

Also, you have almost a 2 minute stoppage of I/O. That's a LONG time.

Pat Mong

ht2k SSC Eights! Points: 813 More actions · Answer 5

It's usually between 5 and 6 AM. SQL Server backup jobs run between 8:00 pm to 9:00 pm. It takes less than 3 minutes for each backup to complete. Backups are on disk and nightly veritas pickups backup files and backups on tape.

Angela But Hall of Fame Points: 3848 More actions · Answer 6

These aren't error messages. They are messages generated by whatever third party backup tool you are using at a file level. I'm guessing you have a third party tool with a SQL Agent that allows it to backup your databases directly.

We get the exact same messages from our SAN while the snapshot backups take place. I still have nativel SQL backups running though. While your databases are 'frozen' they are essentially offline and no users will be able to connect.

In your case I think your Veritas backup is actually taking a snapshot backup of your databases, rather than only backing up your SQL backup files.

htrivedi_2000@yahoo.com SSC Eights! Points: 839 More actions · Answer 7

Thanks for your responses. We do run Veritas backup component. I will check the schedule and view history to find out what time it hits the server in question for tape backup?

Thanks

Martin Rutten SSC Rookie Points: 49 More actions · Answer 8

I had the same problem on our W2K3 machine. Finally I figured out what caused the problem: ntbackup. This program has a commandline switch called /SNAP. Whenever you run a ntbackup, even to backup 2 simple text files, all open files are frozen for a moment. Somehow, if your machine contains a SQL Server instance, a dump for all databases is created to a virtual device.

Don't ask me why

Martin Rutten,

Wildher ICT Solutions

Julius Bichage SSC Journeyman Points: 97 More actions · Answer 9

Julius Bichage

SSC Journeyman

Points: 97

November 2, 2006 at 8:24 am

#669499

Thanks. Your contributions were helpful.

J

sivaprasad SSCertifiable Points: 6183 More actions · Answer 10

I am also getting this error messages. I am confussed is that NTBackup or SAN causing this problem

Sivaprasad S - [ SIVA ][/url]http://sivasql.blogspot.com/[/url]

Gladenstine SSC Rookie Points: 45 More actions · Answer 11

It seems like NTBACKUP tries to take a snapshot of the drive eventhough only one folder in that drives is selected for backup. This snapshot freezes the databases if their files are on the above drive.

Does anybody know if there is any solution for this other than the command line switch?

claire_chs SSC Journeyman Points: 86 More actions · Answer 12

I haven't tried this Hotfix yet. But it suggested this hotfix may fix the issue that ntbackup has. Below link for your reference.

http://support.microsoft.com/kb/903643