November 21, 2012 at 6:27 am
Hi, I have a doubt as writing to disk by the Sql Server.
We use the server with the settings below, and there is much difference between the time copies of file to a restore / backup talking about writing to disk (B / s).
Because of this, SQL is very slow compared to other servers
I want to know what can be the "lock" that limits SQL.
OBS. already have disabled the antivirus, for precaution (Symantec Endpoint Protection)
I used the Performance Monitor and Resource Monitor for measurements.
Formatted and installed 2 days ago (11/19)
Windows 2008 R2 X64
Processor: 2.4 GHz Xeon 3060
Memory: 8GB
drives:
Disc 1 - (Raid 0)
C: - OS / SQL Server
L: - Sql Server Log Files
writing:
- (File copy) 80 MB / s
- (Sql server restore / backup) 13 MB / s
Disc 2 - (Raid 0)
M: - Sql Server Data Files
writing:
- (File copy) 120 MB / s
- (Sql server restore / backup) 13 MB / s
Many thanks to anyone who can help.
November 21, 2012 at 8:34 am
Your file transfer speeds will never match SQL Server backup / restore speeds number for number. There is more work that SQL Server needs to do when doing the backup / restore than the simple I/O involved in a file copy. Having said that, are you comparing the performance to other SQL servers ? If yes, have you benchmarked the other servers at the OS level ? I generally use the SQLIO tool to do my benchmarking / stress testing. If you are using a RAID controller, I would also check the cache size of the RAID controller and ensure that the file size you use for the test is larger than the cache size(So you dont get spurious speeds where it performing I/O from cache).
November 21, 2012 at 9:39 am
Sorry, the only thing that slow is the restore, not backup as I wrote before.
Strange, the backup is done at 80 MB/s and restore only 12 MB??/s.
The other server has the same configuration as this, to be a pattern here.
The backup file is 18 GB (compressed), the base has 120 GB
November 21, 2012 at 11:32 am
brunnolira (11/21/2012)
Sorry, the only thing that slow is the restore, not backup as I wrote before.
Do you have 'Perform Volume Maintenance Tasks' enabled for your SQL Server?
November 22, 2012 at 4:39 am
I've add this yesterday, and nothing changed at all..
November 27, 2012 at 12:28 pm
Well folks, tks for those who tried to help me!
I thought the problem, was the RAID controller card.
after removing and reinstalling the windows, and do RAID in the OS, the speed of restore was 14Mbps :blink: and now 160Mbps 😀
The topic can be closed, problem solved.
Tks again!
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