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elwoos
Master Smack Fu Yak Hacker
2052 Posts |
 Posted - 2011-09-22 : 10:45:57
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Our friends  in our central IT team have told us that one of the systems they backup takes 4 hours. To my knowledge this isn't a SQL Server but it made me curious, how much data would there have to be on a single SQL Server (no clusters or other complexities), for it to take 4 hours to backup?Anyone have any clues?-----------What color do you want that database? |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2011-09-22 : 12:30:05
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| Depends on i/i subsystem speed, cpu, ram, other activity. And if they're backing up over the network, then it also depends on network speed and traffic. |
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elwoos
Master Smack Fu Yak Hacker
2052 Posts |
Posted - 2011-09-23 : 11:19:53
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| I was thinking for a pretty simple scenario, I may have misunderstood but I believe its from one part of our san to another. I dont know much about san's but I know they can be pretty quick, I'm not expecting hard and fast figures, just some sort of indication.-----------What color do you want that database? |
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Curt Blood
Starting Member
23 Posts |
Posted - 2011-09-23 : 12:41:42
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quote:
Originally posted by elwoos
I was thinking for a pretty simple scenario, I may have misunderstood but I believe its from one part of our san to another. I dont know much about san's but I know they can be pretty quick, I'm not expecting hard and fast figures, just some sort of indication.
Xpurts ownly please. Most urgent.(Sorry, couldn't resist)  |
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russell
Pyro-ma-ni-yak
5072 Posts |
Posted - 2011-09-23 : 13:14:13
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| One of my backups -- over a 1Gb LAN to a NAS -- takes a little over 20 minutes for 88 GB.Our SAN to SAN backups are MUCH faster. |
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Kristen
Test
22859 Posts |
Posted - 2011-09-24 : 07:51:54
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| The backups our hosting people do interfere with performance of the system, which I don't think shoudl be right? What's your experience?As I understand it:there is a dedicated NIC for their backup APP to useThe only thing backed up is a specific drive that contains the BAK files. There are no other files on that drive (although SQL might be creating a backup when the APP is pulling data ...)Its something I've been meaning to get some opinions on before we hit the busy Xmas shopping season ...Even our Log Shipping (i.e. when we copy TLog backup file to 2nd-server) causes performance degradation, and that is using a very low priority in order to have minimal impact on the local server. That is probably using the same NIC as the Web boxes that are talking to the SQL boxBut heck, I'm sure we're not LAN bandwidth limited. We've got 2 web servers and 2 SQL boxes sitting side-by-side. |
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jackv
Master Smack Fu Yak Hacker
2179 Posts |
Posted - 2011-09-25 : 02:09:39
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| Current environment I'm working on uses SAN snapshots. Does a few hundered GBs in a few minutes - onto another area. That backup area is then backed up onto tape- much faster , as there is less contention with Production serversJack Vamvas--------------------http://www.sqlserver-dba.com |
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Michael Valentine Jones
Yak DBA Kernel (pronounced Colonel)
7020 Posts |
Posted - 2011-09-25 : 05:21:18
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| In a recent test a SQL 2008 Enterprise Edition 64-bit 350 GB database backup from SAN using native compression (about 75% compression) with backups to 5 files in parallel (not mirrored) over a 1 Gbit LAN to a Windows file server took about 20 minutes when the file server was fairly idle, but took about 1 hour when the file server was loaded with backups from other SQL Servers running at the same time.Realistically, there are so many factors in play that the only way to know is to test. The load on the SQL Server, IO performance, network performance, target IO performance, backup compression ratio, etc. all play a role.CODO ERGO SUM |
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jen
Master Smack Fu Yak Hacker
4110 Posts |
Posted - 2011-09-25 : 15:50:59
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| You may want to check if TCP offloading is enabled, should be disabled based on experience. Disable it from the OS and NIC.Hth--------------------keeping it simple... |
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Kristen
Test
22859 Posts |
Posted - 2011-09-26 : 04:40:59
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| Thanks Jen. It rings a bell, so I think we must have reviewed that last Xmas, but I'll double check it. |
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Kristen
Test
22859 Posts |
Posted - 2011-09-26 : 08:23:47
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| I have double checked. We did try that last XMas, and it didn't make any significant difference I'm afraid. |
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elwoos
Master Smack Fu Yak Hacker
2052 Posts |
Posted - 2011-09-26 : 12:08:54
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| Thanks for the responses guys and gals they are exactly what I hoped for.-----------What color do you want that database? |
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Lumbago
Norsk Yak Master
3271 Posts |
Posted - 2011-09-30 : 06:29:56
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| I'd add that if a single backup were taking 4 hours I would do some serious revisions of the backup methods. 4 hours is a long period of time and requires a huge maintenance window every single day (if backup is daily of course). But of course...if we're talking massive amounts of data it might be a different story.- LumbagoMy blog-> http://thefirstsql.com/2011/07/08/how-to-find-gaps-in-identity-columns-at-the-speed-of-light/ |
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Just in time