Short for 'Storage Area Network', a SAN is a network for block level storage. One or more controllers present logical drives (called LUNs) to one or more hosts through a switched fabric.

learn more… | top users | synonyms

3
votes
1answer
63 views

Why is SAN Replication is Causing Random Database Corruption?

Having a strange issue with a disaster recovery technology we're trying to implement. The environment in both datacenters is the same having VMWare and Dell Equallogic SANs, which are the same ...
0
votes
1answer
36 views

SQL Server : multiple databases with transaction log on one SSD array

I know for HDD arrays that having multiple log files from different databases has a performance hit as it changes the IO pattern from sequential to random for the array. So having an array per ...
1
vote
2answers
28 views

Multi server single database access [closed]

We have a database server (8 core + 32gb ram + 2tb hdd + gigabit network). SQL Server 2014 Enterprise Edition processor lic. We also have a web server (4 core + 16gb ram, 2tb hdd + gigabit network). ...
0
votes
0answers
22 views

Replicated databases across locations; delay in application

I have a replicated instance of database on different locations different SANs which is utilized for running a vendor supported application. However, I notice that there is a significant delay between ...
0
votes
0answers
41 views

Did another application use an Oracle block?

One of our production Oracle databases got hit with a corrupt block. Looking at the hex dump, the first part of the block seems to contain Microsoft Windows Event Log and Windows Registry information. ...
5
votes
1answer
271 views

SQL Server Database File Groups on a SAN: Relevant or Not?

I am about to build out a new SQL Server and I was planning to make extensive use of file groups. I expect heavy growth, and heavy read/write to 5 different databases on this server. I was planning on ...
0
votes
0answers
57 views

VM SQL Data and Log drives have one Block Size, SAN another. Issues?

Setting up a new SQL VM. What happens if VM data and log drives have 64K (recommended) block size but SAN (IBM DS3500 Express) was configured with a different block size? I want to avoid IO issues ...
3
votes
3answers
308 views

Slow SQL Server authentication, but fast SAN, fast querying?

I am asking you after days of research but I think I don't have required skills to understand what is happening. I have a slow authentication on a SQL Server 2008R2, which leads to a timeout for the ...
1
vote
1answer
495 views

Why does innodb_flush_method = O_DSYNC provide such a performance boost with SAN-backed storage?

I've seen some people suggest that O_DSYNC should be used with a SAN. The MySQL docs have this to say about O_DSYNC in general: In some versions of GNU/Linux and Unix, flushing files to disk with ...
3
votes
1answer
108 views

Storing Tlogs and data files on the same drive

I'm looking for some clarification of various things I've read. I understand it to be best practice to store your transaction logs on a separate drive (spindle) than where you MDFs and NDFs are ...
3
votes
1answer
117 views

Should I align my SQL Server file and growth sizes with the block sizes on my SAN?

It was brought to my attention that our (Hitachi) SAN handles data in 42MB blocks. It is tiered storage so each block is evaluated when the director makes decisions as to when it should promote/demote ...
1
vote
2answers
440 views

Understanding disk requirement to make fail over cluster

Please take a look at the following screenshot. I am trying to make SQL Server 2012 Fail Over Cluster using two nodes. As you know we need to have a shared SAN which will be used by both nodes to ...
2
votes
1answer
100 views

Sql Server & NetApp Sql Snap Manager

Does anyone use netapp's sql snapmanager? We are in the process of trying to decide if it is right for us. I know of the more popular features, but am trying to get some real life experience ...
5
votes
2answers
2k views

Multiple SQL Server data files on same SAN disk

I'm currently in the process of creating a new database, and have previously only ever used a single data file and a single log file. I've done some research online regarding the benefits of multiple ...
6
votes
4answers
7k views

SQL Server - Separating data, log, and TempDB files on a SAN

I have a SQL Server connected to a SAN. Our new storage vendor recommends that all LUNs span the entire disk array, which is RAID5. I would normally request 3 separate LUNs (data, log, and TempDB) ...
5
votes
2answers
10k views

SAN block size for SQL Server on 4KB NTFS

A potential customer wants to evaluate our storage system. They run Windows 2008R2 x64 with 4KB NTFS on a virtual test machine they've sent us. They did not seem to know this at hand, so I think it's ...
3
votes
3answers
697 views

Database IO comparison

We're running sql server on vmware. Our san is pretty new but still I think I/O is pretty crappy even though I'm supposed to be on separate spindels. Server speeds are: My client machine: Is our ...
2
votes
2answers
566 views

Investigating/Troubleshooting I/O Spikes

We have been experiencing some relatively large I/O (IOPS) spikes on the SAN that supports our production SQL Server. The spikes seem to fall at an exact time after the hour, each hour. We have ...
14
votes
3answers
3k views

Is there any benefit to defragmenting SQL indexes in a SAN environment?

Our SQL server lives on a SAN. It contains dozens of OLTP databases, some with several tables containing over 1m records. We have been running Ola Hallengren's index maintenance scripts weekly, and ...
28
votes
2answers
9k views

I/O requests taking longer than 15 seconds

Usually our weekly full backups finish in about 35 minutes, with daily diff backups finishing in ~5 minutes. Since tuesday the dailies have taken almost 4 hours to complete, way more than should be ...
8
votes
2answers
2k views

SQL Disk Setup Advice - TempDB, Log DB, Data file placement question

We have a very active database server with a ecclectic collection of applications running on it. Two of the busiest are a Laserfiche database that does document scanning and workflow processing all ...