Questions tagged [san]

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.

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5
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2answers
330 views

Slow checkpoint and 15 second I/O warnings on flash storage

Last couple of weeks we've been working on getting to the root cause of what could likely be the cause of the occurrence of these I/O issues and slowdown of the checkpoints. At first glance it looks ...
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1answer
52 views

Flash storage and auto-grow

Our databases files (data and log) of (a lot of) SQL Servers are hosted on flash storage (SAN), what would you use as auto-grow property for databases having size round 500GB (data) and 150Gb (log)? ...
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23 views

mysql pointing to 0:-1 partition

We have a Galera cluster on 3 nodes. On one of the nodes with SAN storage we experienced slowness in the cluster. iotop in the node with SAN storage shows that mysqld pointing to 00000...:-1 ...
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2answers
273 views

SAN IOPS figure

Recently we've been having high disk latency issue and wanted to benchmark one of our mount points on a preprod server to get an idea of how much IOPS, Throughput and latency our SAN is capable of. ...
4
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1answer
112 views

Logical Drives - I/O aside, does SQL Server care?

I'm one of those Accidental DBAs. Engineer at a medium sized company who worked for years to work without a DBA. We've since hired some (at my recommendation) and they're great but I'm trying to find ...
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2answers
44 views

High Level SAN Migration Strategy. Is this a good idea?

In the company I work for we are planning decommissioning an old SAN serving our production servers Which are 2 Nodes running 2 SQL Server instances using Clustering (one is the backup for one ...
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1answer
934 views

Use Windows 2016 Storage Replica for SQL Server failover cluster instance

We have two standalone servers with local storage. Based on our needs we have determined that we need to use AlwaysOn failover cluster instances. Can we use the "Storage Replica overview" feature of ...
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3answers
594 views

Migration of Always On Availability Group from old to new SAN within same data center

What are the steps required to move AAGs (version=SQL 2012 and OS=Windows 2012 R2 O) to new SAN within same data center? It is a virtualized environment. Instead of building new servers - can the ...
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0answers
103 views

Replication topology in MySQL 5.7

Our first and current approach : Current Replication configuration is Active - Active and R/W is split on both node . This is asynch-replication. Primary node is having RW ...
2
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0answers
28 views

Informix Innovator-c and SAN storage: How can we increase Innovator-C parallelism in high latency disk IO situations

When using Innovator-C against SAN storage (which is unavoidable in some cloud infrastructure situations) on a Linux (CentOS 6.x) system, write latency becomes the bottleneck in performance (we've ...
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2answers
622 views

Oracle vs SQL Server, 4k vs 16k block sizes

I was reading over these 3 articles: At my last company we only used MS SQL Server and MySQL, and if a server was strictly a database server we would setup the HDD to use 16k block sizes. http://...
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1answer
163 views

MDF, LDF, TempDb Location on same Hybrid SAN

I have seen this question asked before regarding SSDs or SANs, but never a Hybrid SAN. Also, most of the questions are several years old, so I figured I'd get a fall 2016 take on the answer. We ...
2
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1answer
565 views

All Flash Storage Configuration

Our co is getting a new SAN with all flash storage which would be attached to a physical 8 core 48 GB RAM server. I have been studying what is the best way to configure this setup. Our DB has mostly ...
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2answers
839 views

How to achieve Data synchronization in Active/Active clustering using SQL Server 2012 Standard Edition

I have a requirement of Active/Active clustering to be implemented using SQL Server 2012 Standard Edition in shared storage SAN. How the data share or synchronization between the two instances on the ...
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1answer
463 views

ms/write on tempdb data files are dead slow

I don't know why writes on my tempdb data files are extremely slow. ms/write on each of the tempdb data files reaches to more than 800 ms!!! that's even after I moved the 8 equally sized (7GB) tempdb ...
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0answers
54 views

Is it possible to query the avg time in ms per read/write

I was wondering if it was possible to obtain the avg block read and avg block write in ms with a query in SQL Server. If SQL Server knows how many IO requests are made for a given wait type and how ...
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1answer
41 views

What is faster Asynchronous SAN Replication or Asynchronous AAG?

If copying data from one datacenter to another, what would generally be the faster approach to propagate that data to the target datacenter, SAN Replication or AAG, i.e. block-level or transaction-...
5
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1answer
2k views

SQL Server on SAN, same LUN: one logical drive vs multiple

First, let me start by saying that I did notice there are multiple similar questions to this, but neither of them is exactly what I want to ask, and not one of them has a definite answer. Second, let ...
2
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2answers
426 views

SAN for SQL Server: One large spindle set for all loads, or discrete by load?

SQL Server 2014, Standard Edition (running under vmware, fwiw). Adding a Dell MD3420 DAS box. In the old school, you would set up discrete spindle sets for MDF, LDF, TEMPDB, BACKUP. E.g. MDF: Qty ...
0
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1answer
229 views

If my Data, Log and Tempdb drives are on the same LUN, are they using 1 physical drive?

My SQL Server Data, Log and TempDB resides on different logical drives. But when I check the drive properties under Hardware tab, their location are located on the same Port, Bus, Target ID and LUN. ...
0
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1answer
346 views

SMB 3.0 file share storage limitation

What is/are the limitation/s to move from SAN storage to SMB 3.0 on windows Server 2012 - SQL server 2012 enterprise production environment? I want to know the benefit of using SAN over SMB 3.0 as ...
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2answers
78 views

A new SAN - good idea for us? [closed]

I work for a small non-profit organization which has 2 infrastructure administrators. They have experience with Windows server administration and virtualization, but no experience with SANs or SQL ...
2
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1answer
98 views

Migrating system and user databases to a new server by moving the LUN

I have to replace a server. The system and user databases all reside on the E: drive which is a SAN LUN. The method they want to employ is to remove the LUN from the current server and present it to ...
2
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0answers
565 views

What is the ideal disk allocation size using our Nimble SAN?

I have seen many recommendations to use 64K disk allocation size for data drives such as from the SQL Server Setup Checklist on BrentOzar.com. The best practice guide for using our Nimble SAN with ...
3
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1answer
489 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 ...
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1answer
95 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 ...
5
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1answer
726 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 ...
3
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3answers
741 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 ...
6
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2answers
4k 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 ...
4
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1answer
382 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 ...
4
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1answer
175 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 ...
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2answers
675 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 ...
3
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1answer
117 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 stories....
6
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2answers
3k 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 ...
8
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4answers
10k 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) ...
6
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2answers
15k 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
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3answers
1k 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 san ...
2
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2answers
1k 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 ...
16
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3answers
4k 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 ...
31
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2answers
12k 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
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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 ...