High Performance Storage Systems for SQL Server

Rod Colledge turns his pessimistic mindset to storage systems, and describes the best way to configure the storage systems of SQL Servers for both performance and reliability. Even Rod gets a glint in his eye when he then goes on to describe the dazzling speed of solid-state storage, though he is quick to identify the risks.


http://www.simple-talk.com/sql/performance/high-performance-storage-systems-for-sql-server/

Reliable Storage Systems for SQL Server

By validating the IO path before commissioning the production database system, and performing ongoing validation through page checksums and DBCC checks, you can hopefully avoid data corruption altogether, or at least nip it in the bud. If corruption occurs, then you have to take the right decisions fast to deal with it. Rod Colledge explains how a pessimistic mindset can be an advantage


http://www.simple-talk.com/content/article.aspx?article=1027

Installing and Configuring Openfiler with DRBD and Heartbeat (HA Cluster Setup)

Openfiler is a high performance operating system tailored for use as a SAN/NAS appliance. This configuration will enable two Openfiler appliances to work in an Active/Passive high availability scenario.

Disk Subsystem Performance Analysis for Windows

Analyzing storage subsystem performance is an art, not a science. Each rule has an exception; each system designer or administrator has a different combination of hardware configurations and software workloads to consider. This paper examines the performance of storage subsystems used by computers running the Microsoft Windows 2000, Windows XP, or Windows Server 2003 family of operating systems.
This paper considers performance from both the hardware and software perspectives. In addition, it discusses tools for storage subsystem analysis and design and provides rules of thumb and guidelines for system design and to solve the performance bottlenecks in specific configurations.

How to boot a VM in Hyper-V from iSCSI

Hyper-V virtual machines do not emulate an iSCSI HBA or allow you to pass a physical iSCSI HBA through to the virtual machine. However, as Hyper-V supports booting virtual machines directly off of physical hard disks, you can attach an iSCSI LUN to the parent partition and then boot the virtual machine off of it.
In order to do this you would need to:

1. Attach the iSCSI LUN to the parent partition.
2. Create a new virtual machine and opt to configure the hard disk later.
3. Open the settings for the new virtual machine and select the first IDE controller.
4. Select to add a disk drive.
5. On the disk drive configuration page select to use a physical hard disk, and select the iSCSI LUN.
6. Apply changes and close the virtual machine settings.

Now you can boot the virtual machine directly off the iSCSI LUN by just starting it up...

Reference: http://blogs.msdn.com/virtual_pc_guy/archive/2008/02/19/booting-hyper-v-vms-off-of-iscsi.aspx

Things to know before you build an OpenFiler SAN

These are some important tips that you may want to know before you go and choose the hardware that will run the OpenFiler software, if you do not want OpenFiler to be just a play toy:

1. Do not run OpenFiler on a desktop PC.
2. If you must use a desktop PC, use only Intel hardware (CPU, mainboard and network cards). Leave away any system that has nVidia, ATI, VIA or AMD hardware. The network cards can also be from Broadcom. Do not use network cards from Realtek, Marvell or others, put them on your usual desktops, not in your SAN.
3. Choose only "jumbo frames" enabled network cards from Intel/Broadcom. Search also for "teaming" or LACP or 802.3ad capable network cards. Do not forget that the switch also needs to know about these features.
4. Check all the chosen hardware against the RedHat HCL - https://hardware.redhat.com/. Do not use the hardware if is not on the RHEL HCL.
5. Do not use the latest and greatest of hardware, go for at least a year old hardware before the current kernel.
6. If you decide to buy some server (new or used), choose a server from a big server vendor: Dell, IBM, HP, Fujitsu-Siemens, Supermicro and others.
7. Do not use the RAID features implemented in chipset or add-on cards, expose every disk to the OpenFiler and use the software RAID implemented in OpenFiler. Buy simple add-on card for adding drives to the OpenFiler box, without RAID. If you do not find cards without RAID, disable the onboard RAID features.
8. For SCSI, use Adaptec, LSI Logic or AMI controllers. For SATA, use Silicon Image, Marvell or Intel AHCI controllers. Avoid JMicron and the likes.
9. Do not use USB or FireWire attached disk drives to use them as the main storage! Use them only for backup. Using OpenFiler on USB and FireWire disks will eventually result in tears.
10. Try to use SCSI/SAS disks. If you use SATA disks, use Seagate ES, Western Digital Enterprise/Raptor or Hitachi drives. If you must go with other brands/models, search for NCQ enabled drives.
11. Size your power supply carefully, SATA drives are particularly sensitive to voltage drops on the 12v rail. Choose a high quality and powerful PSU.
12. If you value your data, you must use a UPS on your OpenFiler system.
13. For the file system, use XFS. XFS is extremely resilient to faults, dirty shutdowns and other maladies that can cause data corruption.
14. Install Openfiler on a RAID1 set of drives, if one drive will fail your SAN will continue to work.

Keep in mind that OpenFiler is designed to store information. Sometimes very important information. Reliability is therefore the most important aspect of using OpenFiler, unless you don't mind losing data.

Make your own (free) NAS or SAN

If you want to build your own cheap NAS or SAN, there are available a couple of software packages that can transform a regular PC into a full fledged NAS or SAN (or both).

This is a list of the free NAS or SAN software that i found:

1. FreeNAS - http://www.freenas.org/
2. OpenFiler - http://www.openfiler.com/
3. unRAID - http://lime-technology.com/
4. ClarkConnect - http://www.clarkconnect.com/

There are others, of course, but these are the most prominent packages i have found after a few days of searching and reading on the net. And there are free.

The most advanced is OpenFiler, which is based on rPath Linux. In the past CentOS was used. Some people regret the transition to rPath.