SearchStorage.com

The following cross-section of midrange NAS arrays was selected based on input from industry analysts and... More...

This week's storage news:

ProStor Systems Inc. made InfiniVault 2.0 available this week, adding remote replication capability to the removable disk system.

With Version 2.0, InfiniVault customers can send copies of data to remote sites for disaster recovery (DR). It can also create read/write vaults to allow third-party applications and administrators to control retention policies, and includes a second gigabit Ethernet (GbE) port to segregate data from management traffic.

Mellanox launches 40 Gig InfiniBand switches

Mellanox Technologies Ltd. has made its latest IS5000 40 Gbps InfiniBand... More...

Mimosa Systems Inc. and LiveOffice LLC are looking to short-circuit the debate about on-premise email archiving vs. email archiving SaaS with a new offering that combines Mimosa's NearPoint on-premise email archiving software with LiveOffice's Mail Archive service.

"Each of our worlds will say 'We're the best thing since sliced bread,'" said LiveOffice CEO Nick Mehta of the competition between on-premise and hosted email archiving concepts in the last few years. "But the reality is that there are benefits to both."

"This is the first legitimate hybrid SaaS and on-premise email archive solution," said Brian... More...

Pixorial Inc., an online video-sharing website, turned to Xsigo Systems Inc.'s I/O virtualization director switch, Xsigo I/O Director, to build an infrastructure that will allow for quick scaling of storage and network bandwidth.

Pixorial lets users upload video to its website in any format, and they can edit the video and share it as high-resolution digital files or on DVDs. The website uses a co-location center in Aurora, Colo., for its main data center, but converts film and tapes sent in by users into high-resolution files at its Littleton, Colo.-based headquarters, said Joshua Terry, Pixorial's director of... More...

Startups Pivot3 Inc. and Seanodes are taking steps to increase the performance and scalability of their iSCSI offerings. Pivot3 is increasing the RAID protection for its Pivot3 Serverless Computing to RAID 6e, while Seanodes Inc., whose Exanodes software can turn commodity servers' internal storage into scale-out shared storage, is adding support for solid-state drives (SSDs).

Pivot3 adds RAID protection to serverless systems

Pivot3 is upgrading the Pivot3 Serverless Computing platform it launched last August. Pivot3's Serverless Computing eliminates physical application servers by moving... More...

No matter how much storage capacity you squeeze into an array, it's just a matter of time until that space is completely filled. Users everywhere are challenging existing storage resources with applications that proliferate media-hungry data files. This is where SAN expansion technology comes in.

This handbook takes an in-depth look at SAN expansion technology and offers advice on the many elements involved, such as integrating SAN and NAS, switch upgrades, disk array replacement and capacity planning tools.

Best Practice No. 1: Expanding or replacing disk arrays
Even the biggest disk array eventually runs out of storage space. Tiered storage? Data deletion? No matter. At some point, you'll still need to expand or replace your SAN. Here are eight best practices for disk array expansion or replacement.

Best Practice No. 2: Switch upgrades and replacements
Switches must provide a mix of performance, reliability and management versatility, while maintaining a reasonable cost per port. Here are eight best practices for switch upgrades and replacements.

Best Practice No. 3: Host bus adapter upgrades and replacements
Learn how to maintain control over HBA selection, eliminate bottlenecks, boost availability and how HBAs will interact with FCoE. Here are seven best practices for host bus adapter upgrades and replacements.

Best Practice No. 4: Selecting a storage capacity planning tool
To select a storage management and capacity planning tool, first calculate how much storage is available and how much of your total storage capacity is actually being used. Here are eight best practices for switch upgrades and replacements.

Best Practice No. 5: Integrating SAN and NAS
SAN and NAS platforms are often interconnected so their respective benefits can be pooled. However, storage administrators must take care when connecting SAN and NAS. Here are eight best practices for integrating SAN and NAS.

Best Practice No. 6: Integrating iSCSI and Fibre Channel, and make it work
Although companies of every size are embracing iSCSI SAN technology because of its lower cost and relative simplicity, there are situations where iSCSI and Fibre Channel coexistence makes sense. Here are eight best practices for integrating iSCSI and Fibre Channel technologies.

Best practices for SAN expansion include options for integrating SAN and NAS or iSCSI and Fibre Channel, evaluating capacity planning tools, as well as upgrading switches, disk arrays and HBAs.

By implementing the following green storage best practices, firms can use a mixture of technologies and tactics to control data center power and cooling costs and increase their storage energy efficiency.

Avoid overspending and overprovisioning.
It's obvious that spinning disk is the source of most storage power consumption, and unused spinning disk represents wasted energy. But there are several challenges in growing storage incrementally, including the organization's ability to accurately forecast storage capacity needs. Beyond capacity planning, it requires a relationship with a vendor who can support the incremental storage growth. The technology must also allow the storage to expand easily and with minimal disruption.

Revisit your tiering strategy.
Small, fast disks demand more energy than large, slow disks, so the distribution of data across various storage tiers can have a big impact on your power consumption. A study by EMC Corp. last year indicated that storing a terabyte of data on a 7,200 rpm 1 TB SATA drive is 94% more efficient than storing it on a 15,000 rpm 73 GB Fibre Channel (FC) drive. This provides an added incentive to ensure that storage service levels and tiers are properly aligned based on application and data value.

There are many situations where tiered storage allocations are far from ideally distributed. Understanding this distribution and developing a clearly defined set of service-level requirements to apply to new and existing applications can lead to substantial savings in equipment cost and energy use.

Revisit RAID policies.
Another facet of a tiered storage strategy is the RAID data protection policy applied to a given tier of storage. It's not so prevalent these days, but overprovisioning of RAID 1 or RAID 10 increases the number of spindles and power consumption. When additional performance or availability isn't required, the drive count can be reduced.

Consolidate storage arrays.
The more frames in a data center, the more power that needs to be reserved for them. Older arrays tend to be less efficient than the latest models, so reducing the number of storage systems is an obvious option, just as consolidating physical servers through virtualization is. Newer virtualization arrays may also offer enhanced functionality such as thin provisioning to improve utilization and further reduce energy consumption.

Establish power usage metrics.
Power specifications typically enter a storage infrastructure discussion only during installation planning. However, to truly align data center and IT infrastructure objectives, this will need to occur. Organizations like The Green Grid promote standardized data center efficiency metrics. It will also become necessary to establish metrics such as GB/kW or IOPS/kW, and to then determine these rates for each tier of storage as well as usage for the storage infrastructure in total.

Consider solid-state drives (SSDs).
While solid-state drives (SSDs) are still a new phenomenon for many, they can play a role in replacing power-hungry, high-speed, low-capacity disks. In addition to offering higher performance, EMC reports that on a per-IOPS basis, flash disks require 98% less energy. It's therefore imperative that organizations do their homework and understand actual performance requirements before making any substantial investment in this technology.

Consider massive array of idle disks (MAID).
At the other end of the performance spectrum is MAID technology. We know a significant amount of data currently stored on spinning disk is accessed infrequently. From an energy-consumption standpoint, the most efficient disks are the ones that aren't spinning at all, which is the rationale behind MAID. For archival data that still requires accessibility, this technology represents an attractive alternative to conventional, continuously spinning, nearline storage.

Make energy usage a buying consideration.
As the demand for green storage grows, vendors have realized that energy efficiency can be a competitive differentiator. It makes sense to factor this into equipment purchasing criteria, and to consider energy impact when architecting new storage infrastructures. Often times, the focus is on capital expenditures (CAPEX) and insufficient attention is paid to operation expenditures (OPEX). However, evidence is mounting in the server world that these lifecycle costs, including power and cooling, can actually overshadow CAPEX. Green storage best practices control power and cooling costs, and increase energy efficiency in your data center. Tiered storage, consolidating storage arrays, solid-state drives (SSDs) and MAID can help.

Server virtualization can lower costs and increase capacity on physical servers by sharing them among several virtual machines. However, there are a number of best practices to consider when using or thinking about server virtualization.

When using virtualization systems from VMware Inc. and other vendors, it's important to remember that there's a physical server with physical storage underneath the virtualization layer. This means that you still can't exceed the capacity of your basic hardware, and virtualization will give you less total capacity because of the overhead of the system. So while you can balance your load by putting applications with different peak loads on different virtual machines (VMs), you must still respect the limits of your hardware.

Because of this, server virtualization software requires a slightly different set of best practices when there are problems with your storage subsystem.

Poor I/O can impact the system

The most critical factor in a VMware installation is generally bandwidth. The I/O performance of your physical system will have more to do with the overall performance of the system than the storage capacity.

Anything that degrades I/O, such as a failed disk in a RAID array, will have a major impact on the performance of your virtualized system. If you're having performance issues, one of the first things you should check is I/O. For example, RAID arrays should continue to work even with a bad disk, but they will slow down considerably and likely affect your virtual machines as well.

Monitor virtual machine performance

Virtualization introduces a whole new level of performance statistics. In addition to being concerned with the performance of the underlying physical hardware, you now need to pay attention to the performance of individual virtual machines.

Fortunately, VMware can monitor a number of statistics to measure the performance of your virtual machines. For tuning and troubleshooting purposes, you should be familiar with these numbers, particularly disk command aborts and memory swap-in and memory swap-out.

Disk command aborts are requests that have timed out because the disk is taking too long to respond. This indicates a problem such as an I/O bottleneck or a poorly configured disk.

Memory swap-in and memory swap-out each measure activity in the virtual machine's virtual memory. A large number of memory swaps indicate that the VM doesn't have enough memory and its parameters need to be adjusted. It's important to note that this refers to memory assigned to the VM, not necessarily physical memory.

VMware's vCenter Server can help you make the most of server virtualization statistics. With this tool, you can maintain logs going back five years as opposed to the one hour maximum that the VMware ESX and VMware ESXi platforms provide.

Eliminate single points of failure

The failure of a single piece of hardware can take down a dozen or more virtual servers. To correct this, storage managers should carefully plan their storage infrastructure and eliminate single points of failure in their physical infrastructure. This includes such features as redundant data paths between the physical server and storage system, multiple host bus adapters (HBAs) on both ends of the storage-area network (SAN), and RAID or even mirrored RAID on your storage.

Ensure the write cache works properly

Because I/O is so important to virtualized systems, you need to ensure that the write cache on your RAID controller is working properly. For example, a dead or missing battery on the controller card can disable the card's write cache, which will lead to problems with the RAID controller. Among the best practices to consider when using server virtualization, and VMware in particular, are monitoring virtual machine performance and eliminating single points of failure.

The major airlines are masters of thin provisioning; they just call it overbooking. Using the extensive data they have about every flight and its occupancy, they can pretty accurately predict how many passengers with reservations will be no-shows. So, they overbook. That we don't actually encounter overbooked flights all that often is a testament to how good their data and predictive algorithms are.

Thin provisioning is a form of overbooking. With thin provisioning, you provision a certain amount of storage capacity while actually allocating less disk capacity than you provisioned for. The application thinks it has a certain amount of capacity available to it, when it actually has less.

"Many companies are concerned about thin provisioning because they think it could get them into a difficult predicament," said Mark Teter, chief technology officer at the Denver-based Advanced Systems Group. However, if you know your applications, users, data and usage history, it's unlikely you'll encounter problems from this type of storage overbooking.

Still, if you miscalculate or something unexpected happens, you may find yourself hitting capacity utilization thresholds. If this happens and you're forced to quickly acquire and deploy more disk capacity, it still isn't a fatal problem. The capacity has already been provisioned; usually, you just need to plug in extra disk.

Let's take a look at a few things you can do to ensure thin provisioning goes smoothly:

1. Know your data

"Airlines get away with [overbooking] because they have such a detailed history of passenger behavior. They know what to expect for each flight based on different circumstances. You can do the same with storage," said Greg Schulz, founder and senior analyst at Stillwater, Minn.-based StorageIO Group.

To take advantage of thin provisioning, you have to know your storage usage and trends. "That means knowing if your data is static or changing. You also need to understand the level of I/O activity and I/O patterns," Schulz said.

In effect, "thin provisioning presents an abstracted or virtualized view to servers and applications of how much storage has been allocated," Schulz explained. In this way, thin provisioning allows storage space that has been allocated to various applications or servers but not actually consumed to be shared. Given that so much storage capacity is vastly underutilized anyway, storage administrators who understand the data and usage patterns can feel confident practicing thin provisioning.

2. Focus on file systems first

"You can be selective in where you use thin provisioning. Use it first for file services like CIFS and NFS. File storage usually is over-allocated anyway, making thin provisioning easier and less exacting," Advanced Systems Group's Teter said. With thin provisioning, a company should be able to reduce the actual allocation of disk for file storage by 20%- 30%.

Thin provisioning is less necessary and more complicated when applied to databases and structured data. Here, the database applications like to tightly specify storage allocation, and managers are rightfully cautious about disturbing carefully tuned database applications by applying thin provisioning. It's no different from IT managers who are reluctant to put mission-critical transaction databases on virtualized servers until the technology matures.

3. Leverage all your spindles for better performance

Thin provisioning can actually improve storage performance if you create thinly provisioned virtual volumes that cross as many disk spindles as possible, Teter suggested. As a general rule, the more disk spindles handling the storage request, the higher the performance. With thin provisioning, you consume less physical capacity while getting better performance.

4. Use in conjunction with storage resource management (SRM) and data deduplication

"Thin provisioning is not a product on its own, but a feature," StorageIO Group's Schulz said. Like storage resource management and data deduplication, thin provisioning is being built into storage products in various ways. It should be combined with data deduplication and SRM as part of an overall storage management strategy. Storage resource management will provide usage data that enables the organization to thinly provision the storage better. When combined with data deduplication, the organization stands to increase utilization of existing storage while reducing the need for additional storage capacity.

3PAR Inc. and DataCore Software Corp. staked out positions in the thin provisioning market early on by selling data storage arrays and software that made extensive use of storage virtualization when allocating capacity.

However, storage vendors like Hewlett-Packard (HP) Co. and BlueArc Corp. use virtualization to enable what amounts to thin provisioning in other forms. It's storage virtualization combined with detailed knowledge of the organization's data usage patterns that make thin provisioning effective.

Thin provisioning allows storage capacity that has been allocated to various apps or servers, but not actually consumed, to be shared. This allows you to use less disk capacity.

As companies look to archive their user's emails for business and compliance and/or litigation reasons, finding an archiving product that fits your company's needs can be a time-consuming process. While cost is always a consideration when selecting any new technology, a user-friendly email archiving system must also be given strong consideration.

The No. 1 factor in positioning an email archiving project for success is user acceptance. If your system can deliver in the following three areas, you'll have much happier users.

Complete integration. Will the user see an unfamiliar Web link or a reassuring Microsoft Outlook or Notes window? This is the first question most users ask when they're being trained to use a new archiving system, and one that every information technology pro should keep in mind when selecting an email archiving product. The less hassle and more familiarity there is, the better the user experience will be.

Offline access. Can a user access the archive when they're on a plane? A system that cuts users off from the bulk of their mail just because they're not on the network is bound to generate complaints. It might also lead users to start "underground archives" in PST or NSF files, undermining your record-retention policy. While administrators can disable the creation of these personal archives, this further frustrates offline users with no access to their historic messages.

Mobile access. If you give users all of their mail no matter where they are or how they access the system, they'll love it. This is especially true when it comes to PST ingestion; the ability to access their personal historical mail from the Web on their BlackBerry is a powerful benefit that users will instantly understand and embrace.

This material originally appeared in Storage magazine.

Stephen Foskett is a frequent SearchStorage.com contributor. User acceptance is crucial to an email archiving project. Learn how complete integration, offline access and mobile access ensure a user-friendly email archiving system.