StorTrends Whitepaper: D2D2T Whitepaper
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Table of Contents Introduction: The Need for Reliable Implementations 4 Traditional Tape 4 The Limitations of Tape 4 Data Recovery Issues with D2T 5 One Step Beyond: Disk-to-Disk (D2D) 5 The Head of the Class: Disk-to-Disk-Tape (D2D2T) 6 A Detailed Look at iscsi IP-Storage in D2T and D2D2T 7 Conclusion 9 Why AMI? 10 3
Introduction: The Need for Reliable Implementations Organizations today have a massive amount of critical data that needs to be preserved. The regulatory requirements encompassed in the Sarbanes-Oxley Act as well as an overall increased awareness in industry of the need for tighter IT controls have only added to this need. Not only does this data need to be preserved, but it also needs to be stored securely, and it needs to be readily accessible, even if the backup media is stored offsite. In the event that a data anomaly or the like requires the data to be reloaded into the system, for example after data loss, or in the case of an audit procedure, the organization must be certain that uncompromised data can be accessed in a timely manner. Traditional Tape In many companies, from small and medium-sized businesses (SMBs) to enterprise-scale corporations, backup solutions are often comprised of a backup server running backup software that dumps data to a tape device, usually according to a periodic schedule based on the critical-nature of the data involved. solutions such as these are commonly known as Disk-to-Tape backup systems, or D2T. The top three types of data servers that companies focus on for backup operations are their database (particularly accounting or ERP databases), along with file and e-mail servers. Depending on the backup policy of a particular company, backups are performed either incrementally or fully. Incremental backups are performed at least once a day, while full backups are performed no less than once a month. Once a system backup has been made to tape media, the backup tapes are stored in a secure, environmentally controlled, and oftentimes offsite location. Gigabit Ethernet Switch Server XPress Tape Offsite Archive Figure 1: A Typical D2T Deployment The Limitations of Tape Most industry analysts concur that tape storage will maintain its place in the backup scheme due to archival and regulatory reasons, along with its shelf life and durability. However, as we will see below, D2T backup strategies have multiple points of failure, including failure of the tape itself. Tape restores fail for a variety of reasons, including media errors, physical damage or loss, corrupt indices, and the like. For all of the simplicity, security, and peace of mind that D2T backups offer, they are burdened by the following limitations: Each server must be backed up individually or interleaved, contributing to a longer overall recovery time. Large backups can span more than one tape and therefore require that a staff member be physically present to manually swap tapes. Tape swaps often occur at night or early morning, due to the timing of most backup schedules. As expensive as this might seem, it is still preferable to an automated system, as software and hardware for automated tape drives are typically cost prohibitive. During backup to tape, data cannot be restored. A commonly quoted statistic is that one in five tape backups fail. However, according to the Yankee group, 42% of all tape restores are known to fail; the Gartner group similarly quotes 71% failure, and Strategic Research claims a failure rate of 54%. The reliability of large backups can be compromised due to one bad tape, which renders all tapes in the batch useless. The large RTO and RPO of tape backup restores (see below for a definition of these terms) The physical and technological limitations of tape are not the only reason why more and more companies are moving to disk backups. The data security issues are increasingly moving to the forefront of user s discontent with tape. These security issues are compounded by the regulatory requirements described earlier in this document. Here are some recent examples of vulnerabilities 4
of strict reliance on D2T backup: In February of 2004, a large US bank lost a single magnetic tape with information on roughly 120,000 customers while it was being shipped by truck from a data management center in Singapore. The tape held names, addresses, account numbers and balances. It was never found. In early May of 2005, the same large US bank lost an entire box of tapes from its financial division in transit by one of the largest privately owned shipping companies. Although the tapes were encrypted and were not known to be accessed, the news of their loss created a media frenzy. Four million customer files where compromised. The large US bank that lost their tapes twice has stated that they will begin sending backups electronically to a secure offsite location. Also in the same month, a large media and entertainment company said that computer backup tapes containing data on 600,000 individuals were lost by an outside data storage firm. Unfortunately, stories such as these are not uncommon, and though spectacular, serve to drive home the data security risks inherent in outsourcing backup procedure 1. In response to these concerns, it should be pointed out that some tape backup companies are developing tape encryption products. However, at this point in time this is somewhat a new, developing technology, and time will tell whether or not this is a solution to the data security problems imposed by this model. Data Recovery Issues with D2T As noted above, traditional tape backups present several challenges for providing full protection of critical data. Tape backups are typically performed at night or during weekends; with a tape backup routine, in the unfortunate event of data corruption or server failure, data recovery from only the previous night s or weekday s tape archive is possible. The RPO (Recovery Point Objective, or the most recent point in time where uncorrupted data is certain to exist) in this scenario is not attractive, due to the amount of time that will have passed before the lost data can be restored. Additionally, the RTO (Recovery Time Objective, or the time limit established to restore business processes to normal functioning level) is not attractive if a tape copy has to be physically located and retrieved from an offsite location, particularly in the case of mission critical applications or when facing pressing data audit conditions. Because of the unappealing RTO and RTO presented by D2T backup schemes, it is worthwhile to consider certain alternatives for lowering RPO and RTO, since in a sense a backup is not very worthwhile if the time needed to make use of it in a restore procedure is unnecessarily lengthy. One Step Beyond: Disk-to-Disk (D2D) In response to the security and integrity concerns over strict D2T backup, many corporations are gravitating away from tape, either by integrating disk-based storage into their tape backup solutions, or by completely eliminating conventional tape backups and backing up directly to disk. This type of backup solution is known as Disk-to-Disk (D2D), and by adopting it, the limitations of conventional tape backups can be overcome to a certain degree. As the name implies, disk-to-disk (D2D) backup moves backed up data to a separate disk-based appliance, commonly over a network connection. File/ Application Servers Gigabit Ethernet Switch Storage Area Network Figure 2: A Typical D2D Deployment 1 New York Times, The Scramble to Protect Personal Data, June 09, 2005; USA Today, Tapes with data on 3.9M missing, June 07, 2005 5
One of the main advantages of this approach is that non-tape backups can easily be transmitted to an offsite location via Ethernet, and stored directly to disk. A second reason why D2D is gaining popularity is because disks are faster than tape devices, which reduces the backup window by a sizeable amount. Other factors have also served to increase the attractiveness of D2D backup, such as the rapidly falling prices of disk-based storage, the increasing capacities of today s hard disks, and the reliability and speed of restoring from disk-based backups, in comparison to the involved process of a restore from backup tapes. Simplify and Recovery Organizations can simplify their backup and restore procedures by deploying disk to disk (D2D) backup, by taking advantage of falling disk prices and increased disk capacity and spindle performance, while keeping the option to use tape backups when necessary. Data is a corporate asset and is exposed to loss through a variety of reasons, including human error by accidental deletion. Traditional approaches to its protection are flawed and are not efficiently able to keep pace with the current explosion of growth. Recent innovations solve the complexities associated with ensuring simplicity and efficiency of business data protection tasks. Some of the benefits that organizations can realize by utilizing D2D features include: Primary storage, backup disk volume, and tape provisioning from a single appliance Tape device sharing among multiple backup servers Simplify and Recovery Shrink or eliminate backup windows, without affecting performance Improve Recovery Point Objectives, while decreasing Recovery Time Objectives Minimize system and application downtime Eliminate performance degradation Reduce, if not eliminate, tape restores Ensure faster and more reliable restores Simplify growth and data management by consolidating multiple remote locations to one D2D backup repository Simplify security while increasing availability The Head of the Class: Disk-to-Disk-Tape (D2D2T) Although the simplicity and reliability of a D2D backups solution sounds ideal, most backup policies still call for the use of offsite backup storage on tape. Additionally, major obstacles to the substitution of tape for disk are added start-up and operational costs involved in the transition. Specifically, many backup software companies now charge additional fees for disk-only backups. To soften the blow, a practical solution might be to implement a mixture of tape and disk backups for different purposes; for example, by making incremental backups to disk, and full system backups can be to tape. One leverage point in a scenario such as this is that D2D backups can be either onsite or offsite. s to tape can take place during normal business hours because the data can be staged on disk prior to backup. This type of backup solution is commonly referred to as disk staging, or Disk-to-Diskto-Tape (D2D2T). In short, in disk staging a network backup server will write data locally to a storage disk (or disk array), and then copy the data from there to the tape device. An alternative to this approach is for the backup software clients to copy their backup data to a shared volume on the network, and then for the backup server to push the backup data from the shared volume to tape. 6
The illustration below provides more detail on how the D2D2T backup proceeds, and gives an idea of how data availability is maintained throughout the process: 1 2 Servers Gigabit Ethernet Switch Tape XPress 3 Storage System 4 Offsite Archive Figure 3: A Typical D2D2T Deployment 1. can continue to access data during a backup of the servers 2. All servers (2) are incrementally backed up and staged to disk (3) at the same time. The disk can be physically located in another building or across the country in a satellite office. 3. The staged incremental backups are held on disk for three months. A complete backup is transferred to tape (4) once per month. 4. Tapes are sent offsite for secure storage. Briefly, some of the many benefits of D2D2T backup as described above include the following: All servers can be backed up concurrently. Tape swapping can take place during regular business hours. During backup to disk, data is available and can be restored. A company s current tape backup infrastructure can remain in place with only a slight modification to the company s backup policy, while fulfilling the company s legal obligation to providing tape backups. The combination of disks and tape as storage media is more reliable than either single media type. Disk backups can be RAID protected. Tapes can be stored in a secure, climate-controlled, offsite location. It must be pointed out that although this strategy does not eliminate the problem of lost or compromised tapes completely, it is, however, a step in the right direction. A Detailed Look at iscsi IP-Storage in D2T and D2D2T We will next look in more detail at how an iscsi IP-Storage appliance can be incorporated into the two major approaches for and Restore options, D2T and D2D2T. First, we will see how iscsi works together with a Disk-to-Tape (D2T) backup solution, designed for environments that have one or more backup servers and a tape-based backup scheme already in use, but are seeking an more efficient alternative to their current deployment. 7
How D2T with iscsi works in a single or a multi-backup server environment: Servers 2 3 Gigabit Ethernet Switch 1 IP-SAN iscsi Storage System Tape 4 Figure 4: D2T with iscsi Storage Device, Multiple Servers Present 1. An iscsi disk(s) is provided to each of the multiple backup servers 2. The backup servers complete their backups to these iscsi based disks 3. The single physical tape unit is presented as iscsi tape devices to each of the backup servers* 4. Once the backup jobs are completed to the disks, they are scheduled for transfer to the iscsi connected tape device, according to the administrator s schedule and the functionality of the backup software *This innovation eliminates the need for multiple tape units or expensive Fibre Channel-based units with high connectivity costs. Note that this solution would work equally well with one or with multiple backup servers. The only difference is that backups are made sequentially to the iscsi device in the case of multiple backup servers. To elaborate, with this option, a single iscsi IP storage appliance enables the following two functions in the D2T backup scheme: iscsi-based backup storage disks: For use as the target disk(s) to which the backup server(s) stores the backup sets. External Ultra-320 SCSI connector: Facilitates the connectivity of virtually any tape device. This tape device is then presented to the backup server as an iscsi tape device for use in their implementation of D2T. In environments that require multiple backup servers, the iscsi appliance delivers multiple iscsi disks to service the disk-based portion of the D2T solution. Through the ability to present the physical tape device as an iscsi tape device, the sharing of a single tape unit can be accomplished. Next we will examine how iscsi IP-Storage appliances can be incorporated into D2D2T backup solutions to make them more robust and flexible. For this example, we will examine an all-in-one, four-function disk-to-disk-to-tape (D2D2T) solution designed for environments that do not currently have a backup server, or for those that are seeking a more efficient alternative to current deployments. This option takes advantage of the power of snapshot technology to provide seamless backup with no interruption to applications, by operating in the background of the application server. 8
How D2D2T backup works with no current backup server: 2 3 1 IP-SAN iscsi Storage System Tape 4 Figure 5: D2D2T with iscsi Storage Device, No Server(s) Present 1. An IP-SAN appliance is added to the network, in order to provide an iscsi disk for use by the application server. 2. Through Microsoft VSS or an application-aware agent, the backup application initiates an instantaneous snapshot of the file system where the applications store their data 3. From this snapshot, a non-disruptive backup of the file system s contents is completed to the embedded storage container. The contents of this container can also be accessed by a remote backup server, via a CIFS, NFS or HTTPS share. 4. Seamlessly and automatically, the backup set is then transferred to the tape device. The frequency of the disk-based backup cycles is determined by an administrator-configurable policy engine of the backup software stack. With this option, a single iscsi appliance enables the following 4 functions in the D2D2T backup scheme: iscsi-based primary storage disks: For use as the primary storage repository for applications such as Microsoft Exchange, Microsoft SQL Server, Oracle or Windows file servers. Embedded Storage Container: Facilitates storage of backed up data and can also be exposed as a SMB, NFS, or HTTP share for offsite backup data access. External Ultra-320 SCSI Connector: Facilitates the connectivity of virtually any tape device. Software Solution: Enables the delivery of the complete D2D2T backup and recovery solution Conclusion What makes D2D2T backup so effective? We have seen how D2D2T is the best, most reliable solution for backup, combining the best attributes of both tape and disk-based backup schemes. The ubiquity and long shelf life of tape can be leveraged, while D2T s poor RTO and RPO can be addressed. Conversely, the expense of additional disk storage and the licensing fees that backup software vendors often charge to support D2D backup schemes can be ameliorated to a degree. While D2D2T strikes a good balance between D2T and D2D, iscsi makes D2D2T even better, in two ways: by eliminating the need for a dedicated backup server, and by providing CDP through the use of snapshots. Granularity of backups can be reduced down to the order of minutes, greatly improving the poor RTO and RPO of D2T backups. s can be performed in the background by offloading to the iscsi storage device, so application performance is uninterrupted and not degraded. What makes American Megatrends line of StorTrends storage appliances the right choice for D2D2T backup? We have seen how the flexibility and power of iscsi-based IP-Storage devices can bolster data protection in D2D2T backup scenarios, eliminating the need for a dedicated backup server, and allowing for near-continuous data protection. StorTrends iscsi-based IP-Storage appliances from American Megatrends (AMI) offer some of the most advanced snapshot capabilities in the market today, allowing administrators to simplify backup execution while ensuring faster and more reliable data backup and restoration. With StorTrends itx Storage software, preinstalled on every StorTrends IP-SAN storage appliance, backup windows, dramatically reduced with D2D backups, can be eliminated altogether. StorTrends itx advanced snapshots capabilities reduce 9
backup windows that once lasted hours to minutes or even seconds. AMI StorTrends implements D2D2T backup using the following innovations: Flexible solution options tailored to your specific environment Snapshot (to virtually eliminate the backup window) Snapshot scheduler, allowing you to automate when the backups are to be taken Replication (to copy the snap shot to the secondary storage unit) StorTrends appliances enable near-instant recovery of access to backup data sets from a remote location, with no backup data loss. Organizations can seamlessly recover from site outages almost instantaneously, through quick re-syncs of unsynchronized backup storage repositories. AMI s Disaster Recovery capability is based on the following features in StorTrends itx: Snapshots to protect data from logical errors, such as accidental deletions or virus attacks. Replication copies of data to the disaster recovery site. Additionally, AMI is able to provide near-cdp, by utilizing several of the snapshot technology innovations available in the StorTrends itx box: Snapshot technology that utilizes Redirect on Write method Almost unlimited snapshot capacity, allowing snaps to be taken every few minutes Minimal performance degradation when snapshots are enabled Easy, quick rollback to any snapshot Find Value with StorTrends, by Lowering Capital Expenditures & Operational Costs AMI StorTrends solutions help organizations lower the cost and effort required to support storage resources by consolidating resources, simplifying management and reducing unused spindles. Some of the many advantages of storage consolidation include: Higher utilization of available storage Use of standard hardware and networking technologies, simplifying maintenance Management of more with less, by reducing the time it takes for existing staff to manage your data Allowing for heterogeneous connectivity between servers & storage Standardization of storage, eliminating multiple points of support Elimination of system downtime by seamlessly & non-disruptively adding or expanding storage to production servers Reduce Complexity StorTrends use of iscsi technology allows existing network personnel manage the new storage environment, foregoing the need for extensive additional training or new storage administrators as with typical FC SAN environments. AMI also deploys Commercial Off-the-Shelf (COTS) hardware, to offer the assurance that the latest developments in hardware technology are in the box. AMI operates on the premise that custom designed hardware has long development cycles, and that many of the features in custom designed hardware can often be provided by creative implementation in software. For example, AMI s ManageTrends software allows monitoring and control of the StorTrends itx product, to simplify configuration and set-up, and make quick work of normally complex, time consuming tasks. Why AMI? AMI offers a wide array of disaster recovery and high availability solutions for your business needs. We provide services that range from storage needs analysis to the design and implementation of a custom disaster recovery solution. We can help your business plan for when things are at their worst while reduce costs and complexity of your storage environment. For more information on AMI StorTrends solutions, visit www.stortrends.com, or contact a StorTrends Sales Representative by email (sales@ami.com) or by calling (800) U-BUY-AMI. 10
Whitepaper This publication contains proprietary information that is protected by copyright. No part of this publication can be reproduced, transcribed, stored in a retrieval system, translated into any language or computer language, or transmitted in any form whatsoever without the prior written consent of the publisher, American Megatrends, Inc. 2012 American Megatrends, Inc. All Rights Reserved American Megatrends Inc. 5555 Oakbrook Parkway, Building 200 Norcross GA 30071 t: 770.246.8600 Sales & Product Information sales@ami.com t: 800.828.9264 Technical Support stortrends-support@ami.com t: 770.246.8761 www.stortrends.com