The Trouble with Backups
Backups are central to any data protection strategy, but by some estimates more than half of all backups fail either in whole or in part. When you look at the reasons for why they are failing, the same issues come up again and again. Below is a list of the common problems that cause backup failure, in decreasing order of frequency.
1. Media failure
o In the case of tape, this means making sure you follow the vendor's directions for handling and storage, replacing the tapes regularly and cleaning the drives according to the manufacturer's schedule. It also means discarding any suspicious tapes.
o Disks can fail as well although at a lower rate than tape – use disk arrays with redundant components and hot spare disks for best protection.
2. Human Error – Probably the most prolific cause of backup failures
o Good idea to take the person out of the loop as much as possible. Ideally, backups should not require any human action on a daily basis.
3. Software failure
o Sometimes new software or new versions of software can cause backup failures. For example, Service Pack 2 (SP2) for Windows XP turns on the firewall by default.
o Misconfiguration - Modern backup software is extremely flexible; in other words, you have a lot of options to choose from and choosing the wrong options can result in incomplete backups or backups that fail totally.
o Review configurations regularly as resources are added and shifted and priorities change, the list of files to be backed up needs to change as well.
4. Hardware failure
o Tape drives, libraries, disk arrays and other backup hardware can also fail. Most of the causes and failure conditions for backup hardware are the same as for other kinds of hardware, but there are a few conditions that are specific to backup systems.
For example, drift produces a particularly nasty kind of failure in tape drives. As the drive ages, the heads slowly wander out of alignment. As a result, other drives can't read the tape -- and the drive can't read a tape it wrote some time ago. The nasty part of this is that the drive can almost always read a tape it just wrote, so the tape passes an immediate verification step in the backup process without complaint.
5. Network failure
o This is a less prolific source of backup failures because the network, LAN/WAN, is used for much more than just backup, so problems will tend to become obvious before they can hurt your backups.
o Backing up over a network can increase efficiency by reducing the number of backup devices to manage and maintain.
Whatever the cause of failure, the best way to keep them from damaging your organization is to verify your backups by performing regular test restores. Testing your backups regularly won't prevent backup failures, but they can help in noticing the issue and this will allow you to fix the problem before you really need those backups and you get a nasty surprise.
Avamar Offsite Backup from Keystone AEA1
What is Avamar?
Avamar is a backup solution made by EMC. Built on a grid architecture, it employs patented redundant array of independent nodes (RAIN) technology in order to provide failover, fault tolerance, high performance, high availability, and elimination of single points of failure in a backup solution.
Benefits of Avamar’s efficiency:
• Avamar can continue to provide reliable data protection and access, even if a server node fails or becomes unavailable, since data stored on any node can be reconstructed from the other nodes.
• Avamar also protects itself with twice daily internal checkpoints that can be used to roll back to a
consistent state should an integrity check fail during the daily, scheduled integrity checks of all data stores. As a result, Avamar eliminates the risk of “silent” data loss or corruption, which is common with tape archives.
• Avamar automatically load balances data across all available Storage Nodes for optimized scalability and performance for backup and restore.
• Data can be encrypted both in flight and at rest for added security.
• Utilizes patented global, source data deduplication* technology to identify redundant data segments at the source – before transfer across the network. Moving only new, unique subfile variable length data
segments, reducing the daily network bandwidth required to do backups by up to 500x thus providing up to 10x faster, daily full backups across existing LAN/WAN bandwidth.
• By storing just a single instance of each subfile data segment across the entire grid, Avamar reduces total back-end backup storage by up to 50x for cost-effective, long-term, disk-based recovery.
• Avamar agents run in low priority or “nice” mode, so they do not contend with other application vying for CPU resources on client systems.
• Avamar’s intuitive interface allows end users to quickly recover their own data.
• Immediate, fast, and reliable, single-step recovery - Avamar stores all backups as virtual full images, which can be immediately recovered in a single step to any system running the Avamar agent. There is no need to restore from the last good full and subsequent incremental backup to reach the desired recovery point. • Management is done via the Avamar Administrator, a graphical management application used to manage
backup policies, datasets, schedules for automatic backups and retention policies. It is also used to manage users and clients, do on-demand backups and restores to any system with a client installed, monitor activity and view reports.
• Backup client can be loaded on as many clients across your organization as desired, no per computer/server license is needed.
o Avamar supports the following clients and agents:
Windows 2008, 2003, 2000, Vista, and XP – protection of all FAT or NTFS data and Windows system state if desired
Unix – variety of Unix operating systems, including Solaris, HP-UX, SCO, Free BSD, and IBM AIX
Linux – Red Hat and SUSE
Mac OS X - PowerPc and Intel platforms Netware on Intel platforms
Microsoft SharePoint Lotus Notes/Domino
Open Enterprise Server (OES) Linux for NSS file systems – Novell OES 2 on Intel platforms
Oracle databases - utilizes Oracle Recovery Manager to provide fast and automated protection while maintaining online availability
Microsoft SQL Server databases - hot backups of SQL servers or databases
Microsoft Exchange servers - backup Exchange at a server, mailbox, or message level DB2 databases – fast and automated protection while maintaining online availability of
*Enterprise data is highly redundant, with identical files or data stored both within systems and across systems. Unique data segments are backup up only once across the enterprise thus changes generate only a small amount of incremental backup data. Edited files also have tremendous redundancy with previous versions. Compared to traditional backup software that stores redundant data over and over, Avamar uses source data deduplication to eliminate redundancy and speed up the daily backup process.
Avamar Rates at Keystone AEA1
Other Online Backup Providers
Barracuda
(http://www.barracudanetworks.com/ns/products/backup_overview.php):• The Barracuda Backup Service combines an onsite appliance with a monthly subscription that replicates data offsite.
• Starting at $50/month per 100GB of data for offsite storage (doesn’t include cost of onsite appliance). • Offsite storage cannot be purchased separately.
Carbonite
:Carbonite “Home”(h ttp://www.carbonite.com):
• Unlimited backup for only $54.95/year per computer. • Not for server operating systems.
• Supports XP, Vista, Windows 7 and Intel-based Macs with OSX 10.4, OSX 10.5, OSX 10.6. CarbonitePro (http://www.carbonitepro.com):
$0.50 per GB per month Supports:
• Windows XP, Windows Vista, Windows 7
• Standard 32-bit and 64-bit versions of XP and Vista • Windows Server 2003 & 2008.
Does not support:
• Older versions of Windows (Windows 98, Windows 2000, and Windows ME) • Linux operating systems.
Mozy:
EMC acquired Mozy in 2007, which now operates as a wholly-owned subsidiary with full access to EMC resources and assets.
MozyHome (http://mozy.com/):
• Unlimited data backup only $54.45 per year.
• Customers can also get a 2 GB account for free — and assign up to two computers to one account. • Unlimited users may add up to five computers to their account and must purchase an additional license
($4.95/month) for each computer added.
• Supports Windows 7, 2000, XP, and Vista (32 & 64 bit), as well as Mac OS X 10.6, 10.5, & 10.4. • Not for servers.
MozyPro (http://mozy.com/pro):
• Desktop Licenses: $3.95 + $0.50/GB per month • Server Licenses: $6.95 + $0.50/GB per month
