Backup and disaster recovery processes are nothing new for enterprises running AIX on IBM Power Systems (formerly System p). For over two decades since AIX was introduced, system administrators have backed up data and applications to tape. Those backups required manual intervention to set up, run and confirm the completion of the jobs. Enterprise applications using the data typically could not be run while the backup jobs were in progress. Here, Knowledge Center contributor John Gay explains how you can better perform backup and disaster recovery for AIX and IBM Power Systems using a combination of high availability and continuous data protection technologies.
the days when companies operated only during standard business hours,
nightly backup windows were not impediments, as backups were performed
off-hours. But now, business hours have expanded. Many global
organizations, especially those that operate Web-based sales and
services, operate on a 24/7 basis.
Furthermore, backup jobs often take much longer to run because
databases are much larger than they were in the past. Faster tape
drives reduce the amount of time it takes to perform the backup, but
they do nothing to eliminate the problem of interrupting 24/7
Even when companies aren't in 24/7 environments, competitive
pressures often require them to keep their facilities running longer to
better leverage fixed assets. Again, this reduces the backup window.
Although it may not shrink to zero as it does for 24/7 companies, it
may still be inadequate to facilitate backup operations.
The trouble with tape-based backups
Beyond shrinking backup windows, tape suffers from other problems.
For one, despite today's high-speed drives, restoring a data center
from tape can take several hours or even days-particularly if the tapes
have to be retrieved from a remote location. For most of today's
businesses, this downtime can be catastrophic.
Another problem with tape-based backups is that they are created
only once a day, usually at night. If a disaster destroys a data center
(including any onsite logs), data updates applied after the backup
tapes were created will be lost. Further, companies that rely solely on
tape backups actually put more than a day's worth of data at risk. Here
While disasters are rare, data losses frequently result from human
error, malevolent actions or simultaneous disk crashes that overcome
the protection offered by RAID. In these instances, data must be
recovered locally, and rapid recovery depends upon having the backup
tapes on hand. Consequently, many companies hold the most recent backup
tapes on site; they ship yesterday's tapes to a remote backup site only
when new backup tapes are created the following night. Thus, these
organizations put up to two days' worth of data at risk.
It doesn't end there. Tape is fallible. It is estimated that as many
as 25 percent of the attempts to recover data from tape are less than
completely successful. Thus, an organization may lose three or more
days' worth of data if the most recent backup tape is still onsite (and
the most recent offsite tape is unreadable for some reason when a
Security is another issue. Being a physical medium, tape is
vulnerable to theft. If the data on it is not encrypted, it could fall
into the wrong hands when in transit to (or located at) a recovery
site. For these reasons, tape-based backups no longer offer adequate
disaster recovery protection for many of today's organizations.