Cloud storage will also affect the roles and responsibilities of
the storage manager as well. How those roles will change will
depend in large part if you are using cloud storage or if you are
providing cloud storage. In this entry we will look at how the
administration role will change for organizations using cloud
storage.
Organizations that use cloud storage as an external service have
essentially three areas in which they can use cloud storage--cloud
storage for backup data, cloud storage for archive data, cloud
storage for primary storage, or a combination of the three. The
storage administrator's role will change according to which of
these uses they leverage. The most popular, for now, use of cloud
storage is for backups and it will be the focus of this entry. In
future entries we will cover how cloud storage will change the
administrators job when it is used for archive or primary
storage.
In the backup use case, cloud storage can be either used as the
primary destination for backups or it can be used as a vault or
archive area. If cloud storage is used as the primary destination
for backup then this means that there will continue to be
on-premises applications connecting to on-premises storage, either
locally attached to those servers or via a shared storage
infrastructure like a SAN or NAS. In large part the storage
administrator's role as it pertains to managing primary storage is
unchanged from the pre-cloud storage condition.
The exception is that now there is not a backup area that needs to
be managed. This can be significant, since a large part of the
burden of managing and provisioning storage for backup data as well
as managing the off-site data movement is now handled by the cloud
storage provider. What the storage administrator does need to
manage though is the contract with the provider as well as the
costs to use of the providers storage assets. Since storage is paid
by the monthly GB used, the storage manager needs to be more
careful that accurate retention policies are maintained and that
data is not retained any longer than is truly needed. The storage
administrator may want to only store retained data in the cloud
that they know legally needs to be retained or that likelihood is
high they will need to recover it some day. They could then use
tape storage for data that they are not sure if they will need to
recover. Essentially tape becomes the "just in case" storage
area.
Another consideration for storage administrators looking to use
cloud storage as the primary backup storage area is how they are
going to recover data in the event of a failure. Recoveries from
cloud storage are always going to be an issue. While we may be able
to use deduplication and compression to reduce the amount of
bandwidth required when backing up to the cloud, we are not
typically able to leverage these technologies when restoring data
from the cloud. In most cases, all the data has to come back.
There are three methods to deal with the lack of recovery
bandwidth. The first is to live with the time it takes or leverage
a cloud storage providers ability, if they have it, to ship data to
you on portable hard drives. A second method is to develop a
hybrid-like approach that keeps a small portion, typically the
latest backup, of the data on premise. This may add a little to
management time to make sure the on-premises area has enough
storage capacity to store those backups. A third method is maybe to
not count on the backup process for time-sensitive recoveries at
all, but to use application replication products.
The next area that organizations tend to explore for the use of
cloud storage is storing archives of data. This can be long-term
retention of inactive files or could be for vaulting of backup data
from an on-premises process.
- George Crump is lead analyst of Storage Switzerland, an IT
analyst firm focused on the storage and virtualization
segments