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 as we discuss in our recent article "What's Missing From Your Disaster Recovery Plan?".
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. In our next entry we will discuss how the storage administrator's role will need to change to manage these processes as well.
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