Availability

How does Parallels Cloud Storage protect my data?

Parallels Cloud Storage protects against data loss and temporary unavailability by creating data copies (replicas) and storing them on different servers. To provide additional reliability, you can configure Parallels Cloud Storage to maintain user data checksums and verify them when necessary.

What happens when a disk is lost or a server becomes unavailable?

Parallels Cloud Storage automatically recovers from a degraded state to the specified redundancy level by replicating data on live servers. Users can still access their data during the recovery process.

How fast does Parallels Cloud Storage recover from a degraded state?

Since Parallels Cloud Storage recovers from a degraded state using all the available hard disks in the cluster, the recovery process is much faster than for traditional, locally attached RAIDs. This makes the reliability of the storage system significantly better as the probability of losing the only remaining copy of data during the recovery period is very small.

Can I change redundancy settings on the fly?

Yes, at any point you can change the number of data copies, and Parallels Cloud Storage will apply the new settings by creating new copies or removing unneeded ones. For more details on configuring replication parameters, see Configuring Replication Parameters .

Do I still need to use local RAIDs?

No, Parallels Cloud Storage provides the same built-in data redundancy as a mirror RAID1 array with multiple copies. However, for better sequential performance, you can use local stripping RAID0 exported to your Parallels Cloud Storage cluster. For more information on using RAIDs, see Possible Disk Drive Configurations .

Does Parallels Cloud Storage have redundancy levels similar to RAID5?

No. To build a reliable software-based RAID5 system, you also need to use special hardware capabilities like backup power batteries. In the future, Parallels Cloud Storage may be enhanced to provide RAID5-level redundancy for read-only data such as backups.

What is the recommended number of data copies?

It is recommended to configure Parallels Cloud Storage to maintain 2 or 3 copies, which allows your cluster to survive the simultaneous loss of 1 or 2 hard drives.