Storage Requirements

When you are setting up storage for your AhsayCBS, please consider the following:

• Type of RAID to fit your requirement. (for local physical server or virtual environment)
• If you are deploying the storage locally, you are required to set up storage with redundancy, such as RAID 5 or RAID 6. This is important especially when you are delivering a backup service with good disk performance as well as good fault tolerance.
• Dedicated storage location for the system, user home and replication home.
• Physical storage, virtual storage, and cloud storage.

Redundant Disk Setup for Physical and Virtual Storage

We would recommend setting a rack mount server with several hard disk bays and/or attach a DAS for future expansion.

When you are setting up a rack mount server with 10 4TB hard disks, you may have concerns whether formatting the disk volume with RAID 5 or RAID 6. The following table lists out the differences between the 2 disk array setup.

As the cost of hard disk has reduced a lot nowadays, it is strongly recommended that you format your disk volume with RAID 6 that maximizes the protection.

Dedicated Storage on AhsayCBS

When you partition the disk in your new server, please consider setting up dedicated virtual disk volumes for operating system, application system, user homes and replication home (if Replication Server is enabled), respectively. It is a common practice that application system home, user homes and replication homes are not located in the system volume, which may fill up easily, causing the system to become unstable.

Space required for application system home with replication setup

If you have replication setup on the Backup Server, please consider to dedicate a volume for the application home with sufficient disk space to store the transaction log. As there is no exact formula for estimating the size of the application home, the amount of space used for the transaction log is dependent upon:

• The period of time that the replication reached the replay mode.
• The amount of daily backup data uploaded to your backup server.

For example, if daily customer backup jobs generate an average of 20GB of data. Your previous replication takes about 5 days to the replay mode, and then your application home partition will require at least 100GB (20GB x 5 days) of free disk space.

This is only a general rule of thumb, this estimation does not take into consideration the growth of daily backup data, or the accumulation of backup data on the backup server which will result in a longer time to reach replay mode.

Setup multiple dedicated disks for each replication server

If your Replication Server has setup several replication by multiple Backup Server, it is recommended that each receiver is located on its own individual disk. The advantage of this type of setup is that it minimizes the I/O on each disk, therefore improving replication performance.

Also, if one of the Backup Servers suffers an outage, there is the option of swapping the disk to the affected Backup Server.

Physical Storage

If you plan to have physical backup server, you are expected to have a fast local backup storage such as local hard disks, DAS or SAN. It is a solution for your business which wants to host the backup data with your physical backup server in your server room or data center.

Please avoid using network storage such as NAS, share drive on another computer as the backup and restore performance is lower.

Additional Disk Storage

Connect a Direct-Attached Storage (DAS) with e.g. a 12 hard disk bays filled with 4TB hard disks via the SCSI interface, extra SCSI controller card required.

With the above setup, it should be able to handle 100 users with around 30TB of storage and a total of 1000 backup sets. With this server setup, it is not yet reaching the server’s physical limitation. There are still other factors that may limit the growth of users, e.g.: network bandwidth. Also, it is easier to manage from administration point of view.

There are 2 assumptions:

• Each user has around 300GB of backup data, with constant 3% of changes daily.
• Each user account has configured 10 backup sets. These backup sets could be run on different machines and backup to the AhsayCBS at the same time.

AhsayOBM/AhsayACB backup clients are enhanced to utilize multiple threads for backup and restore. It is recommended to keep the maximum number of concurrent backup jobs on the AhsayCBS to 1000, to avoid potential performance problems.

File System Tuning for Virtual Storage Environment

If your backup server and user’s data are hosted on a virtual environment, you need to check on the following to make sure the performance has been optimized.

When you set up a disk to attach on a virtual machine, please consider choosing the “thick provisioning” option or the “allocate all disk space” option. This is because choosing “thin provisioning” or “non-allocate all disk space” option may slow down disk performance when the amount of data grows.

Please also consider running the user home on a dedicated virtual disk, which is configured on fast and non-busy physical disks.

Cloud Storage

If you are considering hosting your backup server instance with a commercial cloud service provider such as Google, Amazon, Microsoft Azure etc., you need to set up cloud storage for your user home, predefined destination or replication home as well.