Some days ago I discovered that Quantum is offering a free virtual appliance of their DXi Backup to Disk series and I thought this would be a cool thing to have in my lab. I’ve deployed two of those appliances right away to learn about Quantum’s technology and if it could be a product for future projects. This post should reflect my thought, findings and some general information about deduplication appliances.
Backup to Disk with inline Deduplication and Compression
Those appliances no matter if virtual or hardware are designed to provide storage capacity primarily for backup or archiving purposes. This storage capacity can be presented via CIFS, NFS, Virtual Tape Library (VTL) or via OpenStorage (OST) API. So basically those appliances act as backup repository/target.
The DXi series comes with a simple web interface which enables easy setup and management, but I admit the design needs some improvements. The following screenshot shows how easy it is to create a file share.
I’ve used my Veeam B&R installation and attached a CIFS share using Active Directory authentication as new backup repository.
As data comes in it gets de-duplicated and compressed inline which allows to write way more logical data onto the appliance as physically is actually available. So for those of you looking for a way to store as much data on disk as possible, such an appliance would probably a good choice.
As many of you probably know, Veeam also offers a pretty solid deduplication which works on a per job basis. So having a global deduplication across all jobs can help to save even more space. But the benefit of a deduplication engine with a variable block size already kicks in using just a single job. (Dedupe AND compression enabled in Veeam! Compression should be disabled). There is a best practice guide available for Veeam & DXi right here.
Now having the data written to the appliance is great but most companies have the need to get the data off site. With the built-in replication it’s quite easy to replicate the data between two DXi appliances or to setup a many to one replication for remote and branch offices. The DXi replication only sends unique blocks which will reduce the amount of transferred data.
The replication can be easily scheduled using the “Scheduler” which also allows to enable a throttle to avoid bandwidth contention during working hours.
The replication also offers a file based replication mode, which keeps files between two file shares in sync.
Security & Integrity
To protect your data you can enable an AES 128/256 in-flight encryption and/or use Self-Encrypting Drives (SED) with an AES256 bit at-rest encryption. Also built-in is the “Secure shred” feature which will wipe out data by simply overwriting them with zeroes. To ensure data integrity a Healthcheck can be used to verify the health of data as well as metadata.
To separate management, replication and data traffic even the virtual appliance comes with multiple network interfaces which allows to configure them accordingly, including support for VLAN tagging. It would be also possible to create a bond across those interfaces to increase bandwidth if multiple servers send data to the appliance.
VTL & OST
The physical appliances also offer VTL functionality via Fibre Channel. This allows to simulate a couple of tape libraries and drives to integrate the appliance in existing backup infrastructures that depend on tape. With support for the OST protocol backup administrator can offload tasks like the replication of backup data to the appliances without losing the meta-information on the media server.
Combined with the DXi Accent protocol the deduplication can be extended to the media server, so that only unique block will be send to the appliance. Another cool feature is the ability to attach a tape library directly to the DXi appliance to use the Direct to Tape (or Path to Tape) feature to copy the backup data onto real tapes. This way the data doesn’t need to be moved back through the media server.
An advanced reporting feature can help to analyze what’s going and to charge clients based on their actual usage.
Basically those reports can be generated for example on a share or replication basis but it would be nice to have some sort of multi-tenancy support to be able to create logical groups/tenants. I couldn’t find a way to automate those usage reports to get a monthly mail per tenant.
Probably I’ve missed it but a central management for cloud providers to manage own as well as client appliances would be a nice tool to have.
Alternative – LTFS
Even it’s not directly related to the DXi series, it is worth mentioning that customers who are already using a Scalar tape library, Quantum is offering the so called Scalar LTFS appliance. This appliance offers NAS like access to your tape drives which makes it easy to archive lots of data in a comfortable way.
Overall the DXi V1000 made a good impression. It is easy to use and it provides a solid performance even on minimal lab hardware. But no matter how good or sometimes bad a product may is, often it comes down to the pricing. Currently I have no prices to compare vs major competitors like EMC, HP or Dell. However I will definitely consider the DXi next time.