Wednesday, 21 September 2011

Designing Backup Solutions to Compliment Veeam Backup

Design requirements

1) The backups must be quick and efficient with little impact on the production virtual environment.
2) Backups must not be saved to the same production SAN that contains the data being backed up
3) There must be provision for backups to be off site.
4) Restores must be quick and efficient.
5) (Optional) there must be provision for offline backups.

Component Parts of a Backup Solution

1) Veeam Backup Server

Options:

i: Physical Windows Server

→ If the storage infrastructure is pure Fibre Channel (no option for iSCSI) then Veeam Backup Server will need a FC HBA for Direct SAN access
→ If the storage infrastructure is iSCSI (or FC with iSCSI functionality,) will need NIC ports patched into the iSCSI SAN for Direct SAN access
→ The Veeam Backup Server needs to located sufficiently close to the virtual infrastructure, and with sufficient bandwidth, to support efficient Direct SAN access backup
→ Easy support for many different external backup devices
*The backup over networking mode is not recommended for performance reasons
*Veeam Backup is not supported on Windows Storage Server

ii: Virtual Windows Server

→ If the storage environment is predominantly NFS, this is ideal since Virtual Appliance mode can be leveraged to avoid having to use the slower performance backup over network option
→ Works well with iSCSI SANs using Direct SAN access backup mode
→ (Small advantage) If you have more than one Veeam Backup Server, you can use one Veeam Backup Server to backup the other's system and program files drive
*A Veeam Backup Server cannot backup itself
*Veeam Backup is licensed on host sockets, there is no limit to the number of Veeam Backup Servers you can create

Comment:

Much of the choice here comes down to personal preference and/or cost. It is often useful/desireable to have one physical Windows server alongside the VM host servers, and this one physical Windows server can be the Veeam Backup Server.

2) Backup Storage and Provision for Off-Site Backup

Some options:

i: Physical server with local or direct attached storage
either replicate backups to a similar server (software replication)
and/or backup to removable hard disk to be taken off site

ii: iSCSI/FC SAN (not the same SAN data is being backed up from)
either storage/software level replication of backups to a DR site
and/or backup to removable hard disk to be taken off site

iii: iSCSI/CIFS/NFS NAS
either storage/software level replication of backups to a DR site
and/or backup to removable hard disk to be taken off site

iv: Post-process deduplication (RECOMMENDED)
backup directly to a post process dedupe appliance and replicate to a partner dedupe appliance (the partner dedupe appliance could be a service provider offering BaaS.)
and backup to removable hard disk if additional offline backup is required

v: In-line deduplication
backup to storage local to the Veeam Backup Server then copy across to an in-line dedupe appliance, replicated to a partner dedupe appliance
and backup to removable hard disk if additional offline backup is required
*Depending on the desired speed, there is no reason why cannot backup directly to an in-line dedupe appliance, this will be slower than backup to post-process dedupe appliance

Comment:

Much of the choice here will come down to personal preference and/or cost. Deduplication is recommended for maximizing use of storage and minimizing network traffic when replicating backups. Post-process deduplication is recommended over in-line dedupe for speed of backup to disk.

Argument against using tape with Veeam Backup

Storing Veeam backup files (vbk's, vrb's, vib's) on tape does not make for an elegant solution. Veeam backup cannot back up directly to tape.

Even so, writing the vbk and vrb/vib sets to tape post backup is not a problem with other tools, the problem is recovery, and to recover from tape a Veeam Backup Server first needs available disk space on which to pull the data off tape prior to commencing a restore to the virtual infrastructure. A restore of a 1TB vbk and vrb/vib set may take 5 hours. Also, testing of Veeam backups written to tape is a similar problem, it requires the time to recover to disk first before even knowing if the file is usable and free from corruption.

It could be argued that tape is only used for cheap archival. This argument does not completely stack up though. There is no point storing backups if there is strong reluctance from the IT Support Team to use them for future restores because it is known that the recovery process is long and time consuming. Also, the tapes need to be tested and this takes additional time over disk-based solutions. Then when it comes to restore from tape, this takes additional time over a restore from disk. And when time is money....

A much better solution is to keep backups on disk, which allows for instant recovery and easy testing of backups. This would mean either keeping all the required backups on disk - either cheap storage, or more expensive in the short-term but – if achieving high levels of de-duplication – cheaper in the long run, then file deduplication storage; and the backups can be replicated off site (which is where dedupe devices come into their own because only deduped changes are replicated) and/or removable hard disk technology can be utilized.

Comment:

Much of the choice regarding tape or disk comes down to personal preference and/or cost – especially if there has already been considerable investment in existing tape backup infrastructure...

Final Comment

There are many permutations to consider when designing a backup solution to compliment Veeam Backup. I most certainly will have missed out some ideas and solutions, and this is not intentional. On purpose I have avoided mentioning vendor names and products (except for Veeam and Windows.)

Please feel free to leave any comment.

Cheers!

Credit to my colleague Alfredo for introducing me to many of the ideas and concepts in this post.

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