I know no one answered my last post yet, but I have another question...What are the pros and cons of backing up to disk using NetBackup or native sql backups? Is any one better than the other? I would think that sql backups are more reliable and easier to use- is this correct?
i use Veritas 5 Netbackup for a bunch of servers. Disk is still pretty expensive if you need months or years of backups. We keep 6 months of backups onsite, send out one of the backups every month offsite and routinely restore production db's to QA and other testing. Sometimes we had to restore last month's backup because we needed some data into current production like when an archive script goes haywire and deletes data without archiving it first.
We have a disk based backup system for NT and MS Exchange from Evault but it compresses the data and has other goodies to minimize disk space. Avamar is good too, but expensive.
With tape we have a lot of backups on different tapes. With disk it is possible that you can have your RAID array die on you and lose all your backups. HP's new 300GB drives, we have had half of ours go bad in the last year. Once we had 2 die in the same RAID array in one week. Luckily HP send replacements out next day air and we rebuilt the array after the first failure and just in time for the second. Otherwise it would have been a 500GB archive database down the drain.
has anyone poseted a reply on this sbject.
I am interested on how much diskspace I will need to backup SQL databases via the netbackup agent (and any alternitives that may be better like using flatfile instead)
Probably the single most important difference between disk & tape backup is the time to restore. Tape backups take "forever" compared to a restore from disk - and that's if you just happen to have the tape available onsite - worst case you might be looking at several hours to get the tape back onsite before you can even begin your restore.
I typically advocate a dump & sweep approach to database backups with a nominal retention on disk and longer term retention on tape. Reality is that most database backups are useless beyond a couple of days - would you want to have to tell the business that they have to redo several days of transactions? Me neither.
The biggest problem with most "enterprise" backup systems like Veritas is that they are only capable of taking backups of the database each night (if you're lucky) and frequently only able to take a full backup of "everything" over the weekend which is just fine if you're backing up a database that is only updated once a month but just doesn't cut it when you need to be able to recover to within a shorter timeframe (e.g. 10 minutes).
SQL->DISK->TAPE is hardly a "best practice". It is merely one way of doing it. It can be difficult to manage and easily becomes unmanageable when there are simply too many databases and/or servers to support. It works great in small deployments and that's what I will often choose for clients if it is the right fit. It can also give you more precise control over timing, if the business need is there, so it can be useful in large envioronments as well.
NetBackup is expensive, but you get what you pay for. It is an excellent tool for SQL backups. It's difficult to get set up correctly, but it works flawlessly once it is ready. It also has the benefit of keeping all of your enterprise backups in one place, which may very well be a requirement dictated by people whose names are on the front of the building.
So, it depends. Go with what is best for your situation.
A few other points in favour of backing up to disk ...
Everywhere I've worked as a DBA, doing backups this way neatly mirrors the departmental structure in that the DBA manages the backups to disk and the Windows Server guys manage the backups to off-line media. i.e. they don't fiddle with my databases and I don't go near their tape drives !
For most network backup solutions, you will need to buy an additional item of licenced software in order to back up your SQL Server databases directly. Backing up first to disk means this is not necessary. If you have a lot of servers this can be a big saving.
It can be difficult managing your SQL Agent schedule when you have backups taking place outside of that schedule at a time which may vary from day to day. The network backup software optimises the schedule to keep the tape drives loaded appropriately and knows nothing about your servers batch workload. If you back up to disk first this dependancy is broken.
The only good reason (IMHO) to back up your databases directly with a network backup solution is if you have very large databases and the cost of disk space is an issue. I'm forced down this route with a few servers but make sure if you go this way that you carry out regular test restores (you should anyway but in this case it becomes even more important because there are more potential points of failure).
Phil's "very large database" are a great example of why compression products like SQL Safe, SQL Backup & Litespeed are usually a great addition to your toolset - they will usually pay for themselves pretty darn quickly as the compressed backups take up anywhere from 35 - 90% less space... I don't know if any of those products will work in conjunction with Netbackup or other backup software to backup direct to tape? I do know that the last time I priced Idera's product it was actually cheaper on a per machine basis than the corresponding Netbackup SQL Server agent.