About basic disk staging using SAN storage

[RLeon]

Windows 2008 R2
Netbackup 7.1.0.2

Hi all,

We have a media server setup to backup its E: drive (5TB) to its F: drive (10TB, Nbu basic disk staging). Backups will then be relocated to the Tape Library from the F: drive, according to a staging schedule.

The E: drive and the F: drive are both luns from the same SAN storage appliance connected via the media server's fiber hba. The tape library is also connected via the same fiber hba.

The data path for a backup goes:

1. During a backup, data is first transferred from the SAN to the media server (the E: data).
2. Then it is written directly back to the SAN (to the F: staging drive)
3. In a relocation, the same data is transferred back to the media server again from SAN. (The F: data)
4. Then, it is written right back via the SAN to the Tape Library.

So for each backup, the same data traverse the SAN four times.

Is this a typical setup? I want to know because it doesn't seem very efficient.

Is there a best practice for what we are trying to do here?

Thanks for your help!

RLeon

[Dan33]

Is there a reason you don't backup directly to Tape from E:\ ?

I have the clients backup to staging disks on my media server, then it gets duplicated to Tape. I don't backup one Media Server drive to another, then to tape.

Unless there is a good reason it seems like a waste of resources, when you could be backing up other things to the staging disk.

[RLeon]

From that media server's perspective, Both E: and F: are local disks.

E: is where the source data resides.

F: is not used for anything else other than as a staging storage unit in Netbackup. This staging storage unit does not serve any other server other than the media server itself. In other words, no backup data ever travels through the LAN from another server to this staging storage unit.

The primary reason we don't backup directly from E: to tape is because we want to speed up restores by utilizing the staging feature. We do quite a lot of restores so we think this is justified. (Restoring from tape is much slower, especially when you do many restores everyday.)

I guess I could have have explained our config better by saying that this media server only backs up itself. It doesn't back up anyone else's data.

RLeon

[Dan33]

You could create a schedule to do multiple copies. One can go to Tape and the other to your staging disk.

You can set different retention periods for each copy and it will happen at the same time.

You would want to disable your staging schedule as you will already have the data on Tape.

[RLeon]

Your suggestion sounds logical, but I am worried that it may stress our SAN in the following way:

1. During a backup, data is first transferred from the SAN to the media server (the E: data).
2. Then it is written directly back to the SAN (to the F: staging drive)
3. At the same time 2. is happening, another data stream is also writing the same data from the media server to Tape, via SAN

So there will be three data streams on the SAN at the same time for every backup.

Also, your suggestion vs Netbackup built-in basic disk staging.... They both seem to achieve similar things (apart from the different retentions using your solution). So in general, when should I use which?

Thanks for your help!

RLeon

[Nicolai]

The basic staging disk feature does not allow to set diffrent retension periods for each copy. To do that you need the Advanced Disk feature and Storage Lifecycle Policy's.

[RLeon]

Hi Nicolai,

Thanks for the info. That is what I said when I reply to Dan33 (starting from the "apart from" part)

Can you also shed some light on my main query please?

Thanks!

RLeon