Backup to disk, what to chose DAS or SAN?

[pfviv]

Hi.

I am wondering what you think is the best solution for new backup to disk.
We have to day 7 TSM servers an all have its own disks (DAS) connected to the server (Primary backuppool)
We are locking at DAS for etch server or a SAN for all servers.
Are someone running SAN with "backup to disk" with multiple TSM servers?

Ivan

Sorry for my terrible English

[Trident]

Hi,

Everyone has a solution. This is what I have:

TSM Server with DAS for DB/LOG + 25x600Gb for Primary Backup + IBM DCS3700(120x2Tb drives) for Secondary Backup

The DAS is on a 6G SAS shelf (dedicated controller)
The DB/LOG is on a seperate controller on a seperate DAS

IBM SAN (actually 2 san and 2 shelfs) is shared between 3 TSM servers (More will be added)


Data migration path is Client-Primary(No space limit)-Secondary (Smaller than 40Gb)-Tape(Final stop)

[drs]

Hi,

Why do you need to add to or change your disks? Do you need more capacity, or do you have a performance issue? If it's just capacity then I suggest you swap out your current disks for larger disks in the existing setup if that's an option that you can use.

As far as SAN's for disk based backup, you will need a SAN with the most I/O per second to minimise the latency. You also need as many HBA's to match the throughput that the SAN gives you, otherwise you will not use the available bandwidth, and remember that the SAN bandwidth will be shared by your 7 TSM servers. You will need to tune your OS for best performance and data integrity. This is a complex subject so you should seek expert help from a storage vendor or storage consultant in order to implement it. As a quick answer on the SAN choices, I personally would use EMC Symmetrix VMAX if you can afford it, then IBM DS8000, or for small scale implementations the IBM DS5300. Go for SAS / SATA disks and avoid fibre channel due to the FC bus loop limitations.

[pfviv]

Hi

Tanks for the answers. Some of our server's and DAS solution is soon out of service so we have to buy some new backup to disk and double our capacity at the same time.

This is useful information so if any other have some input please replay.

Ivan