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Looking for a backup solution?

We have a Network Appliance F820 and we are going to use it as a file server for both Unix and Windows (Win98,...

NT 4.0) clients. We are planning to use the multi-protocol (NFS and CIFS) capability extensively since we have many PC and Unix clients. I have looked into backup methods for this system, and it looks like there are three methods.

1. Buy a tape library of some type and connect it to a SCSI port on the F820, a small computer to run NDMP compliant software and backup software package that supports NDMP. The computer and backup software would be used to manage the tape library and its robotics, and the data that is backed up from the NAS to the tape library. The main data path would be from the NAS, through its SCSI port, and into the tape library. I checked with tape library vendors and software vendors (Syncsort, Veritas, Tivoli) and the software option is about $28K to $45K, plus about $25K to $30K for the tape library and blank tapes, and about $2k for a PC. That is way out of our budget.

2. Connect a tape stacker unit to a SCSI port on the F820, and use the NetApp F820 internal na_dump and na_restore commands. This will require a tape stacker unit that can be placed in a mode that allows the stacker unit to automatically sequence through some or all of the tapes that are loaded into it.

3. Use a specific computer as a "backup client", give it access rights to access all file systems on the NAS, mount all of the file systems on the NAS, and use an existing backup system (software, server and tape library) to back up the NAS as mounted files. This method is being considered because the current backup system cannot support NDMP.

My questions are:

a. The NDMP method is suppose to be the best but is there tape library and backup software combinations that can provide this capability for no more than $20k to $30K total?

b. What problems will we encounter by using method #2 or method #3 instead of using an NDMP compliant scheme?

c. If we need to do some type of major restore from tape with method #2 or #3, what kind of information will not be backed up, like NT or Unix file attributes, specific filer configuration information, etc.?

d. Is there a way to use method #3 (network mounting the filer and using the backup software on a Unix or NT 4.0 system to mount the filer and backup the files on the filer), along with some type of limited backup on the filer to a single tape drive (e.g. 8 mm tape or 4 mm DAT) on the filer, using command line options of na_dump and na_restore to transfer backup specific filer configurations to tape?

e. If we use method #2, can you provide the names and model numbers of tape stacker units that provide this "automatic tape sequencing" (i.e. not robotic commands) so that the na_dump and na_restore commands can be used?

Thank you for any help.

In answer to your questions:

a. There's probably not a solution for less money given what you are trying to accomplish. You could check the "no-name" brand vendors but be careful about support, quality, etc.

b. That scheme has operational challenges and the potential for problems is very high. It will require a great deal of operator babysitting and can be very frustrating. It might lead to not having the data backed up when you really need it.

c. The answer to solution three depends on the software that you use. Most will indeed backup all the attributes and do what you desire. For number two, I'm not sure. You'll have to ask NetApp but I doubt that you?ll get the filesystem-specific control information.

d. I can't understand the purpose of this unless you're trying to save the cost of buying the backup software. If that's the case, you need to reexamine that decision. It's money well spent.

e. No. That's not something I track. You'll need to look at each manufacturer.

Randy Kerns
Evaluator Group, Inc.

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This was last published in December 2001

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