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Re: Ultrium LTO-4 File Name Length Limitations

 
blafarm
New Member

Ultrium LTO-4 File Name Length Limitations

Can someone please tell me if HP's Ultrium LTO-4 tape drives have a known file name length limitation.

I need to archive thousands of files that have rather long names.

Thanks for your assistance.
4 REPLIES 4
thomasr
Respected Contributor

Re: Ultrium LTO-4 File Name Length Limitations

There's nothing I know of that's a limitation in the drive hardware. There might be limitations in the backup application, which you'll have to pursue with the backup application vendor... but unless your filenames are of truly epic length, I suspect that any enterprise backup application will be able to handle them.

I will warn you that long file names and deeply nested directories will have negative effects on backup performance. If this does turn out to be an issue for you, consider either:
1) use disk as the initial backup target, which will create a single file optimized for copy to tape. The disk target could be created and managed by the backup application or could be a virtual tape library such as HP's D2D 2502i Backup System.
Or,
2) perform an image backup as opposed to a file backup. This may cause significantly longer restores, but the backup will be much faster.
--
Liberty breeds responsibility; Government breeds dependence
blafarm
New Member

Re: Ultrium LTO-4 File Name Length Limitations

thomasr,

Thank you very much for your response.

The reason for my inquiry is that we are finally migrating away from archival quality DVD-R discs -- which routinely truncated our lengthy files names. Being new to LTO, I was trying to determine if file name length issues were also a consideration. Fortunately, our file nesting depth is limited to two or three directory levels.

I'm not yet familiar with HP's Data Protector Express Single Server Edition software -- which I believe ships with the StorageWorks 1760 LTO-4 Ultrium Drives, but I believe that both of your suggestions include creating a single intermediate file in order to overcome potential problems.

Your first suggestion seems to be to "target" the tape archive file -- to a hard drive first. Do you happen to know if HP's Express software can do that without file size limitation? I read about a 36 GB D2D limitation on this page (see text highlighted in yellow)...

http://awurl.com/8oNVtg4zR

...but I don't know if it applies to the working methodology of your suggestion.

Your second suggestion seems to imply something along the lines of a Norton "Ghost"-type image intermediate file. Is that correct? And is HP's software capable of that "imaging" -- or would I have to use a separate application?
And, if so, what might you suggest? My reason for asking is that I believe Ghost only images volumes -- not folders -- and while I could use the subst command to convert a folder into a virtual volume -- I'd love a more straightforward process.

Thanks again thomasr -- I really appreciate your assistance.


thomasr
Respected Contributor

Re: Ultrium LTO-4 File Name Length Limitations

> The reason for my inquiry is that we are
> finally migrating away from archival
> quality DVD-R discs -- which routinely
> truncated our lengthy files names.

Yes, that is a problem with the CD/DVD file system. Since tape is a block-oriented device, it doesn't have a file system.

> I'm not yet familiar with HP's Data
> Protector Express Single Server Edition
> software -- which I believe ships with the
> StorageWorks 1760 LTO-4 Ultrium Drives,
> but I believe that both of your
> suggestions include creating a single
> intermediate file in order to overcome
> potential problems.

Just the first one.

> Your first suggestion seems to be to
> "target" the tape archive file -- to a
> hard drive first. Do you happen to know if
> HP's Express software can do that without
> file size limitation? I read about a 36 GB
> D2D limitation on this page (see text
> highlighted in yellow)...

> http://awurl.com/8oNVtg4zR

> ...but I don't know if it applies to the
> working methodology of your suggestion.

Yes -- I wasn't aware of the size imitation in the SSE... sorry; this will obviously not work well if your data is larger than 35GB (without the upgrade).

Well, IF you run in to performance problems, and IF your budget is reeeeely tight, you could probably create a backup job to disk of just your most problematic files, up to 30GB, do the rest direct to tape... somewhat of a kluge. But don't try that unless you know you have a performance problem.

> Your second suggestion seems to imply
> something along the lines of a Norton
> "Ghost"-type image intermediate file. Is
> that correct? And is HP's software capable
> of that "imaging" -- or would I have to
> use a separate application?

No, not at all. Most all backup programs (and I don't have Data Protector Express handy to verify, sorry!) can perform an "image" backup -- block by block of the disk, instead of file-by-file. This is usually a much higher performance option, since you don't have all the head movement to read directories or span fragments. If Data Protector Express can do it, it will be your fastest backup... but restores could be significantly longer, so don't use an image backup unless you know that performance is a problem... and even then, a D2D2T (disk-to-disk-to-tape) as above would probably be better.
--
Liberty breeds responsibility; Government breeds dependence
blafarm
New Member

Re: Ultrium LTO-4 File Name Length Limitations

Thanks again very much.

Very useful information.

I guess I wait until I get the software to determined its necessity and limitations.

Cheers