Subject: Re: Questions regarding dump
To: None <>
From: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
List: current-users
Date: 07/21/2000 08:18:45
At 23:25 Uhr +0200 19.7.2000, Matthew Jacob wrote:
>> What the hell are they smoking?  Is there another REMOVABLE medium which
>> we should be using instead?
>No, not yet. The mismatch between growth in disk storage and the density of
>tape storage is really bad now. Everyone is now getting toward the point where
>very large sites have been for a while- you don't really back up (reasonably)
>a 20 TB system-if, using restore, you had to reload all 2TB, you'd be down for

Again, Matthew, can you please state your preconditions and check whether
they are relevant in any way for the average setup where a NetBSD server
would get used?

>You make sure your metadata is backed up offsite (this is usually still
>a tape backup possibilty) and do mirroring and RAID stuff for the datasets and
>hope for the best.

What qualifies as "metadata" in this context?

Seems you are happily ignoring the gap between high availability (RAID
here) and long-term archiving (on optical storage, maybe). When you punt
tape storage, where do you store a backup for that document someone deleted
in error three days ago?

Mirroring and RAIDs do not protect you from human failure in any way. Your
RAID will happily mirror your virus-infected M$ Office documents.

>> I don't say it's 'all bad' as much as I say 'it does not fit my criteria of
>> usability'.  Sorry, but with all the other free stuff out there, I don't
>> see it as unreasonable that I should be able to back up my system for free.
>I have mixed feelings about this. On the one hand, I totally agree with you.
>On the other hand, having spent years in the backup space, I have a sort of
>italian-accented little subvocalized thought that keeps muttering into my
>inner ear, "What is dis? Why do they so wanna disrespect their vital data so
>much? It ain' right...."....

"Why do we use NetBSD, instead of Solaris or AIX (or NT)?"

Am I the only one who does not have TBytes of data to store (and > 5k USD
to shell out for Legato =8> )?

>To a first approximation, dump does work reasonably well for small backup
>requirements (and even smaller restore requirements). I myself don't use it
>that much- I haven't for years (. This is because *I'm* comfortable with
>NetWorker which allows me, on a day to day basis, to recover *this* file which
>I've just mistakenly removed (instead of having to do the whole restore -i
>goop, find the tape, load it in, etc..).

Again, your "small requirements" might be average for others.

>There is nothing in my suggesting that NDMP might be useful which would
>require any hardware changes.

Indeed, NDMP _does_ look interesting (you might even be able to run
Amanda's concepts over it), but it does look complex, too. In NetBSD 2.0,
maybe... And in the meantime, _please_ let's keep dump/restore in a working

>This isn't a 'backup hardware' issue. You have the hardware you have. It's not
>even close to impedance matched to the 18GB disks that you can buy at
>clearance prices on the Web now (which is why tape backup, per se, is somehwat
>problematic now even for the brand new tape drives you can buy- I mean the
>default storage size for disks that you can buy soon will require you to have
>a changer for all but *the* most expensive tape media). But working with a
>piece of software that was designed after 1978 might assist in making the
>transition for your usage of the 8200 into a more open sourced network backup
>model - or may not.

Amanda backs up 30+ GB of disk storage with a 4GB Tandberg SLR5 streamer
for me. Only requirement is that partition sizes have to be below 4GB
because level 0 dumps have to fit on one tape. But 50GB QIC drives are
readily available,. not to mention DLT or AIT drives.


"It's never straight up and down"     (DEVO)