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Re: IDE DAT Drive?



On 2000-11-23 09:20, Robert Davies wrote:

> Do you REALLY have 300G of things that need to be backed up?
> If so the solution is a DLT robot.  But most people who think that they
have
>that much data to backup aren't doing things effectively.

I sure do, I wish I hadn't and it's growing 1GB a week.  Unfortunately the
archives get updated,
so I can't even freeze parts of it, it all has to be online 24/7.

Russel, it wasn't me with the backup problem, though of course I have many,
but I've not needed to call in Curtis Preston yet...  yet anyway ;)

> Don't backup news spools!!!
> Don't backup email as it takes too long to backup and changes too fast.

Add squid cache's and the like to that.

>>> Oh, don't backup user's mail directories.  They change so much that a
>>>backup that's more than 1 day old is probably useless.
>>
>>This may upset users when they loose days worth of email, that they were
>>unable to download,
>>or had left on the server, because they were travelling.
>
>If you have a serious failure then users will be upset regardless.  If you
>use a mail server such as Netscape's mail server then due to it's databases
>you would have to restore while the server is offline.  Recently I was
>working for a large ISP (>750K users) and I estimated that it would take 10
>days to complete a backup of email.  If email takes 10 days to restore then
>you are better to dump it.  If it takes 5 days to restore then it's
probably
>best dumped.  How fast should a restore be to be worth-while?

In that case yes, but I find it scary that they have all their eggs in one
basket.  Prefer a divide and conquer approach, have enough problems with
Oracle DBs where it's all or nothing, most times.

>I had a big discussion on this topic with my former colleagues.  They
>couldn't understand why backing up a mail spool (tens of millions of small
>files) would be slower than backing up a web server (tens of thousands of
>mall files, a few really big log files, and the OS).

If you've that many files in a mail spool then you have problems.

> would recommend SCSI for this type of thing.  Setting up tape drives is
> oblematic enough without going through the issues of companies that
produce
> w quality versions of the parts for IDE.  Also compared to the cost of
> tapes the cost of a SCSI controller is nothing.

Yep, though Matt could comfort himself with the though that the Onstream IDE
has been used successfully and discussed on the Linux kernel mailing list.

Rob



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