Skip site navigation (1)Skip section navigation (2)
Date:      01 Aug 1998 12:53:18 +0200
From:      Benedikt Stockebrand <benedikt@devnull.ruhr.de>
To:        Andrew Bromage <bromage@queens.unimelb.edu.au>
Cc:        freebsd-stable@FreeBSD.ORG
Subject:   Re: CD writers as a backup medium
Message-ID:  <874svxm0rl.fsf@devnull.ruhr.de>
In-Reply-To: Andrew Bromage's message of "Sat, 1 Aug 1998 18:04:01 %2B1000"
References:  <199807311940.MAA11663@hub.freebsd.org> <199808010247.WAA05287@pobox.ids.net> <19980801180401.24027@queens.unimelb.edu.au>

next in thread | previous in thread | raw e-mail | index | archive | help
Andrew Bromage <bromage@queens.unimelb.edu.au> writes:

> Just wondered if anyone had thoughts on using a CD writer with
> FreeBSD-stable as a backup medium.

Writing a CD-ROM on a machine that is doing other things as well is
bound to cause trouble.  Your backups will be plain unreliable.

>  Does the lack of hard real-timeness matter? 

Not as long as the machine isn't too busy.  Which you can't guarantee
on an ordinary server.

> Like, if some other process starts thrashing, will my CD be ruined?  

Exactly.  But there are events short of actual thrashing that may ruin
it already.  Like a couple processes too many doing disk I/O, e.g.
makewhatis or locate.updatedb.

> Is the support for some writers better than others?

The slower they are the better are your chances that things will work
out in spite of other processes.  Maybe the writers themselves differ
in their cache size, too.

>  Should I just stick with tape?  

Yes, except maybe if you've got a dedicated "Toaster" machine and make
sure it's only doing one thing at a time.  Or shut down your server
and do the writing in single user mode or something similar.

Anyway, tapes are the better choice.

> Sharing of experiences would be greatly appreciated.

A DDS-2 streamer is about as expensive in hardware as a CD-Writer,
cheaper in media (considering their capacity), faster, requiring less
media changes and just more reliable.  That is, unless you re-use the
tapes too often.

If you can afford to spend some money you may even consider a small
DLT drive.  A DLT 4000 is no more expensive than a dedicated "toaster"
box.  The media are expensive so you have to recycle them more often
(but they'll last more cycles than a DDS tape).  If you want to build
up an archive of backups they're probably no choice, really.
Otherwise go for it if possible.


So long,

   Ben
 
-- 
Ben(edikt)? Stockebrand    Un*x SA
My name and email address are not to be added to any list used for advertising
purposes.  Any sender of unsolicited advertisement e-mail to this address im-
plicitly agrees to pay a DM 500 fee to the recipient for proofreading services.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?874svxm0rl.fsf>