Re: Recommended tape backup software - tape vs disk
You and I must think on different scales...
30 days worth of the 155GB database that I manage, plus
the 40GB of flat files == 5.8TB
30 days worth of the 80GB database that I manage, plus
the 20GB of flat files == 2.4TB
30 days of the 1.5TB disk space that my co-worker manages
plus 200GB of flat files == 57TB.
That's 65.5GB of storage, or 546 120GB ATA disks. The
cabinets, controllers & power supplies needed to run all
those disks is _really_ expensive. (If you want them to
be RAID5 secure, add, oh, 15% more disks, so that's 628
spindles!!)
Last, but _certainly_ not least:
If the machine gets destroyed (fire, etc), there goes a
huge business. Can't happen? I managed an 80GB OLTP
database in the WTC...
There is NO WAY I'd allow an important production system
without off-site tape storage.
On Sun, 2002-05-19 at 19:24, Alvin Oga wrote:
>
> hi ya ron
>
> > [snip]
> > > - tons of problems with tapes for "large amount of data"...
> >
> > You get what you pay for. At work, we use DLTs, and _never_
> > have problems, as long as we run the cleaning tape weekly.
> > Part of the reason is that DLT drives are made well, and another
> > reason is that these drives have hardware ECC.
>
> <flame suit on>
> tapes are less reliable than disks...
> </flame suit off>
>
> and i dont ever wanna remove tapes... some moron always forgets
> to change the tape etc... or clean the head later
>
> > > - i prefer disks for backups... fast, easy, cheap and
> > > (offline) live backups
> >
> > On a production box of any size, that is totally impractical.
> > Tapes are, by their nature, removable, whereas, IDE disks are
> > not. SCSI disks are, but a 72GB disk is _way_ expensive.
> > So, on a box the size we use at work, in order to have a month
> > of backups, you'd need 90 72GB SCSI disks. No fscking way!!
> > 90 DLT4 tapes, on the other hand, is expensive, but affordable.
>
> precisely why tapes are impractical ....
> - but there are tons of data on existing disks ...
>
>
> 160GB ide disks is $150-$200 range... cheap...
> - 1Terabyte of backup in one 1u chassis.. no problem...
> and i do compressed backups of up to 3 or 6 months... dpeending
> on diskspace they willing ot buy and user data
>
> IDE disks are ideal for backups... its already up and running
> and is live... within a few minute if one does 1:1 mirror backups...
> or goes live as soon as tar uncompresses on disks ...
> ( no fussing on where is the tape.. and which tape...
>
> - lost data need to be recovered and online within the hour...
>
> - realtime transaction based data is a separate issue...
> ( and they have the $$$ too ..hopefully ...
--
+---------------------------------------------------------+
| Ron Johnson, Jr. Home: ron.l.johnson@cox.net |
| Jefferson, LA USA http://ronandheather.dhs.org:81 |
| |
| "I have created a government of whirled peas..." |
| Maharishi Mahesh Yogi, 12-May-2002, |
! CNN, Larry King Live |
+---------------------------------------------------------+
--
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org
Reply to: