hi ya ron
On 19 May 2002, Ron Johnson wrote:
> You and I must think on different scales...
think its similar scales..
- different ways to skin the cat...
- a tape is 40 - 80GB.... same as disks ... nowdays disks is
always slightly higher capacity....
- there was a time when a single tape had more capacity than
a single disk... and better price for disk$$$/MB vs tape$$$/MB
- in the old days... whan disks were expensive per GByte
and tapes were comparably cheaper.... tapes would be better
- any argument for number of disks is equally applicable
to number of tapes ....
- tape library vs raid ...
( same issue here too )
- we had/have a bunch of Exabyte Magnum(?) drives ( $8K each )
a few years ago ... when 20GB disks was just coming out...
but the tqpes was too slow... even with tar + buffer ...
tape cant keep up for backing up xxxGB of data
- went to disks for backup and never looked back since...
those tapes was good for 80GB or so...
and we had 40 users at 20GB each...
- i require 3 independent sources of backups.... 2 is minimum....
------------------------------------------------
-
- offsite is not important as much as in different buildings
-
- if a build burns down in a fire... that's what monthly
backup is for.... take the disk and store it some place else ...
--- if the disks is raid5'd ... give one disk
--- to each of the CEO/CFO/CTO/foo/bar and no one user
--- has all the data... no way for stealing corp secrets
- majority of stufff i do is across the ocean ...
-
- can't go around changing tapes... :-)
- and even if the tapes was in my office... i still wont use it
- as we all step away on weeekends and holidays and sick etc...
-
- i say a tape based backup fails the day somebody forgot
- to change the tape... you lost yesterdays data
-
- out here... 50-100GB of data to play with per day per user ...
- most of the generated outputs is not backed up
since its easily regenerated by the spice programs...
- when doing full chip layouts... we can get into 10's Terabytes
of data... most of which i claim is worthless....
and constantly changing .. no pointto backup other than for "archive"
and the lawyers to have a running history...
- what cannot be lost is the schematics and simulation parameters
all that (incremental) data is saved over 3-6 month periods...
- each user pc has about 160GB of disks
- wondering how to backup data/service on an OC3 line now...
( next project ...
have fun "backing it up"...
c ya
alvin
> 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.
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