[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Recommended tape backup software - tape vs disk



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.


-- 
To UNSUBSCRIBE, email to debian-user-request@lists.debian.org 
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org



Reply to: