[linux-lvm] Re: [lvm-devel] [ANNOUNCE] LVM reimplementationre ady for beta testing

[Jesus Manuel NAVARRO LOPEZ]

Hi, James:

James Hawtin wrote:

> 
> On Fri, 1 Feb 2002, Heinz J . Mauelshagen wrote:
> 
> 
>>It is quite intersting how many people don't take backups even though
>>almost everybody claims to know that backups are crucial and some of them
>>know that they are still, even though they might have RAID in place.
>>
>>
> 
> I think the reason most people don't do backups is because, hard disk
> drives are really big and really cheap. Tape drives are really expensive,
> media is also expensive and frankly tapes are very small for the cost.
> Effective backup can double the cost of a system and requires time to
> manage it.
> 


Yes.  That's true... as you say, for grandma's PC.  Backups (and all the 
other disaster/recovery plans) are defensive, so they *must* be 
cost-effective solutions.  *If* you really don't care loosing a week's 
data or even all the data, and with low probability you just can go with 
hard-drive backups or even without backups at all... if you *really* 
know that there's not *if* you're going to loose data, but *when*, and 
accept it.


> For the "home" market its just to much. The only system just about


It is too much *work*, not money: five to twelve zip "disks" (100/250MB 
each) is usually more than enough for incremental backups.  Well planned 
you don't need full backups... you don't need full backups for programs 
you already have in another media (like your programs' original CD's) 
you don't need backups for cold-storable data (six month old MP3 you 
just listen from time to time) you just burn a CD from time to time... 
at the end only personal data is *needed* to be backuped and this is 
*usually* able to fit on one/two zips.  The problem is the time and the 
savvyness to plan it (in advance).  The same goes with any other 
insurance system: for most people you just insurance if you're legally 
enforced, or it's the "common" way (like the health care insurance in USA).

...But the other guy was talking about a *professional* environment.


> affordable is DAT tape, DLT blanks are about double the cost for the
> storage ammount. I bought a DDS4 drive for "home" use, 1 week after I got
> it I had my laptop stolen, so it justified its cost pretty fast :-) A 60
> gig hard disk, costing 100 pounds requires 2-3 DSS4 tapes to backup At 15
> pounds each, one round of backups cost 1/3 of the cost of the disk
> multiply that by the number of disks, add in the hassle factor of changing
> tapes. Auto changers are nice, but alot more! For "PC" based systems the
> backup costs are oftain higher than the price of the machine, and thats
> hard for people to justify.
> 


Hard drives are *not* cheaper.  Indeed they're more expensive by far!!!
You seem to consider that a single copy on the same system can be 
considered a backup, but it is not:
*If you don't have incrementals for a variable amount of time you have 
just crap
*If your backup media is around the system to be protected you just have 
crap

So, for HDDs to be a *real* backup solution, you need as many HDDs as 
you would have tapes (say 10 to 20) so you can have, let's say, daily 
incrementals, placed in-house, weekly "bigs" somehow "near", and monthly 
off-site.  Now, tapes are cheaper than disks, so if you need to have the 
same amount (more or less) disks will be more expensive... and, 
remember, that, while statically-placed disks are more confiable than 
tapes, that's not true as soon as you start moving them here and there. 
  Obviously you can go with PCMCIA disks, but they're *a lot* more 
expensive.


> If anyone suggests they use "hard drives" to back up I will scream, cost
> that system just don't scale, and yup you have an old copy but do people
> ever update it? Yes... when they get another hard drive... however before
> that happens they have put the old on back into service because they
> needed a little more space ;-)
> 


This is true too.


> All in all, backup is expensive/slow, my sister/mom/dad ain't going to pay
> that kind of money for home... For Work its slow, fine if your a sysadmin


They're expensive *by definition* (just in the same way any other 
insurance is: it doesn't *produce* anything).  Anyway, probably your 
mom's life doesn't deppend on data on her home PC, so it's fine going 
with no backup at all, or burning a CD from time to time.


> and that your job... If you are a sysadmin you probably don't get to do
> bugets, your manager does, and they don't understand the cost and aways
> want to cut corners to keep costs down, XXX is a "developement" system so
> we don't need to back it up cos its not "production" etc etc. Store all
> your data on the network file server, (which is aways full with p0rn) and
> connected via a doggie network, taping 3 minutes to access the smallest
> file, so people store data on the local machine, and forget to copy it
> back to the network...
> 


Truly enough: idiocy doesn't pay.


> This why people don't have backups in my book.
> 


And I'm with you.

-- 
SALUD,
Jesús
***
jesus_navarro at promofinarsa.es
***