Subject: Re: RAID In general (Re: Hot Swappable IDE Kits)
To: Greywolf <greywolf@starwolf.com>
From: Wojciech Puchar <wojtek@tensor.3miasto.net>
List: current-users
Date: 04/18/2003 08:00:23
>
> (me)> ...much about speed and data size omitted...
>
> WP> but not with DAT media or CD-RW
>
> You obviously missed the speed/size thing.

speed is not a problem as it works in background and doesn't lock the
system.

CD-RW isn't that slow now (up to 24x CD-RW)

>
> Several points:
>
> * DDS-4 drives still run a hefty chunk of change, and DDS-4 media aren't
>   that cheap.  And the drives are still slow.  Last I checked, drives were
>   $500 or more, and media is $25 each, and you get 20GB on a tape.

no problem to buy for $15 in Poland. anyway not THAT cheap.

>   Initial cost to back up 100GB: $625 plus applicable taxes.  Subsequent
>   cost to back up 100GB: $125 + applicable taxes.  Speed: slow.  Setup
>   considerations: low.
>
> * CD-RW is slow, and you still only get 800MB/CD.  Does anyone out there
>   have the courage to run 'dump 0usdf 16000 64000 - / | cdrecord [args]'

do you have example how to do multivolume backups with command?

i have problems with dump/cdrecord and file fifos to do it.

>   and not worry about creating a coaster?  Or would one have to pre-split
>   the backups into 800MB chunks and iso them before cd-recording them?
>   This would defeat the purpose entirely.  Cost for a burner: $60.
>   100GB/0.8GB = 125 CD-RW.  Price per CD-RW: $1.  Initial cost: $185 + tax.
>   Subsequent cost: $125 + tax.  Speed on writing: slow.  Speed on reading:
>   Acceptable.  Setup considerations: high.
>
> * HD might run a little more.  I've seen 100GB drives for $125 on sale,
>   maybe $150 otherwise.  (IDE, obviously, since that's what we're discussing).

for SCSI-only systems SCSI-to-IDE bridge for 60-70$ could be bought, which
give possibility to hot-plug/unplug (SCSI devices can be rescaned and can
be hot plugged)

>   Initial cost: $150 + tax.  Subsequent cost: $150 + tax, probably less
>   as HD prices go down.  Speed on reading and writing: fast.  Setup
>   considerations: low.
>
> This all misses the point that hot-swappable IDE would STILL be really nice
> to have, for a variety of reasons.

yes it is.

i'm just worried about how long hard disk will survive being often turned
on/off, changed temperatures etc..

hard drives last very long if used constantly but don't like rapid
changes.

if long - it's worth of using. for example SCSI-only system with fast
(and expensive) disks, + SCSI hot-plug rack+SCSI-to-IDE converter and
couple of cheapest low end IDE drives as backup