[OSX-Users] Re: opinion: standalone smaill raid array

[m.c. schraefel]

Actaully, no it's not back up alone:

i want a main source for all the data that is used by the network and 
a main media computer.

backup i already do with time capsulte but it's never included the 
media center stuff.

Having raid seemed to offer higher security with primary data; since 
that does mean a duplicate of all the material should one disk fail 
(which i've had happen not only once over time) Some of you suggest 
this is not that case?

A 2T timecapsule for JUST the media center? dunno.

i want discs
lots of discs
but not lots of cables and power supplies.

so i hope that teases out back up and storage a bit. both and with as 
few boxes, caples and especially power supplies as possible.

best
mc



At 23:54 +0000 on 5/1/10, Hugh Glaser wrote:


>Don't know if this is too detailed...
>
>mc wanted backup.
>I am not sure RAID is the cost-effective solution for backup.
>Most of the problems Terry talks about such as the difficulty of migration
>are more for server stuff.
>I use a RAID in my server for TV programmes etc; I have an external disk (or
>two) for general backup. I guess that is a similar configuration to Terry.
>I'm not sure about your bandwidth problems over wifi, as I mostly use
>gigabit round the house.
>I did try using something like GFS on RH a while ago, but even then you end
>up running out of slots on the server, so have to do a full migration (I
>guess this is the Drobo solution, only better packaged).
>
>For backup I use one disk for backup until it is too small; then I put it in
>a box as an old archive and buy a new one. The way the price/Byte ratio
>changes that seems to work.
>
>One important principle here: never confuse backup and storage, or at least
>be very clear about it all.
>In particular if you start putting (just "temporarily" parking!) non-backup
>stuff on the backup medium, you will end up unable to backup even that very
>low-priority stuff (as Terry says).
>
>Migration of backup is incredibly simple (take the old one offline, and give
>it to a friend to look after, and start a new one).
>
>So going more general than backup:
>
>So I sort of do this:
>Important stuff (documents, system, etc): proper backups (usually on
>non-RAID disk), but on two sites, either by backing up at both places or
>moving a backup.
>Stuff I don't want to lose (iTunes, films): backup on one site, including
>old archives.
>Stuff I could lose (TV programmes primarily): RAID storage, no backup.
>
>So for someone starting from scratch setting up a backup facility, I think
>Time Capsule is actually a pretty good solution.
>And if it is not secure enough, then adding an external disk to back up the
>Time Capsule to is pretty cool.
>I don't do this because I bought a server before Time Capsule came out, but
>I suspect it all depends on what the existing configuration is.
>
>Cheers
>hugh
>
>On 05/01/2010 22:36, "Terry R Payne" <trp at ecs.soton.ac.uk> wrote:
>
>>  On 5 Jan 2010, at 20:03, Philip Boulain wrote:
>>
>>>  Terry Payne wrote:
>>>>  Drobo is a propriety RAID system...
>>>
>>>  Dare I ask what the point of RAID in a *home* NAS is? RAID is good to keep
>>>  availability up for things like the ECS servers, but it's hardly a data
>>>  reliability mechanism when both drives are the same age from the same
>>>  manufacturer, likely from the same batch, subjected to the same load
>>>  patterns, mounted in the same physical case, hooked up to the same power
>>>  supply, and controlled by the same software.
>>
>>  The point of a RAID at home, and in particular - Drobo?
>>
>>  Simple!  I was fed up of migrating my iTunes archive from a 100Gb 
>>-> 220Gb ->
>>  500 Gb, to then have a power-supply failure (not disc), which 
>>still scared the
>>  hell out of me.
>>
>>  Drobo gave me an incremental way of upgrading my capacity without the hassle
>>  of migration, and the *bonus* of getting some degree of safety 
>>given a single
>>  disc crash.  Is this the best way of getting protection?  Better 
>>than relying
>>  on a single disc, and when your archive is 1.7Tb (and growing), 
>>getting a disc
>  > for backup that is on average 2-3 times your working data size is can cost!
>>
>>  More to the point - having to buy potentially two new external 
>>discs each time
>>  I migrated started to be way too expensive.  Mebbie I'm taking a 
>>chance right
>>  now in *just* relying on the drobo, but I do have a copy of most of the
>>  valuable content on a separate disc.
>>
>>  Down the line I'll pick up a second Drobo to act as a mirror for my
>>  collection, but all in good time...
>>
>>  So the issue is - do you want expandable storage with some protection, or
>>  fixed storage with mirrored backup?  For the former - Drobo is a 
>>good option,
>>  the latter, Time Machine with a fat disc!
>>
>>>  Hugh's suggestion of a Time Capsule, or the also popular combination of
>>>  putting a big external drive on a Mac Mini, seems more practical to me; no
>>>  proprietary RAID hardware meddling with the disk layout and making it
>>>  unreadable by anything else.
>>
>>  It *all* depends on what you need!  If you are media rich (and 
>>also dynamic),
>>  then be careful with traditional backup systems.  I have an eyetv 
>>box which I
>>  use to record most the content I consume from the TV - this may get edited,
>>  and then exported to an iTunes archive.  If you assume a 1hour 
>>episode of some
>>  series or other is about 2-3Gb, and you record 4-6 hours of this 
>>content, then
>>  12-16Gb per week could be recorded.  If you are faithfully backing 
>>this stuff
>>  up via Time Machine, then that is a lot of data potentially travelling over
>>  Wifi, and then filling up you backup archive (despite you watching 
>>the episode
>>  and deleting).  Best not to back this stuff up... but then what about that
>>  series you didn't get around to watching but downloaded the whole series for
>>  the winter???
>>
>>  A RAID gives me some protection, but without the hassle of finely tuning
>>  backup policies, or having to periodically maintain the backup archives.
>>  Incidentally, I also have a Time Machine archive which backs up 
>>the main disc
>>  activity, but it leaves the media archive to do its own thing.  Hmmm...
>>  different tools for different tasks....!
>>
>>  Look at your requirements and the options - don't just go with one 
>>or t'other
>>  option because of us evangelists, or cynical nay-sayers!
>>
>>  Terry
>>
>>>
>>
>>>
>>>  --
>>>  | Philip Boulain   PhD student | The human race will begin solving its |
>>>  | IAM, ECS, Uni of Southampton | problems  on the day  that it  ceases |
>>>  | http://zepler.net/~lionsphil | taking itself so seriously.-Discordia |
>>
>>
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