Re: OT: Kaliedascape Wannabe!!

["simon.millward" <simon.millward@xxxxxxxxxxx>]

Many thanks for the prompt response!! I am in the process of buying
a=20
16array controller card and so would like a case that takes more HDD.=20
I thank you for answering the main points.

Can I 'Cluster' several servers like you can with disks?

--- In ukha_d@xxxxxxx, "Paul Bendall" <paul@...> wrote:
>
> Simon,
>=20
> Quite a few questions to answer.
>=20
> Firstly I would try to decide if you want a rackmount disk=20
> enclosure, like this 4 disk system from Scan.Com:
>=20
> http://www.span.com/catalog/product_info.php?
> cPath=3D18_2003_1703&products_id=3D13942
>=20
> Or, as the price is quite close to that of some of the NAS=20
solutions=20
> you could get these instead and use it as Network Attached Storage=20
> with is seperate to the system you are building:
> Synology - http://www.synology.com/enu/products/RS407/index.php
>=20
> Thecus - http://www.thecus.com/products_over.php?
> cid=3D12&pid=3D26&PHPSESSID=3D1a210621d77bdebf057eb58f73082165
>=20
> ReadyNAS - http://www.netgear.com/Products/Storage/ReadyNAS1100.aspx
>=20
> QNAP - http://www.qnap.com/pro_detail_feature.asp?p_id=3D71
>=20
> RAID is fairly simple and certainly at the four disk level:
> RAID 0 - No fault tolerance and disk read / writes are spread=20
across=20
> all four disks (therefore 4 times faster than a single disk).=20
> However, you are four times more likely to have a failure as a=20
> single disk failing will fail the entire array.
>=20
> RAID 1 - Is referred to as mirroing and needs two disks, each write=20
> is written to both disk at the same time therefore if one disk=20
fails=20
> te other takes over. In a four disk system you would have two=20
> separate mirrors (50% of your disk space is useable)
>=20
> RAID 5 - Most likely configuration in a four disk system. Disk=20
> writes are written across three disks and the fourth disk is used=20
to=20
> generate a parity (which means if any one disk fails the data is=20
not=20
> lost because it can be calculated from the parity disk). This is=20
> slightly simplistic as RAID 5 is distributed parity which means the=20
> parity could be on any one of the disks not on a single dedicated=20
> disk. Read performance is excellent as data is coming from three=20
> disks, write performance is better than a single disk but not as=20
> good as 3 disks because calculatting the parity degardes=20
performance=20
> slightly (however you have fault-tolerance and you are able so use=20
> 75% of total size of the disks)=20
>=20
> JBoD - Just a bunch of disks is not really RAID but you may find it=20
> mentioned. It means the disks are just individual disks and you=20
> would see them individually in the operating system.
>=20
> Also don't forget when talking about RAID the interface that the=20
> system uses. RAID used to be possible only with expensive SCSI=20
disks=20
> and controllers. However, with the advent of the SATA interface it=20
> is now much cheaper.
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> HTH
>=20
> Paul
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> --- In ukha_d@xxxxxxx, "simon.millward"
<simon.millward@>=20
> wrote:
> >
> > Hi guys, It's been a while since I last posted on this site, so
I=20
> > would like to say hello to everyone again.
> >=20
> > I have a question that I am hoping someone can help me with. I=20
> > recently looked into purchasing the basic Kaliedscape 3U
version,=20
> > until SWMBO saw the hefty =A314K price tag and asked me if I
could=20
> > build something cheaper. So that's my project now!!!
> >=20
> > So I must ask some questions of all the helpful souls out there.
> >=20
> > 1. I need a 19" Rackmount Sever Case that I can use as a
NAS. I=20
> have=20
> > looked around but can only find some that don't really suit. I=20
saw=20
> > one like http://www.raidware.com/chassis.htm
the 3U unit. I am=20
> > preferably after vertical mount hot swap drives.
> >=20
> > 2. I would like to be able to keep adding drives and it be
able=20
to=20
> > slot right in.
> >=20
> > 3. If I then decide to build another server, I would like it
to=20
be=20
> > able to cluster them.
> >=20
> > I must apologise for this post but when it comes to RAID I get
a=20
> > little confused. Also apologies if this sounds too much like
the=20
> > Kaliedascape version, but it is a brilliant idea just too=20
> expensive!!
> >
>



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