What do I need to add RAID 1 SCSI to my computer?

[Ar Q]

My computer boots up from an IDE hard drive and writes all critical data to
a SCSI hard drive. It has an Adaptec 29160LP SCSI card.

I want to mirror the data drive using RAID 1. Besides buying another SCSI
hard drive, what do I need? Do I need another 29160LP SCSI card and an RAID
controller?

Thanks,

Ar Q

 

[Curious George]

My computer boots up from an IDE hard drive and writes all critical data to
a SCSI hard drive. It has an Adaptec 29160LP SCSI card.

I want to mirror the data drive using RAID 1. Besides buying another SCSI
hard drive, what do I need?

a second scsi drive a familiarity with the OS's raid capabilities (if
any) would do the job just fine.

 

[Ar Q]

a second scsi drive a familiarity with the OS's raid capabilities (if
any) would do the job just fine.

Don't want the software-based RAID.

 

[J. Clarke]

Don't want the software-based RAID.

Then you need to get a hardware-based RAID controller. LSI Logic, Intel,
and Adaptec are the major manufacturers for SCSI RAID controllers.
Personally I'd go with LSI or Intel over Adaptec unless there was some
compelling reason to do otherwise. However I'd also carefully consider
going with SATA RAID instead--LSI, Intel, Adaptec, 3Ware, and Tekram all
make SATA RAID solutions, some of which have substantially the same feature
set as their SCSI RAID controllers.

 

[Eric Gisin]

Don't want the software-based RAID.

Most SCSI hardware RAID performs poorly on the desktop, it is designed for RAID
5 on servers. Software RAID 1 performs well, but is not available in Win 2K/XP
Prof.

I would boot from the SCSI drive and get two IDE drives with a firmware RAID
controller for data.

If you want a backup solution, use an external drive instead, and manually back
up.

 

[Ar Q]

Then you need to get a hardware-based RAID controller.

Besides the RAID controller, do I need two SCSI cards?

 

[Curious George]

Besides the RAID controller, do I need two SCSI cards?

No. For hardware SCSI RAID 1 all you need is a raid controller, cable
with terminator and 2 scsi drives (should be matching size, preferably
identical drives). If you want to be fancy you can use 80pin sca
drives in a hot-swap backplane/cage. There are a lot of bad
backplanes and enclosures on the market tho. IMHO Supermicro products
are a decent value FWIW.

For only 1 RAD1 volume your choice of controller is pretty broad as
this doesn't require lots of cache or a fast processor and an older
U160 card will do just fine. In addition to the manufacturers already
mentioned that opens things up to Mylex (now owned by LSI) and in
addition some older IBM Serveraid controllers (which can often be used
on non-IBM servers). The IBM's are nice because they share a common
BIOS so an old controller is still supported through continual BIOS
and software updates. Compatibility with non-IBM machines is very
spotty though. The LSI Mylex are nice because the on-board software
is quite robust. Mylex are EOL though. Many people complain about
Adaptec performance but that should not really affect a simple volume
like this. Watch out for ZCR (zero channel raid) cards as they are
likely not what you need. They interface with a compatible on-board
scsi controller to upgrade it to raid functionality.

Make sure you review the manuals of whatever products you are
considering purchasing. With even simple RAID setups the devil is in
the details.

 

[Odie Ferrous]

My computer boots up from an IDE hard drive and writes all critical data to
a SCSI hard drive. It has an Adaptec 29160LP SCSI card.

I want to mirror the data drive using RAID 1. Besides buying another SCSI
hard drive, what do I need? Do I need another 29160LP SCSI card and an RAID
controller?

Thanks,

Ar Q

Your cheapest solution is going to be to buy another 29160 card and
another drive. On its own, the 29160 does not handle hardware RAID.
However, two of them will effectively give you disk duplexing (2
controllers, 2 drives) which used to be more hardy, in the heady days
when controllers occasionally failed.

The neatest solution would be to purchase a dedicated RAID card and an
additional drive.

Odie

 

[Folkert Rienstra]

Wotanidiot.

Your cheapest solution is going to be to buy another 29160 card and
another drive.

On its own, the 29160 does not handle hardware RAID.

Nor does it when doubled.

However, two of them will effectively give you disk duplexing

So what.

(2 controllers, 2 drives) which used to be more hardy, in the heady days when controllers occasionally failed.

The neatest solution would be to purchase a dedicated RAID card and an
additional drive.

Well, with zero channel Raid apparently only be usable with MoBo embed-
ded and approved SCSI it is the only solution.

 

[Curious George]

Nor does it when doubled.


So what.

no single point of failure of disk subsystem. See below.

Well, with zero channel Raid apparently only be usable with MoBo embed-
ded and approved SCSI it is the only solution.

I doubt he is using such a mobo as he is booting off PATA and using an
add-in card for scsi.

 

[Curious George]

Most SCSI hardware RAID performs poorly on the desktop, it is designed for RAID
5 on servers.

Umm if you say so..

The only problem I can think of for desktop is that some RAID BIOS
POSTs are so long. But some are fast also. Many handle RAID 5 poorly
performance wise and data verification wise.

Software RAID 1 performs well, but is not available in Win 2K/XP
Prof.

I would boot from the SCSI drive and get two IDE drives with a firmware RAID
controller for data.

Well that's doable but depending on the specifics that may or may not
represent an upgrade from a reliability standpoint.

If you want a backup solution, use an external drive instead, and manually back
up.

or external drives in addition to. Good raid 1 can help ensure
integrity of online data and that can come in handy even if you aren't
preoccupied with downtime from a drive suddenly and completely dying.
A backup scheme that is more than just a second copy sitting on the
same desk as the computer is always a good idea.

 

[Ar Q]

I would boot from the SCSI drive and get two IDE drives with a firmware RAID
controller for data.

If you want a backup solution, use an external drive instead, and manually back
up.

I want to build a computer with SCSI hard drives only. My follow up question
is that,
if I buy a two-channel SCSI RAID controller, could this be done? I like to
connect the boot hard drive on the first channel and two data drives (RAID
1) on different channels. (Basically, I have to put the boot hard drive and
one of the data drives in external SCSI closure. Therefore, it leaves the
other data hard drive inside the computer.)

Thanks,
Ar Q

 

[J. Clarke]

I want to build a computer with SCSI hard drives only. My follow up
question is that,
if I buy a two-channel SCSI RAID controller, could this be done?

Of course it could.

I like to
connect the boot hard drive on the first channel and two data drives (RAID
1) on different channels. (Basically, I have to put the boot hard drive
and one of the data drives in external SCSI closure. Therefore, it leaves
the other data hard drive inside the computer.)

You don't need two channels to do that.