Is RAID worth it?

  • Thread starter Thread starter Ron O'Brien
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R

Ron O'Brien

I was just about to install a larger C: drive on my PC which was configured
as RAID0 (there are also two other HDD's for data/storage set as RAID1),
then I read a thread from within this newsgroup in which Carey Frisch
(Microsoft MVP) directed someone to read - Why RAID is (usually) a Terrible
Idea http://www.pugetsystems.com/articles?&id=29 and that has made me
re-think my plans.

Is RAID really worth? it is a much more complex setup and a nightmare when
things go wrong and, as the article points out, there is a 25 - 30% chance
something will go wrong. Indeed my own experience of a previous PC with
RAID1 showed that it was by no means an easy task to restore everything when
one HDD did fail after just 4 months.

So I'm left with a total of 4 HDD's and wondering if I should even consider
RAID, OK so I do a bit of HD video editing and RAID0 'could' speed things
up, but will I really notice that gain? I have equally undertaken HD video
editing on a much less powerful non-RAID PC and managed OK.

The one think that RAID1 'was' in my mind (and I would suggest in the mind
of many others) always useful for was data protection (but with loads of
hassle) so I'm thinking there must be a way whereby I can install all four
drives so that only two are visible and the other two are a mirror image set
so that at the end of the day, or maybe twice a day, some software would
back up the main visible drives to the 'invisible' back-up drives. Thus if
any drive failed, I could just switch connectors and re-boot.

Now, is what I've said a pipe dream or can it happen, and if so what
software and are there any obvious pitfalls - apart from the time to make
the back-up at the end of each day?
 
Ron,
Its an interesting question.
The point of RAID is for an easier and quicker recovery from disk failure.
With a proper hardware RAID card, I don't see you would have a problem. When
a drive fails you just swap it out.
An alternative and simpler solution is to use a Recovery partition on a
different drive. Altiris or Acronis do this. It is a really simple way of
getting some reassurance that you can recover quickly. The difference
between this and RAID is that you have a snapshot rather than real time
copy, so you will lose something; but conversely you can have multiple
differential snapshots. RAID will not help you roll back if you have a
software fault, whereas a Recovery solution will.
Hope that helps,
Anthony,
http://www.airdesk.com
 
Anthony

Thanks for your response, which does help.

I am also wondering about the speed aspect of RAID. I understand that RAID0
gives the fastest speeds, but offers no recovery benefits, whereas RAID1
offers the facility to just replace a drive (in theory at least - it wasn't
quite as straight forward when this happened to me some time ago!) but
whilst RAID1 speed is better than a non-RAID system it does not offer the
speed advantages of RAID0.

Which then leads to the next obvious question, would you 'actually' notice
the speed benefits or would you just be kidding yourself that this new RAID1
set up is brilliantly fast simply because it is newly setup and has no
clutter, no fragmented files, no left-over uninstall debrie etc etc that you
'old' PC had.

Also, we all know that you can buy two identical components one of which
could be far faster and more efficient than the other, so again, you have to
ask how efficient the rest of your setup is, including the hard drives (and
even the leads) when added to the RAID1 setup, again if any such component
has marginally passed the manufacturers quality control tests, would their
impact further reduce the RAID1 speed benefits - to possibly less than a
good non-RAID system

Ron
 
Ron O'Brien said:
I was just about to install a larger C: drive on my PC which was configured
as RAID0 (there are also two other HDD's for data/storage set as RAID1),
then I read a thread from within this newsgroup in which Carey Frisch
(Microsoft MVP) directed someone to read - Why RAID is (usually) a Terrible
Idea http://www.pugetsystems.com/articles?&id=29 and that has made me
re-think my plans.

Is RAID really worth? it is a much more complex setup and a nightmare when
things go wrong and, as the article points out, there is a 25 - 30% chance
something will go wrong. Indeed my own experience of a previous PC with
RAID1 showed that it was by no means an easy task to restore everything
when one HDD did fail after just 4 months.

So I'm left with a total of 4 HDD's and wondering if I should even
consider RAID, OK so I do a bit of HD video editing and RAID0 'could'
speed things up, but will I really notice that gain? I have equally
undertaken HD video editing on a much less powerful non-RAID PC and
managed OK.

The one think that RAID1 'was' in my mind (and I would suggest in the mind
of many others) always useful for was data protection (but with loads of
hassle) so I'm thinking there must be a way whereby I can install all four
drives so that only two are visible and the other two are a mirror image
set so that at the end of the day, or maybe twice a day, some software
would back up the main visible drives to the 'invisible' back-up drives.
Thus if any drive failed, I could just switch connectors and re-boot.

Now, is what I've said a pipe dream or can it happen, and if so what
software and are there any obvious pitfalls - apart from the time to make
the back-up at the end of each day?
Click to expand...


You would be better off by placing two of the drives into external housings
and using them for OS images and important data.

RAID is worth the trouble for mission critical stuff where there is an
accomplished system administrator on hand to fix problems..

For the average user in an office pool or at home, RAID = bragging rights..


--
Mike Hall - MVP
How to construct a good post..
http://dts-l.com/goodpost.htm
How to use the Microsoft Product Support Newsgroups..
http://support.microsoft.com/default.aspx?pr=newswhelp&style=toc
Mike's Window - My Blog..
http://msmvps.com/blogs/mikehall/default.aspx
 
Ron,
If you want speed, then you need to be looking for SCSI or SAS drives, 15k
RPM. A high end workstation will be built like this. Its only part of the
overall performance, but for example if you are editing images or movie
files you will certainly notice it.
An array controller will speed things up marginally for a given speed of
disk, because you have a read/write cache. I don't know of anyone who
implements RAID in order to achieve speed, though. Its for fault tolerance.
Anthony,
http://www.airdesk.com
 
My 2.5 year old Gateway FX-510X came with XP MCE and a RAID 0 array ( 2x250
GB) since it was designed as a media machine.
I'm still running RAID 0 under Vista and it works great.
 
RAID0 is very dangerous. It effectively doubles your change of complete
catastrophic data loss. The only time it might be appropriate is on a
gaming only machine which has been fully backed up and is not used at all
for data.

RAID1 has its merits. We use it routinely on servers (especially in small
business where RAID5 or other more costly options are not popular). It's
value is not purely data redundancy, but the fact that a server can continue
running when one drive fails. It is not a substitute for daily backup but a
useful adjunct. I find its use in home situations less clear. Some of the
raid controllers (e.g. built into motherboards) are not of the best quality
and, as you note, it adds some complexity. On balance I would say that
frequent backups are usually sufficient for a home use PC and that RAID1 is
useful for servers.
 
You can buy a motherboard that includes multiple raid controlers for about
£70, or less.
But there again you can opt for a high end Raid card in the order of £300
The two are completely different, both in performance, reliability and
support.
However raid, of any type, is not a replacement for backups.
The particular model of HD can also make a difference, they are not all
equal.
 
Many companies build their servers with 6 drives in a 5 drive RAID 5
configuration. This protects the data in the basic 5 drive array from the
failure of any single drive. And in case any of the 5 drives fail the 6th
drive is automatically configured to replace the failed drive so the system
is still protected. The failed drive is then replaced.
Of course backups stored in another computer center or in an off site
location are also required in case the center in which the servers are
located is destroyed.
DL said:
You can buy a motherboard that includes multiple raid controlers for about
£70, or less.
But there again you can opt for a high end Raid card in the order of £300
The two are completely different, both in performance, reliability and
support.
However raid, of any type, is not a replacement for backups.
The particular model of HD can also make a difference, they are not all
equal.
Click to expand...
 
I used RAID0 for 4 years and had no problems - 2x200GB Cudas on a Intel
ICH5R (P4C800ED mobo); I had a defective SATA cable but I did not lose any
data. RAID0 is worth due to gain in speed/productivity.
Just 2 points - mostly home users:
1. use good quality hardware.
2. organize your files such that you can easily backup your documents and
whatever you create/modify daily.

Again, for a home user, I do not see the need to backup in real time the OS
and whatever software; you can reinstall those easily from backup images.
Michael
 
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