A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » General Hardware & Peripherals » General
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

RAID card for my PC??



 
 
Thread Tools Display Modes
  #1  
Old May 21st 04, 02:39 AM
TANKIE
external usenet poster
 
Posts: n/a
Default RAID card for my PC??

I have a ton of files (50 gig and growing) that I am very tired of backing up
and managing. I saw a RAID card for $60 for a PC that runs 2 mirrored hard
drives. Also saw 120 gig hard drives for $60.

Hmmm… for $180 I get true RAID with BIG drives in my desktop! This means
that I don't have to make periodic CD backups nearly so often. Change
something on one drive and it gets done on both without me having to think
about it. And it is very unlikely that both drives will go down at once.

What happens if one drive dies? Does the other one seamlessly take over, or
must the PC be rebooted? Do I have to take it apart to swap cables, or would it
just keep running? If it just keeps running, how do I know that a drive is
dead?

Are there any drawbacks to running RAID on a PC? Anyone have experience
mirroring drives like this? Your comments appreciated.

thanks

  #2  
Old May 21st 04, 03:42 AM
*Vanguard*
external usenet poster
 
Posts: n/a
Default

TANKIE said in :
I have a ton of files (50 gig and growing) that I am very tired of
backing up and managing. I saw a RAID card for $60 for a PC that
runs 2 mirrored hard drives. Also saw 120 gig hard drives for $60.

Hmmm. for $180 I get true RAID with BIG drives in my desktop! This
means
that I don't have to make periodic CD backups nearly so often. Change
something on one drive and it gets done on both without me having to
think about it. And it is very unlikely that both drives will go down
at once.

What happens if one drive dies? Does the other one seamlessly take
over, or must the PC be rebooted? Do I have to take it apart to swap
cables, or would it just keep running? If it just keeps running, how
do I know that a drive is dead?

Are there any drawbacks to running RAID on a PC? Anyone have
experience mirroring drives like this? Your comments appreciated.

thanks


You have confused mirroring with backup. Mirroring won't give you
backup for your files. The mirror drive gives you the same files as on
your primary drive. Also, writes will be slowed slightly (because it
must write the same data to 2 drives) but reads may be sped up if
round-robin read access is used. Mirroring is a *hardware* backup in
that it lets you recover from hardware disaster. While software RAID
may perform logical file reads to copy the files onto the mirror drive,
I have to wonder (but don't know) if hardware mirroring might not end up
giving you an exact mirror on a sector basis. That means if the
registry is screwed up on the primary than your "backup" on the mirror
drive is also corrupted. If your file system is corrupted then it is
also corrupted on the mirror drive. If hardware is used for mirroring
and if hardware mirroring makes an EXACT copy then it gets just as
screwed up as the primary drive. Mirroring is meant to let you quickly
get your system back to its prior state but only to that exact prior sta
te.

If you want backups, and to recover your system to an exact state as
before, get disk imaging software (DriveImage, Ghost, and I hear BingNT
makes disk images, too). You could get software that makes .iso disk
images but there is no compression. Ghost also has problems in that you
need to use the /IA switch to do a save of a physical disk image (that
reads sectors) rather than a logical one (that reads the files), but it
won't skip unused sectors and so it wastes space recording them.

While disk images are great for restoring your system to a known prior
(and probably good) state, disk images are a pain to use when you just
want to recover a few files, like your Word doc or a DLL file that goes
missing. DriveImage has its ImageExplorer to extract files from its
disk image fileset but it becomes very slow if you need to extract
thousands of files from a directory, like for all your clipart, and
appears to have problems extracting logical files from the physical
image for those that were EFS protected). So you'll still probably want
to use NT Backup or a 3rd party backup program to save logical copies
of, at least, your data files.

Use mirroring for physical recovery (i.e., hardware disaster recovery)
to get your computer back up quickly. Use disk images to provide you a
means of taking snapshots of your drive for recovery from logical
errors. If you want backups, use that 2nd drive as where you save disk
images and file backups. However, this 2nd drive will always be
spinning. Or, if removable, is still prone to mechanical failure. So
use it only for the most recent set of disk images and file backups from
where you copy them later onto removable media as you rotate through
them. Even if the backup hard drive fails, you'll still have the
removable media to use in another same-type drive or in a replacement
drive, so at most you lose one backup set if the hard drive fails. Of
course, if you only save one disk image and/or one file backup then it
needs to go onto removable media rather than a hard drive which is far
more prone to fail. Nothing like months down the road then finding out
your backup drive has "soft" sectors with reduced retentivity that
generate errors on reads made months or years after the writes. When
using removable media, ALWAYS enable the option to verify it contents.
Backup media that hasn't been verified that what it contains is what got
written to it often results in some very dire consequences later when
and only then you find you cannot read from that removable media, akin
to throwing spare batteries in your travel kit only to find while on
vacation in some remote location that the batteries were dead.

So decide whether you want to backup your files (as disk images or file
backups) or whether you want to backup the availability of your computer
(with mirroring). For a work desktop computer with critical development
performed on it or when used as a server, uptime is very important. For
a home computer, uptime is not critical and you just go get a
replacement drive on which you restore whatever snapshot (disk image) or
file backup you want. Hard drive die just through normal use but
removable media dies when it has been physically abused, so don't rely
entirely on a hard drive to let you restore a snapshot or files. I've
seen users that thought it was cool and easy to use a USB-connected hard
drive onto which they did a drive copy, saved one or more disk images,
or saved backup filesets only to later find the drive went dead or got
jarred enough so that it wasn't usable anymore and all their backups
were gone. Use the hard drive only as the first device in a rotation
set so you only have to explain or suffer the loss of just those backups
and still go back to removable media for the prior backup. Yes, the two
hard drives are not likely to fail at the same time - unless the damage
is common to both, like a PSU that goes beserk and outputs too-high
voltages (I got nailed by one but a long time ago), a power surge, ESD
at the controller or motherboard that runs up the common cable to both
drives, and so on. But then mirroring doesn't give you backup (of your
files). It just gives you quick recovery from hardware failure.

Although I save disk images, I also save file backups because often I
want to get at just one or few of my old data files. Note that the NT
Backup program will NOT compress your file backups. It only has the
option to *enable* compression if the [tape] device supports it. It
does do any compression on its own. You'll need a 3rd party backup
program that includes compression regardless onto what media it writes
its backup fileset. Also note that if you use the 2nd hard drive for
backups (instead of mirroring) using disk images that you will need to
configure your disk imaging software to slice up the disk image files
into sizes that will fit onto whatever removable media that you plan to
later move that snapshot fileset. For example, if you later intend to
save the disk image from the hard drive onto CD-R media then make sure
the disk image program creates files that are 650MB maximum in size.

--
__________________________________________________ __________
*** Post replies to newsgroup. Share with others.
*** Email: domain = ".com" and append "=NEWS=" to Subject.
__________________________________________________ __________


  #3  
Old May 21st 04, 03:51 AM
kony
external usenet poster
 
Posts: n/a
Default

On 21 May 2004 01:39:00 GMT, (TANKIE) wrote:

I have a ton of files (50 gig and growing) that I am very tired of backing up
and managing. I saw a RAID card for $60 for a PC that runs 2 mirrored hard
drives. Also saw 120 gig hard drives for $60.

Hmmm… for $180 I get true RAID with BIG drives in my desktop! This means
that I don't have to make periodic CD backups nearly so often. Change
something on one drive and it gets done on both without me having to think
about it. And it is very unlikely that both drives will go down at once.


A severe power surge or virus that takes down one would be quite likely to
take down the 2nd as well. Well, the virus just corrupts the files or
other logical mischief, but same difference so far as the data is
concerned.


What happens if one drive dies? Does the other one seamlessly take over, or
must the PC be rebooted? Do I have to take it apart to swap cables, or would it
just keep running? If it just keeps running, how do I know that a drive is
dead?


The manufacturer's utility will alert you when the drive has failed. Many
such utilities (maybe all of them by now?) will even email you. The
system will keep running and you would have access to all files still,
providing it really is just one of the two drives that failed, not some
other issue that would affect the whole PC.

RAID1 isn't as great a data backup strategy as it is a way to keep
important systems up and providing service 24/7 with no interruptions.



Are there any drawbacks to running RAID on a PC? Anyone have experience
mirroring drives like this? Your comments appreciated.

thanks


It is an additional level of safety but not a good replacement for backup
to a seperate system, drive or preferribly removable data, or for those
with really important data it's suggested to keep the backup off-site.

If for whatever reason you do feel a drive failure is likely you might
first determine WHY. The drawbacks are subtle, more noise, more heat and
electricity usage, over double the cost for drives and controller, and in
many cases the drive I/O is significantly slower from any configuration of
"PC" PCI IDE RAID than it would be from a southbridge-integrated IDE
controller. Read speeds are faster than if a single drive array but still
you might find a single drive attached to southbridge controller is
signficantly faster, though for many storage purposes it doesn't matter
how fast it is, should still be well above 30MB/s.

  #4  
Old May 22nd 04, 12:17 AM
DaveW
external usenet poster
 
Posts: n/a
Default

The RAID card that you are talking about does NOT offer data redundency.
You have to get a much more expensive card for that. If your RAID 0 setup
that you are considering has a harddrive fail, ALL data will be lost.

--
DaveW



"TANKIE" wrote in message
...
I have a ton of files (50 gig and growing) that I am very tired of backing

up
and managing. I saw a RAID card for $60 for a PC that runs 2 mirrored

hard
drives. Also saw 120 gig hard drives for $60.

Hmmm. for $180 I get true RAID with BIG drives in my desktop! This means
that I don't have to make periodic CD backups nearly so often. Change
something on one drive and it gets done on both without me having to think
about it. And it is very unlikely that both drives will go down at once.

What happens if one drive dies? Does the other one seamlessly take over,

or
must the PC be rebooted? Do I have to take it apart to swap cables, or

would it
just keep running? If it just keeps running, how do I know that a drive is
dead?

Are there any drawbacks to running RAID on a PC? Anyone have experience
mirroring drives like this? Your comments appreciated.

thanks



  #5  
Old May 22nd 04, 12:25 AM
Jean
external usenet poster
 
Posts: n/a
Default

"DaveW" schreef in bericht
news6wrc.36228$gr.3620517@attbi_s52...
The RAID card that you are talking about does NOT offer data redundency.
You have to get a much more expensive card for that. If your RAID 0 setup
that you are considering has a harddrive fail, ALL data will be lost.


+ people often forget the most important reason why taking backups: user
stupidity.
"Oops, I deleted that file. Now I still need it."

No RAID level can fix this ...

J.


  #6  
Old May 22nd 04, 01:09 AM
kony
external usenet poster
 
Posts: n/a
Default

On Fri, 21 May 2004 23:17:40 GMT, "DaveW" wrote:

The RAID card that you are talking about does NOT offer data redundency.
You have to get a much more expensive card for that. If your RAID 0 setup
that you are considering has a harddrive fail, ALL data will be lost.


Untrue, even the cheap SiI $15 cards do RAID1.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
difference in onboard SATA RAID versus card George General 3 March 1st 04 08:20 PM
What's a good SATA RAID card for Linux? Vadim General 0 February 11th 04 07:49 PM
Raid 10 - controller card recommendations? and where to buy? Alien Zord General 1 January 31st 04 12:55 AM
Incompatible RAID controller? @drian General 1 November 9th 03 08:38 PM
help. ga-7vrxp raid trouble, compatability and warning todd elliott General 0 July 17th 03 06:50 PM


All times are GMT +1. The time now is 12:16 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 HardwareBanter.
The comments are property of their posters.