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Billy T
02-08-2010, 05:16 PM
Hi Team

One of my RAID disks has fallen over (WD Caviar Black SATAII 640GB), the comp is still going on its twin, as indeed it should I guess, but I've updated my external backup just in case.

The only warning was a couple of hangs that cleared when I left it alone for 5 minutes.

I'll take it in for repair U/G tomorrow, but my question is, how safe is it to keep working tonight?

Cheers

Billy 8-{)

Nomad
02-08-2010, 05:28 PM
Hi Team

One of my RAID disks has fallen over (WD Caviar Black SATAII 640GB), the comp is still going on its twin, as indeed it should I guess, but I've updated my external backup just in case.

The only warning was a couple of hangs that cleared when I left it alone for 5 minutes.

I'll take it in for repair U/G tomorrow, but my question is, how safe is it to keep working tonight?

Cheers

Billy 8-{)

a friend's laptop hd might of crashed in Singapore ....
i took raid off my own one but i used a 2nd partition on the 1st hdd to sync files of my 2nd hdd and vice versa. i also have a external drive.

it was getting pricey to have 2 hdd as a raid, then perhaps 1 and 2 more for the 2nd drive, then have a external as well.

KarameaDave
02-08-2010, 05:33 PM
It is a risk to keep using it Billy, but no more than if you were just
running a single drive(which is what you will be doing).
You have a current external b/up, so safe enough I would think.

Nomad
02-08-2010, 05:33 PM
a related question if i may.

raid 1 has 2 hdd.

if i have a system drive and a drive containing my files. is it okay to shove all my stuff into one setup - raid 5 i think it's called. would my speed suffer as a result. or is it possible to have 2 individual raid 1? or 2 individual raid 5. hope you get my flow....


Cheers ..

KarameaDave
02-08-2010, 05:37 PM
Raid 5 is normally implemented with 3 drives (which is the minimum).
If it is 'Soft Raid' it will impact performance.
If hardware Raid, not so much.

http://en.wikipedia.org/wiki/RAID

Nomad
02-08-2010, 05:41 PM
if a person has a sys drive and a drive of personal files (pix for photoshopping etc).
is it okay to shove everything into that same raid 5? using 3 hdds as you say ...

is it possible at all to have like 2 sets of raid 1 or 5's?

or maybe use raid 5 with 4 drives if that provides a better balance ......

Billy T
02-08-2010, 06:03 PM
That sounds like my system, two disks in RAID-1 for OS & programs, two more for Data. Boy am I glad I did it this way.

The whole set up was $1900 ex gst and is conservatively specced because there will be no gaming etc: 2.66 GHz Intel CPU, ASUS P7PssD MB, 4 GB Kingston DDR3-1600 RAM, Corsair 650W psu, Sapphire ATI Radeon HD5750 512MB GDDR5 PCI-E video card, and Lian Li mid tower case. There are a few other custom bits and pieces and tweaks, nothing to write home about but suited to my particular needs.

Cheers

Billy 8-{)

Deimos
02-08-2010, 06:51 PM
I've been running a RAID 0 setup on every build for the last 10 years and have never had a hard disk fail.

I don't keep important files on my system so no biggie if one dies, and to date have only had RAID (with redundancy) pay off once, and have lost data because of my RAID 5 and RAID 0+1 array at least a couple of times.

These days I keep at least one backup of all my data and in some cases 2, unfortunately I learned that lesson the hard way...

BBCmicro
03-08-2010, 09:28 AM
I don't use RAID because of the temptation to use it for backup...

My (age-related?) problem is accidentally overwriting media source files. With a backup I can recover

Nomad
03-08-2010, 09:47 AM
the reason i quit raid now is that i don't need the speed and if i delete the file myself or hit by a virus it's kapuf. also it's more expensive.

i just do backups with 2 internals and 1 external.
i don't need time on all the time. if it crashes, i spend 30min to get it back on or a night - if i need to reorder a hdd.

Agent_24
03-08-2010, 12:33 PM
This is why the RAID edition drives from WD have TLER to prevent the array from breaking in the event of an error like this.

Billy T
05-08-2010, 02:01 PM
Well, I'm back on line, one new U/G disk later. Bought a spare as well so that next time (there is always a next time with computers!) I can just pop in the new disk and away we go. Turns out that under RAID-1 the usual means of tracing which disk has died is simply to swap in the new disk, position by position, until the fault indication clears.

In this instance I had a fair idea that it was one of the OS disks because there were a few hangs before it quit (after which it stopped hanging and behaved itself) so it seems to be a straightforward fix.

Apparently Windows can't tell you which disk is AWOL, something to do with SATA protocols I believe. Anyway, this is how they fixed it, so who am I to argue?

Cheers

Billy 8-{)

Billy T
05-08-2010, 03:17 PM
I've been running a RAID 0 setup on every build for the last 10 years and have never had a hard disk fail.

I don't keep important files on my system so no biggie if one dies, and to date have only had RAID (with redundancy) pay off once, and have lost data because of my RAID 5 and RAID 0+1 array at least a couple of times.

As I read it, when researching RAID for this computer, RAID 0 is striped so unless you use a parity bit, if one disk fails you lose the lot, so this configuration is principally an access-speed enhancer. Just as well you haven't had a disk failure then.

RAID 1 is simply mirroring on two disks, while RAID 0+1 has both striping and mirroring to give the best of both worlds, but requires 4 disks to implement, so that was out of the question for me as it would have required 8 disks to keep OS/Progs and Data separate, and the RAID 2 to RAID 6 options were outright overkill.

I can't see how you could lose data on RAID 0+1 unless you had a multiple disk fry-up, and likewise with RAID 5, which is another 4 disk configuration, a single disk failure will not lose data but you have to rebuild promptly as a second failure will see you kumara'd.

No doubt an expert will correct me if I'm wrong. :D

Cheers

Billy 8-{)

CYaBro
05-08-2010, 03:21 PM
Any RAID setup is not a true backup because if the machine with the RAID setup in it gets stolen, blown up, flooded etc etc then RAID won't save your data.
You need to backup to an external source and preferably take that off site as well.

Agent_24
05-08-2010, 03:38 PM
The main point of RAID is to increase reliability and\or increase performance.

It is not a replacement for an off-site backup by any means.

kahawai chaser
05-08-2010, 03:46 PM
Glad I have not bothered about raid, I mean is it necessary for usual home based purposes? Might add unneeded complexity, or desire to enhance/experiment even more without any noticeable user advantage. Won't operating systems, vigilance, security measures be enough for performance and reliability. Unless if you are running different operating systems - e.g. home/family, and business or similar.

Deimos
05-08-2010, 05:18 PM
As I read it, when researching RAID for this computer, RAID 0 is striped so unless you use a parity bit, if one disk fails you lose the lot, so this configuration is principally an access-speed enhancer. Just as well you haven't had a disk failure then.

RAID 1 is simply mirroring on two disks, while RAID 0+1 has both striping and mirroring to give the best of both worlds, but requires 4 disks to implement, so that was out of the question for me as it would have required 8 disks to keep OS/Progs and Data separate, and the RAID 2 to RAID 6 options were outright overkill.

I can't see how you could lose data on RAID 0+1 unless you had a multiple disk fry-up, and likewise with RAID 5, which is another 4 disk configuration, a single disk failure will not lose data but you have to rebuild promptly as a second failure will see you kumara'd.

No doubt an expert will correct me if I'm wrong. :D

Cheers

Billy 8-{)

I had power drop out on 2 of my 4 disks in Raid 0+1, the disks were still fine after I fixed the power but the data was toast.

I also had a replacement disk fail while rebuilding data on an already failed array, data was toast, so yeah, lesson learned, now I've got about 6-7 1TB disks floating around with a copy of all my data.

Agent_24
05-08-2010, 07:21 PM
Glad I have not bothered about raid, I mean is it necessary for usual home based purposes? Might add unneeded complexity, or desire to enhance/experiment even more without any noticeable user advantage. Won't operating systems, vigilance, security measures be enough for performance and reliability. Unless if you are running different operating systems - e.g. home/family, and business or similar.

For a normal home user I would say it does not offer much of an advantage compared to the extra cost and work to set it up.

If you were regularly authoring movies or something and wanted to make sure your PC didn't crash in the event of a drive failure then a mirrored RAID for your OS drive would be useful, but you'd probably be more likely to kick your power cord out.

Billy T
05-08-2010, 07:53 PM
The main point of RAID is to increase reliability and\or increase performance. It is not a replacement for an off-site backup by any means.

For me it is an ongoing concurrent backup during daily work, and if a disk fails between normal backups (which I do to an external drive that can be taken off site) not only do I not lose data, but provided I back up every few minutes to the external drive, I can just keep on working with minimal risk.

I don't think many PF1 members would have 'off-site backup' facilities, and in fact I doubt that many small to medium sized businesses would either.

There is no other system that can keep on recording data input beyond the point of failure of a hard drive and as a one person business, I do not have the luxury of IT support.

However, it was my OS/Program drive that failed and that would normally have seen me starting the laborious process of intalling and configuring all my programs again (if I hadn't imaged it). Instead I am back to normal and everything is as it was, all for the mighty initial cost of around $440 for four 640GB disks.

For me, that's a no-brainer!

Cheers

Billy 8-{)

BBCmicro
05-08-2010, 08:30 PM
For me [raid] is an ongoing concurrent backup

Personally I don't think the word 'backup' should be used in connection with RAID. As Nomad said above, RAID is not a backup if you delete an important file or get an intractable infection.

To spell it out, the deleted file will disappear from both drives and the malware will kill both drives too.

Much better to use the second drive as an ordinary backup. You hit a hotkey every now and then and save a copy of your current project onto the backup drive.

If you are worried about hardware failure, a system image on another disc is the way to go

somebody
05-08-2010, 08:41 PM
As I read it, when researching RAID for this computer, RAID 0 is striped so unless you use a parity bit, if one disk fails you lose the lot, so this configuration is principally an access-speed enhancer. Just as well you haven't had a disk failure then.

RAID 1 is simply mirroring on two disks, while RAID 0+1 has both striping and mirroring to give the best of both worlds, but requires 4 disks to implement, so that was out of the question for me as it would have required 8 disks to keep OS/Progs and Data separate, and the RAID 2 to RAID 6 options were outright overkill.

I can't see how you could lose data on RAID 0+1 unless you had a multiple disk fry-up, and likewise with RAID 5, which is another 4 disk configuration, a single disk failure will not lose data but you have to rebuild promptly as a second failure will see you kumara'd.

No doubt an expert will correct me if I'm wrong. :D

Cheers

Billy 8-{)

I've got 4 disks, with RAID0 striped across 4 disks for OS + software, and RAID1+0 for data. My position is that I'm willing to take the risk that losing one disk will cause me to lose my OS, but then again, I have frequent full-image backups (locally and offsite) so I could restore that quickly if I needed to.

plod
05-08-2010, 10:03 PM
For me it is an ongoing concurrent backup during daily work, and if a disk fails between normal backups (which I do to an external drive that can be taken off site) not only do I not lose data, but provided I back up every few minutes to the external drive, I can just keep on working with minimal risk.

I don't think many PF1 members would have 'off-site backup' facilities, and in fact I doubt that many small to medium sized businesses would either.

There is no other system that can keep on recording data input beyond the point of failure of a hard drive and as a one person business, I do not have the luxury of IT support.

However, it was my OS/Program drive that failed and that would normally have seen me starting the laborious process of intalling and configuring all my programs again (if I hadn't imaged it). Instead I am back to normal and everything is as it was, all for the mighty initial cost of around $440 for four 640GB disks.

For me, that's a no-brainer!

Cheers

Billy 8-{)
I think its time you seriously look at something like carbonite for proper off site back up
http://www.carbonite.com.au/?gclid=CKat5tGJoqMCFRhaiAod_HOi4g

Billy T
06-08-2010, 10:54 AM
Personally I don't think the word 'backup' should be used in connection with RAID. As Nomad said above, RAID is not a backup if you delete an important file or get an intractable infection.

So when the first disk failed, the data stored on the second disk wasn't a back-up? Gimme a break! That's a semantic argument at best, but plain old-fashioned pettifogging in my view.

I think you are missing the point. There are limits to how far a small business can go in IT expenditure. Raid protects against a single disk failure (or in this case two disks, data and OS), but if I not taken advantage of that facility, had it been the data disk I could have lost all work and emails since my last back up, and that was already stored on an external drive.

Realistically I don't think anybody runs an 'instant backup' system so that no data is lost at all, therefore RAID-1 is excellent low-cost insurance between backups. Sure a major lightning strike or other electrical catastrophe could kill both sets of drives simultaneously, but what's the chances of that? Even if it did happen, I only lose work since the last backup, and on critical reports I actually print drafts at each key stage because I find them easier to proof and edit on paper (call me old-fashioned) so I can easily re-enter the work rather than recreating it. Off-site storage is no safer either, data centres have blown up or burned down, financial issues have closed some without warning, and I don't think I'll ever entrust my future to cloud storage, at least not until I have wings and a harp.

Cheers

Billy 8-{)

SolMiester
06-08-2010, 11:01 AM
Actually, I run shadow copies on my file server, which is a form of Backup..runs at 10, 12 and 2 each day...
Saves me getting the backup tapes out and usually have a file back in about 5 seconds..haha!

Agent_24
06-08-2010, 12:31 PM
The point of a backup is meant to provide protection against as many data loss scenarios as possible.

In a mirrored RAID array the level of backup protection it provides is low, all you protect against is single (or multiple) drive failure depending on your amount of drives that are mirrored.

In the event of a fire, theft, catastrophic PSU failure, lightning stike, flood, etc you lose both drives, and your 'backup' is useless.

Even an external hard drive in another room provides protection against a lot more things than just RAID.

Of course your methods as you describe above are very sensible, and RAID mirroring plays an important role, but it is more a role of high availability than a backup.