The Bad Raid 0 - My Experience

[Beggar]

I setup a RAID 0 system and want to share my experience here. There is so much bad talking about RAID 0 on the internet.

My OS is WinXP SP3. I have the GAS-P55-UD6 with 3 RAID controllers - I took the Intel Matrix for my RAID setup - Intel® ICH8R/ICH9R/ICH10R/DO/PCH SATA RAID Controller with driver version 8.9.0.1023.

The CPU is the I7-860 and the two HDs for my RAID 0 setup are two Seagate 1 TB (ST31000528AS) - so in total 2 TB. The are divided into two RAID areas of about 2 x 931 GB to reduce the access time and to reduce bad effects of defragmentation. Strip Size I took 64 KB what seems to be the best for MY system.

I moved my existing non RAID system to the two RAID disks without any problems. But I made sure that the OS on the old non RAID disk had the RAID drivers installed already - this is important - but easy to do.

Then I made many tests with the RAID setup. Even often switching off the power during massive disk write operations. Problems none at all. My WinXP had to scan the disk for errors but it is the same with a non RAID setup.

What did RAID bring? The performance depends what you are doing. Virus scans are more than 2 times faster. Start from Hibernation takes a fraction of the time of the non RAID setup on a 4 GB memory system. Before I could drink a coffee. System boot not so much difference because most of the time is spend with loading and activating drivers. All disk intensive applications will benefit a lot. Applications will start faster - the bigger the application the higher the benefit you feel.

All in all I would NEVER use a system without RAID 0 again. The old argument disk failure? You have this problem with a non RAID setup too. And I always have a backup on external disks - bootable with the current OS. Almost a complete mirror. So what?

But it goes even faster. Smaller applications with a lot of disk access I put on a RAM disk - Firefox for instance. Nothing is faster ;-) But sure - don't expect no data loss if you switch off the power. My RAM disks are saved only at system shutdown. So this would reset me to the data of the last shutdown.

Problems I found but knew before:

S.M.A.R.T. data will not be available anymore. This means not even the temperature of the HD. Intel provides a warning if the SMART data show a problem. But based on what data I could not find anywhere. But SMART data are mostly good for nothing and the temperature? It is interesting for a while but that is it.

Some partition tools will get a problem when started from CD after reboot - they will not find disks. Acronis was one of them at least at my system. But Paragon Partition Manager does a perfect job. You have to check other boot tools too.

Acronis True Image Home works without any problems and can restore a non RAID backup to the RAID disks (but again - you should have installed the RAID drivers on this backup). No problems with boot usage.

Defragmentation tools become more or less useless. You can only do a logical defragmentation for Windows but not directly move the data on the disks. They are controlled by the RAID driver and nothing else.

This is what I found so far. If anybody knows more problems please let me know. But please not the disk failure argument. Disk failure is always possible with whatever setup. In all the many years I have been using computers (35 and this almost daily) I never had a data loss because of disk failure. And I always had backups even if I never needed them to repair a disk failure - but often to fix my mistakes.

[stolidfeline]

Thank you for posting this very useful information.

I hope it encourages others to speed up their disk access times, Many have been afraid to try it due to the "scaremongers".

I have also been using hard disks since the PC/AT days. Ever since my original ST225 which cost a fortune for 10Mb (I think it was).

I've never lost data due to normal HDD failure. The only exception to this has been in Thailand, due to power surges, I recall especially one incident when a power transformer on a pole in the street outside exploded. That one took out a power supply, motherboard, hard disk, and CPU. Having a UPS did not help in this instance. Oh, and of course, I have also suffered the usual problem with Maxtor hard disks, about 7 of which failed a few years back.

The current range of Western Digital "green" drives are very good. Unfortunately since the data density on the platters is almost doubled, so as to make future large capacities obtainable in the near future, this would mean a disk running at the same 7200 rpm would have to read data almost twice as quickly. Since this is not at the moment feasible, WD reduced the speed to 5400 rpm - which made many people think they would be slower. Nevertheless it is still as fast if not faster than previous drives. Head parking every few seconds is very easily disabled with wdidle3.exe

I use many of these 1TB drives in RAID0 setups and can recommend them.

[losworld]

has the forum really come to this?

[dave_boo]

I setup a RAID 0 system and want to share my experience here. There is so much bad talking about RAID 0 on the internet.

You realise why there's so much 'bad talking' about RAID-0, right?

My OS is WinXP SP3. I have the GAS-P55-UD6 with 3 RAID controllers - I took the Intel Matrix for my RAID setup - Intel® ICH8R/ICH9R/ICH10R/DO/PCH SATA RAID Controller with driver version 8.9.0.1023.

The CPU is the I7-860 and the two HDs for my RAID 0 setup are two Seagate 1 TB (ST31000528AS) - so in total 2 TB. The are divided into two RAID areas of about 2 x 931 GB to reduce the access time and to reduce bad effects of defragmentation. Strip Size I took 64 KB what seems to be the best for MY system.

You realise that if you have to access both partitions sequentially you've essentially doubled the access time?  Furthermore, as stated later in your post, your reason to 'reduce bad effects of defragmentation' is by definition a non-reason?

I moved my existing non RAID system to the two RAID disks without any problems. But I made sure that the OS on the old non RAID disk had the RAID drivers installed already - this is important - but easy to do.

When you formated the volume, did you match the stripe value?

Then I made many tests with the RAID setup. Even often switching off the power during massive disk write operations. Problems none at all. My WinXP had to scan the disk for errors but it is the same with a non RAID setup.

To be expected....

What did RAID bring? The performance depends what you are doing. Virus scans are more than 2 times faster. Start from Hibernation takes a fraction of the time of the non RAID setup on a 4 GB memory system. Before I could drink a coffee. System boot not so much difference because most of the time is spend with loading and activating drivers. All disk intensive applications will benefit a lot. Applications will start faster - the bigger the application the higher the benefit you feel.

And what about applications that are large and have a lot of small files to load?  What's the performance on that?

All in all I would NEVER use a system without RAID 0 again. The old argument disk failure? You have this problem with a non RAID setup too. And I always have a backup on external disks - bootable with the current OS. Almost a complete mirror. So what?

Sigh...

Per this link you've cut the MTBF down to 350 000 hours for your array.  But putting that aside, let's say that you lose a drive.  Ok, you have back ups, nearly a complete mirror.  You buy a new drive, which isn't a problem because they're cheap as chips.  But when you're rebuilding the array, how do you know that the stress won't push the other one over the edge?

But it goes even faster. Smaller applications with a lot of disk access I put on a RAM disk - Firefox for instance. Nothing is faster ;-) But sure - don't expect no data loss if you switch off the power. My RAM disks are saved only at system shutdown. So this would reset me to the data of the last shutdown.

You only have 4 GB on your quad core machine (running WinXP) and you lopped off some RAM for a ramdisk?  I'm assuming, since you didn't mention it, that you only see some 3,2GB of RAM because it doesn't appear that you're on WinXP 64....interesting choice.

Problems I found but knew before:

S.M.A.R.T. data will not be available anymore. This means not even the temperature of the HD. Intel provides a warning if the SMART data show a problem. But based on what data I could not find anywhere. But SMART data are mostly good for nothing and the temperature? It is interesting for a while but that is it.

Yeah, all those nifty reliability tests are just there for some engineer to look busy.

Some partition tools will get a problem when started from CD after reboot - they will not find disks. Acronis was one of them at least at my system. But Paragon Partition Manager does a perfect job. You have to check other boot tools too.

Acronis True Image Home works without any problems and can restore a non RAID backup to the RAID disks (but again - you should have installed the RAID drivers on this backup). No problems with boot usage.

Or you could run a real controller.....

Defragmentation tools become more or less useless. You can only do a logical defragmentation for Windows but not directly move the data on the disks. They are controlled by the RAID driver and nothing else.

This is what I found so far. If anybody knows more problems please let me know. But please not the disk failure argument. Disk failure is always possible with whatever setup. In all the many years I have been using computers (35 and this almost daily) I never had a data loss because of disk failure. And I always had backups even if I never needed them to repair a disk failure - but often to fix my mistakes.

And that's the real problem isn't it?  Some n00b will see your post and think that they can get away with running RAID-0.  But there's more to it than that isn't there?

Thank you for posting this very useful information.

I hope it encourages others to speed up their disk access times, Many have been afraid to try it due to the "scaremongers".

I have also been using hard disks since the PC/AT days. Ever since my original ST225 which cost a fortune for 10Mb (I think it was).

I've never lost data due to normal HDD failure. The only exception to this has been in Thailand, due to power surges, I recall especially one incident when a power transformer on a pole in the street outside exploded. That one took out a power supply, motherboard, hard disk, and CPU. Having a UPS did not help in this instance. Oh, and of course, I have also suffered the usual problem with Maxtor hard disks, about 7 of which failed a few years back.

The current range of Western Digital "green" drives are very good. Unfortunately since the data density on the platters is almost doubled, so as to make future large capacities obtainable in the near future, this would mean a disk running at the same 7200 rpm would have to read data almost twice as quickly. Since this is not at the moment feasible, WD reduced the speed to 5400 rpm - which made many people think they would be slower. Nevertheless it is still as fast if not faster than previous drives. Head parking every few seconds is very easily disabled with wdidle3.exe

Wow, that's gotta be the biggest load of tripe I've seen in this forum since Reimar left.  They're green because they're lower power...not because SATA couldn't transmit the data fast enough.

I use many of these 1TB drives in RAID0 setups and can recommend them.

has the forum really come to this?

Sadly it appears so.

[Crushdepth]

All in all I would NEVER use a system without RAID 0 again. The old argument disk failure? You have this problem with a non RAID setup too. And I always have a backup on external disks - bootable with the current OS. Almost a complete mirror. So what?

So you have more than double the risk of destroying the whole RAID and the potential to lose twice as much data. But if you keep current backups and *test that they work* regularly hey, go for your life.

I use many of these 1TB drives in RAID0 setups and can recommend them.

You are better off using lower capacity drives if you can - do you *need* several TB of storage? If not, why pay for it? The higher the storage capacity of a hard drive the more densely packed the data and the more inherently unreliable it is. Save your money and improve the reliability of your system at the same time.

[Beggar]

has the forum really come to this?

Sadly it appears so.

I enjoy that I found a person with so much knowledge about RAID like you. But you understand that it is not enough to say it is bad. So please let me know what exactly you did and what exactly went wrong. What OS system, what RAID controller, what RAID setup (disks, areas, strip size, partitions, cluster), etc. And please write in detail what went wrong so that everybody can avoid to make the same mistake.

[thunder30101]

Well davewhoever since you dissed reimar, who i dont know or care about, I feel you are fair game to reply on this subject. you are not the know all on raid that you think you are, you seem to come on here and talk alot of crap on how much you know about raid systems but you are living in the past as many outdated fools are.software raids are every bit as capable as hardware raids are and have been for many years now, so why dont you get your head out of your arse and start showing us all some stats on your claims instead of just disrespecting people ???? Put up or shut up my friend and lets see your stats and data to back it up.

[surface]

All in all I would NEVER use a system without RAID 0 again. The old argument disk failure? You have this problem with a non RAID setup too. And I always have a backup on external disks - bootable with the current OS. Almost a complete mirror. So what?

I think you'll find that you've jumped into RAID 0 with spindles at a time when SSD's have removed any need for these on desktops. While RAID 0 with spindles may still be useful for video editing, there's no reason to go that route anymore for everthing else. Who need's 1GB+ on their system partition? It's obviously cheaper to get 2x500GB drivers than 1x80GB SSD and 1X500GB spindle, but people spending money on RAID arrays for their home computer aren't usually concerned about a couple hundred dollars in the first place.

Glad to hear you've actually noticed a difference! In the past I've never experienced a real difference with desktop usage on RAID 0 setups, and that was with 15k SCSI and expensive controllers.

[monkfish]

One X Raid user here.

The HD won't fail but the controller probably will.

In which case I recommend R-Studio to recover any lost dats.

[JSixpack]

Wow, that's gotta be the biggest load of tripe I've seen in this forum since Reimar left.

Quite a big load, heh.

Much nicer place now, ain't it?

[Beggar]

I think you'll find that you've jumped into RAID 0 with spindles at a time when SSD's have removed any need for these on desktops. While RAID 0 with spindles may still be useful for video editing, there's no reason to go that route anymore for everthing else. Who need's 1GB+ on their system partition? It's obviously cheaper to get 2x500GB drivers than 1x80GB SSD and 1X500GB spindle, but people spending money on RAID arrays for their home computer aren't usually concerned about a couple hundred dollars in the first place.

Why do I need 2 TB in my desktop and why do I not use SSDs? Let me explain you my situation.

All in all I have about 9 HDs running with a total of about 7.5 TB. 3 disks with a total of 3 TB are in the desktop. The rest are external connected with eSATA or USB and active when needed.

2 TB inside the desktop are for the RAID. The single TB is for quick backups or target for video rendering or risky tests like migrating my setup from XP to Vista and then to Win 7. Or for instance to re-test Software like Norton Partition Magic with a new system. It could not handle the 3 different SATA controllers of my new motherboard and just destroyed partitions. Paragon did a better job. But better to check this with a disk for scrap.

In addition to this I have endless burned DVDs and DVD-RW. Why so many? In more than 35 years computer usage I collected many data in computer format. All my old photos and color slides are scanned in a computer format (tif format), as well as all my videos I took from traveling (DV and finally DVD-format), all my music CDs are on HDs (flac format), etc. Most of these formats take a lot of space. 1 scanned photo in tif about 20-30 MB, 1 pop song in flac format about the same, 1 hour DV format about 13 GB. All those data do not exist in the original format anymore - they were not convenient enough to handle.

Then I want to get rid of all my DVDs. It takes so much time to burn them and check the burn quality. I am too lazy to use them afterwards - have to search and put them in the DVD drive and... For me DVDs are a thing of the past. Blue-Ray will not change this.

SSDs are the future - no question. But for my storage and performance needs they still have a long way to go. The price? 1 TB Seagate Baht 2940. Some people spend more in a bar in 1 night. After all the years here I do not go to bars so often anymore ;-)

[dave_boo]

I enjoy that I found a person with so much knowledge about RAID like you. But you understand that it is not enough to say it is bad. So please let me know what exactly you did and what exactly went wrong. What OS system, what RAID controller, what RAID setup (disks, areas, strip size, partitions, cluster), etc. And please write in detail what went wrong so that everybody can avoid to make the same mistake.

Hmm...which array?  I've used PATA, SCSI, and SATA.  All controllers were from 3ware, except for the SCSI which has been exclusively LSI.  Have used WinXP, but otherwise SuSE.  The XP was setup on a 5 drive Seagate PATA.  Never had problems.  Actually had one drive drop out, but running RAID 5 with a hot spare I just got home and replaced the bum drive.  It was, obviously, NTFS with a cluster/stripe size of 64.  480(ish) GB safe.  The controller was moved to my Linux machine and drives upgraded, 5x250 GB with one hotspare.  Never had a drop out.  ReiserFS with single partition.  The SCSI drives are 4x 73GB 15k running EXT2.  In RAID 0 with stripe/cluster at 64.  Don't have anything of import on them, and they've been running steady for 4+ years now.  However, if they do go down I have an LTO back up that will be dumped on them and will be back up and running.  Has / on it.  Have my SATA array running 5x 73gb Raptors.  ReiserFS and RAID 5.  It's a play around partition mostly.  New distros are demoed and proven, but /home is also on there.  I went with, bucking the trend, 128k on that pool.

Well davewhoever since you dissed reimar, who i dont know or care about, I feel you are fair game to reply on this subject. you are not the know all on raid that you think you are, you seem to come on here and talk alot of crap on how much you know about raid systems but you are living in the past as many outdated fools are.software raids are every bit as capable as hardware raids are and have been for many years now, so why dont you get your head out of your arse and start showing us all some stats on your claims instead of just disrespecting people ???? Put up or shut up my friend and lets see your stats and data to back it up.

I believe this link should clear it up for you.  One thing to also consider is the fact that unless you purchase a new mobo with the same controller it's dam_n near impossible to migrate your software RAID in Windows.  Not so hard in the *nixes.