Is RAID 5 worth it?
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Mike Marynowski wrote:
if you decide to go against my advice
Don't worry. I haven't received a single positive response on software RAID, so I will do what I thought originally: a second hard drive to daily backup the first one with incremental disk images or something like that. My motherboard (AFAIK) is Intel, but again, I might be wrong. Thanks for your suggestion :)
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
Integrated RAID on a motherboard is technically still "hardware" RAID. Software RAID is when you use Windows (or Linux) to manage a RAID array and it does the "logic" for you, instead of a hardware controller. If you are managing your array through Disk Management, its software RAID...if you have to go through a pre-boot BIOS-like interface or a vendor-specific software utility, it's hardware RAID.
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Integrated RAID on a motherboard is technically still "hardware" RAID. Software RAID is when you use Windows (or Linux) to manage a RAID array and it does the "logic" for you, instead of a hardware controller. If you are managing your array through Disk Management, its software RAID...if you have to go through a pre-boot BIOS-like interface or a vendor-specific software utility, it's hardware RAID.
Ok, what I have is hardware RAID integrated into the motherboard, but not with an independent RAID controller, but the main CPU doing it. According to John (in one of his posts above), its performance sucks in Windows OSs.
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
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I will be reinstalling my main PC with Vista x64 this weekend. I took the opportunity to upgrade the RAM and the hard drives. It had a 250 GB hard drive which I am replacing with two 500 GB HDs. I was thinking about going RAID 0 or RAID 1, or maybe just using the second HD for incremental backups. But somewhere deep in my mind a RAID 5 idea appeared. Do anybody of you use RAID 5 in your day-to-day computer? Is it worth it? How is performance? Supposedly, a bit better. What do you recommend?
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
i have done a couple of server with Intel ICH8/9/10 and i can tell you that mainly 9/10 are well worth it... intel has done a good job with this free raid... and also you can't compare this ICH RAID with Software RAID, and neither with hardware controllers... its right in the middle and above a lot of those entry level controllers that you buy... i bought an LSI last year it was a deception i prefer the ICH10 without any doubt... In my personal server i have an Tyan MB with ICH10 and 3x 750gb 7200rpm in RAID 5 and the throughput is around 200mb/s... even my system (Single) SCSI UW320 IBM 74gb 15000 rpm does not go past 74mb/s... Problems until today NONE... the only down its a little slow when checking data for curruption, but that just happens if the power fails or some like that... but you can continue to work at the same time... So i would say go for it... and if you want go for a MB from INTEL(INTEL MAKE AND MODEL NOT ASUS) with ICH10 they are real stable, and very good on performance...
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As the storage space increases it is worthwhile with a couple of caveats: 1. Don't use software (host PC) RAID5. Under any circumstances. 2. Limit the number of drives per array to four, at most five or the array rebuild time is too long. We have a NAS with three arrays, four drives each and our data survived a major water leak from the server room air conditioning system that dissolved the ceiling tiles until they gave way pouring an alkali solution that dissolved lumps of copper off the backplane PCBs. I wasn't very happy. :| Elaine (restrained fluffy tigress)
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on item #2 - note that rebuild times are inversely related to the number of drives. The more drives that you have, the quicker that you can rebuild one from parity. I think about it this way: if I have two drives, each is 1/2 of the data. If I have three, then 1/3. If four, 1/4, etc.
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Ok, what I have is hardware RAID integrated into the motherboard, but not with an independent RAID controller, but the main CPU doing it. According to John (in one of his posts above), its performance sucks in Windows OSs.
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
I think John probably had a buggy driver or something - Windows or not, the controller has to do the same thing. Integrated RAID controllers aren't much slower than cheap dedicated controllers, if at all - both offload XOR calculations to the processor, which means slower write times. You can expect a big boost in read performance though. So, I guess it depends what you are doing. RAID 1 will take a much smaller hit - you should get ALMOST the same read and write performance (EDIT: as a single disk). All my development machines are setup as RAID1. It takes me almost two days to configure a new machine, and I don't want to lose any local "work in progress" before it is backed up to the server. Throwing in a new drive and hitting "rebuild" is a lot easier than reconfiguring a machine from scratch for 20+ hours. The biggest problem with integated/cheap dedicated controllers is the lack of cache memory. Onboard cache will GREATLY increase your write performance since writes go into the high speed memory and get written to disk at a "better time" (idle, once it seeks to the right place, etc). An onboard dedicated XOR processor helps a bit, but any modern processor really doesn't have that much trouble computing 50MB/s of XOR data in the background, so it's not a big deal.
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i have done a couple of server with Intel ICH8/9/10 and i can tell you that mainly 9/10 are well worth it... intel has done a good job with this free raid... and also you can't compare this ICH RAID with Software RAID, and neither with hardware controllers... its right in the middle and above a lot of those entry level controllers that you buy... i bought an LSI last year it was a deception i prefer the ICH10 without any doubt... In my personal server i have an Tyan MB with ICH10 and 3x 750gb 7200rpm in RAID 5 and the throughput is around 200mb/s... even my system (Single) SCSI UW320 IBM 74gb 15000 rpm does not go past 74mb/s... Problems until today NONE... the only down its a little slow when checking data for curruption, but that just happens if the power fails or some like that... but you can continue to work at the same time... So i would say go for it... and if you want go for a MB from INTEL(INTEL MAKE AND MODEL NOT ASUS) with ICH10 they are real stable, and very good on performance...
Everyone else here has adviced me against integrated motherboard RAID. So, you think it can be worth it? Would I get better performance than a single drive? I like the redundancy, but I could as well solve that with daily backups. And RAID 0 I think would be a little dangerous.
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
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I think John probably had a buggy driver or something - Windows or not, the controller has to do the same thing. Integrated RAID controllers aren't much slower than cheap dedicated controllers, if at all - both offload XOR calculations to the processor, which means slower write times. You can expect a big boost in read performance though. So, I guess it depends what you are doing. RAID 1 will take a much smaller hit - you should get ALMOST the same read and write performance (EDIT: as a single disk). All my development machines are setup as RAID1. It takes me almost two days to configure a new machine, and I don't want to lose any local "work in progress" before it is backed up to the server. Throwing in a new drive and hitting "rebuild" is a lot easier than reconfiguring a machine from scratch for 20+ hours. The biggest problem with integated/cheap dedicated controllers is the lack of cache memory. Onboard cache will GREATLY increase your write performance since writes go into the high speed memory and get written to disk at a "better time" (idle, once it seeks to the right place, etc). An onboard dedicated XOR processor helps a bit, but any modern processor really doesn't have that much trouble computing 50MB/s of XOR data in the background, so it's not a big deal.
My idea of the RAID 5 is to get better performance with a little more reliability for a reasonable price. These days I am not doing much development, but still every now and then I do a few complicated SQL queries or builds that take a couple of minutes. So, after a few hours here in CP (and simultaneously in Google) I have learned quite a few things, but still cannot make my mind on whether to go RAID 5 or just a single drive with a daily backup to a second drive. :confused:
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
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Hi John, So I guess I'll go back to my original plan of two 500 GB HDs, using the second one to keep a daily backup of the first (for me 500 GB is more than enough). That's why I love this place!! Every time I have a question, someone who really knows about gives me a better answer than Google. Thanks!! :-D
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
In my experience RAID5 is not worth having if its implemented in software under Windows, too slow. I use a 146G Seagate Cheetah as my system drive. I keep data on two 500G Seagate Barracudas which are striped and I have a similar drive housed externally onto which I do hourly selective incremental backups I'm feel more secure with this arrangement than I did with a 3 disk software Raid 5 array, and I get better performance.
Multi famam, conscientiam pauci verentur.(Pliny)
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I will be reinstalling my main PC with Vista x64 this weekend. I took the opportunity to upgrade the RAM and the hard drives. It had a 250 GB hard drive which I am replacing with two 500 GB HDs. I was thinking about going RAID 0 or RAID 1, or maybe just using the second HD for incremental backups. But somewhere deep in my mind a RAID 5 idea appeared. Do anybody of you use RAID 5 in your day-to-day computer? Is it worth it? How is performance? Supposedly, a bit better. What do you recommend?
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
Tried to build it twice, both times gave up due to controller and disk problems. According to what I learned on the internet: 3 disks doesn't work very well - performance wise and other. Someone (who seemed to work with it a lot) said something about "at least 5 disks". Also, RAID controllers still seem to insist on rebuilding the entire disk when it fails once. However, relative failure rates haven't gone down at the same speed capacities have gone up, so with todays amounts of data, rebuilds happen much more frequent. Also, multiple disk fails aren't that unlikely (compared to single disk fails). The most prominent reason is a failing power supply. Due to all of this, I ended up using a software(!) RAID 0 coupled with a daily robocopy to an external disk with its own power supply. It isn't that much of a racer, but keeps a system on older disks (2x 80GB SAMSUNG) build time competetive with some of the newer machines around. I haven't run into any (obvious) problems with data loss yet. (not the newest though - building on 4 cores 15 minutes for both configurations. I am jealous!)
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Do NOT use RAID5 on an nVidia motherboard - it is well known that their implementation can't be trusted. Perhaps they got it right now, but as of the 6 months old firmware it still wasn't working properly. Many other people have had the same experience as I. Do yourself a favor - if you decide to go against my advice, try "faking" a few failure scenarios and see what happens before you trust critical data with it. My nForce 680i board corrupted many files when a drive gave out...exactly what RAID5 is supposed to prevent. It's very easily reproducable...if I unplug a SATA connector from a live drive in system...system freezes (that's OK, although not ideal) and next boot, windows will yell about corrupted files...woohoo... nVidia seems to works well in drive pairs though (mirroring or striping). Just another reason to stick to Intel boards next time...
I second that NVIDIA Mobo's and RAID do not go together. I had a system with 4 raided raptors which should have been lightning fast. It was only marginally faster than a single drive bu8t Vista (Grrrrr) would fail completly every 3 months or so. The Mobo was a rather expensive one as well. The system runs perfectly now with Win7 and a single 500GB drive. Raptors went on fleabay. :laugh:
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I will be reinstalling my main PC with Vista x64 this weekend. I took the opportunity to upgrade the RAM and the hard drives. It had a 250 GB hard drive which I am replacing with two 500 GB HDs. I was thinking about going RAID 0 or RAID 1, or maybe just using the second HD for incremental backups. But somewhere deep in my mind a RAID 5 idea appeared. Do anybody of you use RAID 5 in your day-to-day computer? Is it worth it? How is performance? Supposedly, a bit better. What do you recommend?
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
Thought RAID 5 was 3 or more disks - so if you have two it wouldn't apply! i.e RAID 0 or 1 available (?) RAID 0 For speed and suicide jocks only i.e. gamers! RAID 1 More reliable in that if one goes down you can continue but loose half your capacity and you still need to backup (burnt or stolen computer etc) For development/general machines I don't bother with raid - just backup to external drives For Web Servers use RAID 1 (with hardware controller) - this means if one drive fails system will continue (don't like having to get up early!). Backup still required of course :)
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HDs are so cheap these days that I'll just get one more to give RAID 5 a try. Thanks!
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
You need at least 3 drives for a RAID-5, but, as the mighty tigress has stated, better get 4, so you have at least one replacement in stock. Just saying.
Cheers, Sebastian -- "If it was two men, the non-driver would have challenged the driver to simply crash through the gates. The macho image thing, you know." - Marc Clifton
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Everyone else here has adviced me against integrated motherboard RAID. So, you think it can be worth it? Would I get better performance than a single drive? I like the redundancy, but I could as well solve that with daily backups. And RAID 0 I think would be a little dangerous.
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
if you want a faster and reliable system you go with RAID 5 3 hdd is OK and it works just fine... if you want just the redundancy go with raid 1 but no performance gain... if you want just the performance go with raid 0, but your risks double... as if one the hdd goes bad you loose information of both... intel ICH configuration has only 4 or 5 options on the menu... i dont know how some people can have problems... its a straight process... you chose the hdd's and raid type then you create the volume exit and its done... To enter the config you press CTRL+I on boot when it shows on the screen. dont forget if you are using 2003 server or xp you may have to use the driver disk to add the raid controller driver to windows setup so it recognizes the drive. on vista you dont have this problem it comes with the driver already... After intalling windows you can install Intel® Matrix Storage Manager it gives you all the info... and also alerts you and shows the status of the hdd's and raid as when rebuild... About the backups, having redundancy doesn't avoid Backups... You should do backups anyway... the intention is UPTIME and RELIABILITY not avoid backups.... maybe you can change your backup policy a lit but continue making backups from time to time... you can have some kind of power issues that burn all your hdd and if you dont have backup you are in trouble...
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I will be reinstalling my main PC with Vista x64 this weekend. I took the opportunity to upgrade the RAM and the hard drives. It had a 250 GB hard drive which I am replacing with two 500 GB HDs. I was thinking about going RAID 0 or RAID 1, or maybe just using the second HD for incremental backups. But somewhere deep in my mind a RAID 5 idea appeared. Do anybody of you use RAID 5 in your day-to-day computer? Is it worth it? How is performance? Supposedly, a bit better. What do you recommend?
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
It is only worth it if you are willing to drop the fu$$ies to do it right! I have a hardware card from Adaptec and a 5-disk Intel hot-swap SCSI cage in my PC. OK, so I am a bit extreme... but... Motherboard RAID? Can't be trusted, in my opinion. Better than nothing, but... In the case of my RAID 5 of 320 SCSIs, it works well. Much less wait for Windows Explorer or the like when I am in a multitasking frenzy! Data seems to move a LOT faster that single drive. I have not benchmarked with RAID 0/1/5 or anything, but just know that if you drop the cash, at least one guy is happy with the results! kc
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Thought RAID 5 was 3 or more disks - so if you have two it wouldn't apply! i.e RAID 0 or 1 available (?) RAID 0 For speed and suicide jocks only i.e. gamers! RAID 1 More reliable in that if one goes down you can continue but loose half your capacity and you still need to backup (burnt or stolen computer etc) For development/general machines I don't bother with raid - just backup to external drives For Web Servers use RAID 1 (with hardware controller) - this means if one drive fails system will continue (don't like having to get up early!). Backup still required of course :)
Bob1000 wrote:
Thought RAID 5 was 3 or more disks - so if you have two it wouldn't apply!
Yes, I know. I currently have two disks but am thinking about getting a third one to go RAID 5. This discussion is leading me nowhere. I've learned a lot, but since there are people for and against it, I think I will do my own testing and see how it works :) Thanks everybody for your tips!! :)
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
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I will be reinstalling my main PC with Vista x64 this weekend. I took the opportunity to upgrade the RAM and the hard drives. It had a 250 GB hard drive which I am replacing with two 500 GB HDs. I was thinking about going RAID 0 or RAID 1, or maybe just using the second HD for incremental backups. But somewhere deep in my mind a RAID 5 idea appeared. Do anybody of you use RAID 5 in your day-to-day computer? Is it worth it? How is performance? Supposedly, a bit better. What do you recommend?
Luis Alonso Ramos Intelectix Chihuahua, Mexico My Blog!
I have an xfx nforce motherboard. I use the onboard RAID 5 (2 x 250GB striped 1 x 500GB mirror). It's seek times, and read write throughput are slightly better than a single drive. One thing that is important to mention that I don't think anyone else has so far: The stripped drives should be the same model HD. If you are scrounging a bunch of HD's together that have been laying around and try to make a RAID 5 it's not going to work to well. RAID 0 sure, but any of the RAID levels that deal with parity should be on identical drives (for the striping anyway). Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level. Software RAID is using the compmgmt.msc's Disk Management(local) Snap-in to create a RAID array. While the performance of RAID5, on my motherboard, isn't going to beat a $600 controller, it isn't the same as Software RAID. Think of onboard graphics cards, at the hardware level they use some RAM and they use some CPU cycles, but they aren't doing "software rendering" (which if anybody HAS used before is way way way worse than an onboard graphics card). In the end, my system isn't screaming speed, but it isn't slow either and all of my data is backed up against a hard drive failing, for my important stuff that I can't loose, I FTPS it off site (the only protection against fire, flood, theft of equipment, data corruption, etc). Well that's my two cents anyway. :zzz: :zzz: :zzz:
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if you want a faster and reliable system you go with RAID 5 3 hdd is OK and it works just fine... if you want just the redundancy go with raid 1 but no performance gain... if you want just the performance go with raid 0, but your risks double... as if one the hdd goes bad you loose information of both... intel ICH configuration has only 4 or 5 options on the menu... i dont know how some people can have problems... its a straight process... you chose the hdd's and raid type then you create the volume exit and its done... To enter the config you press CTRL+I on boot when it shows on the screen. dont forget if you are using 2003 server or xp you may have to use the driver disk to add the raid controller driver to windows setup so it recognizes the drive. on vista you dont have this problem it comes with the driver already... After intalling windows you can install Intel® Matrix Storage Manager it gives you all the info... and also alerts you and shows the status of the hdd's and raid as when rebuild... About the backups, having redundancy doesn't avoid Backups... You should do backups anyway... the intention is UPTIME and RELIABILITY not avoid backups.... maybe you can change your backup policy a lit but continue making backups from time to time... you can have some kind of power issues that burn all your hdd and if you dont have backup you are in trouble...
xpto05 wrote:
if you want a faster and reliable system you go with RAID 5 3 hdd is OK and it works just fine...
Even with motherboard RAID, will it be slightly faster than a single disk??
xpto05 wrote:
About the backups, having redundancy doesn't avoid Backups
Yes, I know. I plan on backing up to an external drive anyway. Thanks!! :)
Luis Alonso Ramos Intelectix Chihuahua, Mexico Follow me on Twitter (@luisalonsoramos) or on my blog (www.luisalonsoramos.com)!
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I have an xfx nforce motherboard. I use the onboard RAID 5 (2 x 250GB striped 1 x 500GB mirror). It's seek times, and read write throughput are slightly better than a single drive. One thing that is important to mention that I don't think anyone else has so far: The stripped drives should be the same model HD. If you are scrounging a bunch of HD's together that have been laying around and try to make a RAID 5 it's not going to work to well. RAID 0 sure, but any of the RAID levels that deal with parity should be on identical drives (for the striping anyway). Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level. Software RAID is using the compmgmt.msc's Disk Management(local) Snap-in to create a RAID array. While the performance of RAID5, on my motherboard, isn't going to beat a $600 controller, it isn't the same as Software RAID. Think of onboard graphics cards, at the hardware level they use some RAM and they use some CPU cycles, but they aren't doing "software rendering" (which if anybody HAS used before is way way way worse than an onboard graphics card). In the end, my system isn't screaming speed, but it isn't slow either and all of my data is backed up against a hard drive failing, for my important stuff that I can't loose, I FTPS it off site (the only protection against fire, flood, theft of equipment, data corruption, etc). Well that's my two cents anyway. :zzz: :zzz: :zzz:
Member 4611134 wrote:
Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level.
I will guarantee that it is not a hardware controller. It is just a plain old SATA controller with a bios that can boot create and off the array and a driver that in windows does the software raid. If it were a true hardware controller it would contain a dedicated raid cpu of 200 MHz to 1GHz with an external cache and external battery pack (that is larger than a cell phone battery) to supply hold cache memory in the event of a power outage. After the power is restored this cache gets flushed to the disks.
John
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I have an xfx nforce motherboard. I use the onboard RAID 5 (2 x 250GB striped 1 x 500GB mirror). It's seek times, and read write throughput are slightly better than a single drive. One thing that is important to mention that I don't think anyone else has so far: The stripped drives should be the same model HD. If you are scrounging a bunch of HD's together that have been laying around and try to make a RAID 5 it's not going to work to well. RAID 0 sure, but any of the RAID levels that deal with parity should be on identical drives (for the striping anyway). Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level. Software RAID is using the compmgmt.msc's Disk Management(local) Snap-in to create a RAID array. While the performance of RAID5, on my motherboard, isn't going to beat a $600 controller, it isn't the same as Software RAID. Think of onboard graphics cards, at the hardware level they use some RAM and they use some CPU cycles, but they aren't doing "software rendering" (which if anybody HAS used before is way way way worse than an onboard graphics card). In the end, my system isn't screaming speed, but it isn't slow either and all of my data is backed up against a hard drive failing, for my important stuff that I can't loose, I FTPS it off site (the only protection against fire, flood, theft of equipment, data corruption, etc). Well that's my two cents anyway. :zzz: :zzz: :zzz:
Member 4611134 wrote:
Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level. Software RAID is using the compmgmt.msc's Disk Management(local) Snap-in to create a RAID array. While the performance of RAID5, on my motherboard, isn't going to beat a $600 controller, it isn't the same as Software RAID.
Unless you paid a several hundred dollar premium (over an otherwise identical but nonraid version of the board) it's not hardware raid, even thought your mobo (or a cheap "raid card") has a "raid controller chip" on it. Real hardware raid has either a microcontroller or asic to do all the parity calculations. Fake hardware raid has a chip that says "I'm a raid controller" but offloads 100% of the work to the CPU just like pure software raid. This results in something as slow as software raid, but which is also tied to a specific controller. Pure software raid at least has the advantage of being portable. :doh:
It is a truth universally acknowledged that a zombie in possession of brains must be in want of more brains. -- Pride and Prejudice and Zombies
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Member 4611134 wrote:
Also note, in my board (which cost much much less than $600) RAID is indeed implemented at the hardware level.
I will guarantee that it is not a hardware controller. It is just a plain old SATA controller with a bios that can boot create and off the array and a driver that in windows does the software raid. If it were a true hardware controller it would contain a dedicated raid cpu of 200 MHz to 1GHz with an external cache and external battery pack (that is larger than a cell phone battery) to supply hold cache memory in the event of a power outage. After the power is restored this cache gets flushed to the disks.
John
Using motherboard raid (RAID 5 2x250GB 1X500GB) : Random Access : 10.3 ms Average Read : 96MB/s Single SATA Drive (500GB): Random Access : 12.4 ms Average Read : 88.5MB/s So in my situation, for whatever reason, a single drive is in no way faster.