RAID Card

[chrisprice12]

Hey,

 

I was just wondering if someone could tell me the benefits of using a RAID card over the motherboard RAID. I'm building a server and plan on using RAID. Also, how do you configure a RAID array with a card? Is it software based? Or do you still do it in the UEFI as normal?

 

How do they work? I'm assuming its a PCI(e) card which has so many SATA ports available, and you connect your drives to that. Do you connect any non-RAID drives to it?

 

Can you monitor SMART status with a RAID card? 

 

I also heard that if you make use of a RAID card you can take that RAID array anywhere, provided you have the drives as well. Is this true?

 

Thanks for any info, just looking to increase my knowledge further first.

 

Chris

[leadeater]

Hardware RAID cards offer much greater performance than motherboard RAID for parity configurations such as RAID 5/6, so long as you buy a higher end model with the battery unit to allow write-back cache.

 

RAID cards have their own BIOS which you will get a prompted when booting. In this you can configure RAID arrays, view/configure properties of the card, view HDDs etc.

 

RAID cards also have software to configure and monitor them in OS, LSI MegaRAID Manager for example.

 

RAID cards monitor health of disks themselves and will warn you about failing disks, you can view this health status in the RAID software. Most have an alarm, very loud, that will sound if a disk fails.

 

Yes you can move the card between systems.

 

Keep in mind there are plenty of software options available now days so you don't have to use a RAID card.

[T0242]

Most of the variables are based on the card you get;

I have a pretty old card in my server right now, I don't even use hardware raid, but I think I can get the SMART status from my disks.

 

They basically make you able to use storage devices over PCI-e (most likely)

They often add themselves to the boot order of your machine (just like a NIC with PXE) (meaning you can boot from them)

 

Could you please explain "non raid drives" though?

 

I mean you can set up the arrays depending on the card you get and most likely you can also leave drives out of your raid array and use them a separate disks.

 

Raid cards mainly are used for expanding IO on servers or for allowing things like hot swap (correct, motherboards can also support this, but doing this on a completely separate card that is 100% set to hot swap means that you can't really do anything wrong by disconnecting any of the drives), Often raid cards are used for RAID 5/6 Arrays for this reason (redundancy and performance are both favoured in this type of array).

 

But mainly: Expanding IO and adding busses that are not natively on the motherboard (SAS (SAS is the faster "brother" of sata, you can hook up SATA drives to a SAS card without a problem, the other way around this doesn't work though.))

[Electronics Wizardy]

Don't use mobo raid, its not really raid, its just telling the os, that they are to be used in raid. The calculations are done on the cpu.

 

For config, you can press a key at bootup(like ctrl h) or use a software in linux/windows.

 

Its normally a pcie card, with a sas port(external or internal). You can then connect that to drives or expanders. Normally they have a max of something like 128 drives percontroller.

 

A raid card normally has its own cpu(lsi is using IBM power cpu's with normally 1g cache).

 

Depends on the system, for servers, all drives go to the raid card.

 

SMART depends on the card, but most will warn when a drive is going bad.

 

Normally if you make a array on a lsi card, you can use it on any lsi card.

[scottyseng]

15 minutes ago, chrisprice12 said:

-snip-

Good RAID cards with oncard batteries have much better RAID6 and RAID5 performance. They're usually much faster overall than onboard RAID. They also feature their own RAM / processors, they are like mini PCs dedicated to RAID. If the power goes out, they have a oncard battery so your data on the RAID card RAM cache does not get lost (Do note, this is different from a UPS unit. This protects you if you happen to need to force shutdown the server or if the PSU dies).

 

It depends on the RAID card, but with LSI, you can use the software MegaRAID storage manager and it makes making arrays / managing them really easy.

 

It's a PCIe (usually x8) card that can feature one SAS port (four lanes), two SAS ports (eight lanes), or even more (Costs more though). Do note if you want to use SATA devices on a RAID card with SAS ports, you will need a break out cable to convert to SAS. In general, one SAS port = 4 SATA ports. However, with SAS, you can buy SAS expanders and expand the RAID card to even more devices (Most RAID cards support up to 128 drives or more). Finally depending on the server chassis you have, some have built in LSI SAS expanders already. My SuperMicro chassis only needs one or two SAS input to run all 24 drive bays and can break out to even more.

 

Sadly it depends on the card. Some show more or less data about the drive. It will warn you / flat out tell you a drive is dead though.

 

Yeah, if you have a LSI RAID array, you can usually move it to a different LSI card. Unless you mean take the whole card / RAID drives to another PC, which you can do. I've shuffled my RAID array between my desktop and PC several times when I was migrating data.

 

Finally, as stated above, there's a lot of good software only RAID like solutions these days. You don't have to shove out several hundred dollars for a RAID card these days and it is overkill for home use (Depends on how small the array is). I would know because I bought a LSI RAID card for a four drive RAID10 array (Before I was on the forums, I thought a RAID card was the only way)...these days, there's a lot of comparable great software solutions to save you some money.

[leadeater]

Here's an example picture of an IBM M5110 with cache upgrade and BBU.

 

[Electronics Wizardy]

2 minutes ago, leadeater said:

Here's an example picture of an IBM M5110 with cache upgrade and BBU.

 

Im assuimng thats a lsi rebrand, like the dell's and the HP's

[leadeater]

Just now, Electronics Wizardy said:

Im assuimng thats a lsi rebrand, like the dell's and the HP's

Yep, however HP now use PMC Adaptec.

[chrisprice12]

20 minutes ago, leadeater said:

Hardware RAID cards offer much greater performance than motherboard RAID for parity configurations such as RAID 5/6, so long as you buy a higher end model with the battery unit to allow write-back cache.

 

RAID cards have their own BIOS which you will get a prompted when booting. In this you can configure RAID arrays, view/configure properties of the card, view HDDs etc.

 

RAID cards also have software to configure and monitor them in OS, LSI MegaRAID Manager for example.

 

RAID cards monitor health of disks themselves and will warn you about failing disks, you can view this health status in the RAID software. Most have an alarm, very loud, that will sound if a disk fails.

 

Yes you can move the card between systems.

 

Keep in mind there are plenty of software options available now days so you don't have to use a RAID card.

What about say RAID 10, just for example? Is it worth always getting a RAID card or only if you plan on using elegant RAID solutions?

 

That makes sense! So you set the boot priority to the card, and then you can configure it from there when it loads itself up?

 

Ok, so to add another question...software RAID vs mobo RAID?

 

Thanks for your help!

[chrisprice12]

22 minutes ago, T0242 said:

Most of the variables are based on the card you get;

I have a pretty old card in my server right now, I don't even use hardware raid, but I think I can get the SMART status from my disks.

 

They basically make you able to use storage devices over PCI-e (most likely)

They often add themselves to the boot order of your machine (just like a NIC with PXE) (meaning you can boot from them)

 

Could you please explain "non raid drives" though?

 

I mean you can set up the arrays depending on the card you get and most likely you can also leave drives out of your raid array and use them a separate disks.

 

Raid cards mainly are used for expanding IO on servers or for allowing things like hot swap (correct, motherboards can also support this, but doing this on a completely separate card that is 100% set to hot swap means that you can't really do anything wrong by disconnecting any of the drives), Often raid cards are used for RAID 5/6 Arrays for this reason (redundancy and performance are both favoured in this type of array).

 

But mainly: Expanding IO and adding busses that are not natively on the motherboard (SAS (SAS is the faster "brother" of sata, you can hook up SATA drives to a SAS card without a problem, the other way around this doesn't work though.))

Sorry, I meant drives you don't intend to be part of the RAID.

 

How do you hook up SATA to SAS? Does the connector interchange?

 

Thanks for the advice, really helpful.  

[chrisprice12]

25 minutes ago, Electronics Wizardy said:

Don't use mobo raid, its not really raid, its just telling the os, that they are to be used in raid. The calculations are done on the cpu.

 

For config, you can press a key at bootup(like ctrl h) or use a software in linux/windows.

 

Its normally a pcie card, with a sas port(external or internal). You can then connect that to drives or expanders. Normally they have a max of something like 128 drives percontroller.

 

A raid card normally has its own cpu(lsi is using IBM power cpu's with normally 1g cache).

 

Depends on the system, for servers, all drives go to the raid card.

 

SMART depends on the card, but most will warn when a drive is going bad.

 

Normally if you make a array on a lsi card, you can use it on any lsi card.

I see what you mean, thanks for your help!

[chrisprice12]

32 minutes ago, scottyseng said:

Good RAID cards with oncard batteries have much better RAID6 and RAID5 performance. They're usually much faster overall than onboard RAID. They also feature their own RAM / processors, they are like mini PCs dedicated to RAID. If the power goes out, they have a oncard battery so your data on the RAID card RAM cache does not get lost (Do note, this is different from a UPS unit. This protects you if you happen to need to force shutdown the server or if the PSU dies).

 

It depends on the RAID card, but with LSI, you can use the software MegaRAID storage manager and it makes making arrays / managing them really easy.

 

It's a PCIe (usually x8) card that can feature one SAS port (four lanes), two SAS ports (eight lanes), or even more (Costs more though). Do note if you want to use SATA devices on a RAID card with SAS ports, you will need a break out cable to convert to SAS. In general, one SAS port = 4 SATA ports. However, with SAS, you can buy SAS expanders and expand the RAID card to even more devices (Most RAID cards support up to 128 drives or more). Finally depending on the server chassis you have, some have built in LSI SAS expanders already. My SuperMicro chassis only needs one or two SAS input to run all 24 drive bays and can break out to even more.

 

Sadly it depends on the card. Some show more or less data about the drive. It will warn you / flat out tell you a drive is dead though.

 

Yeah, if you have a LSI RAID array, you can usually move it to a different LSI card. Unless you mean take the whole card / RAID drives to another PC, which you can do. I've shuffled my RAID array between my desktop and PC several times when I was migrating data.

 

Finally, as stated above, there's a lot of good software only RAID like solutions these days. You don't have to shove out several hundred dollars for a RAID card these days and it is overkill for home use (Depends on how small the array is). I would know because I bought a LSI RAID card for a four drive RAID10 array (Before I was on the forums, I thought a RAID card was the only way)...these days, there's a lot of comparable great software solutions to save you some money.

Thanks for the information. Everyone seems to be going on about LSI, is this the best company for RAID cards?

 

I'm glad you mentioned that, I would have been getting a 4 port SAS just to compensate for 4 SATA drives Yeah I was going to grab a rack mountable chassis. 

 

Do you think its worth it then? I would probably be doing something similar to you - I was thinking RAID 10 but not so sure after some thought. Wasn't going to be a massive thing. Just wanted to make sure I was doing it properly instead of cheaping out now, and realising I should probably get one later down the line.

 

Cheers for the help  

[chrisprice12]

44 minutes ago, leadeater said:

Here's an example picture of an IBM M5110 with cache upgrade and BBU.

 

That's quite helpful, thanks!

[T0242]

30 minutes ago, chrisprice12 said:

How do you hook up SATA to SAS? Does the connector interchange?

Well, the SAS interface uses almost the same connector as SATA

 

However for sata you know how you have those 2 connectors (one for power and one for data), on sas that is one connector (the pins are in the same location and such), but since that is one large connector there isn't a little space in-between to fit a SATA connector on there (and SATA isn't compatible with SAS drives), but when you plug in a SAS connector on a SATA Disk it will work.

 

Here are some graphics that demonstrate this I found on the internet (as it currently is dark and I am on my bed with my laptop ;p)

 

SATA:

 

SAS:

 

Sorry about the images being rotated

 

But the sas interface can also work on different connectors I think (I think you can see this as your network connection, over RJ45, or SFP, one can have more capabilities than the other but it is the same thing, I think the interface I pointed out is being used on 99.999% of all sas Disks though!)

 

The SAS connector (on the raid card side) will fit on the SATA disk and will work, but putting a SATA cable on the SAS connector will not work due to the little blocked part in the middle

 

EDIT:

 

I also have a raid card in my server, it has a LSI chip on it, and I have a few disks hooked up to it:

 

0:27, its the card with the blue cables coming out (I might get a better video of that soon!)

 

On my specific raid card there is a led blinking and that is because there is no battery backup hooked up to the raid card (meaning that a power outage might ruin a lot of my data at the moment.) Everything is behind a UPS though so it should be fine.

 

In my case this connector is being used to hook the SAS drives up to the raid card

 

(also another unoriginal image form the internet, sorry)

That connector is being used on the raid card side, and the SAS connector I showed before is on the disk side (on the disk itself actually.)

 

 

 

[scottyseng]

8 minutes ago, chrisprice12 said:

-snip-

Well, they're the most known. A lot of other manufacturers (Intel included) buy their RAID chips and just rebrand them as their own. They also make great RAID cards.

 

Yeah, SAS can break out into a lot of drives, a lot, from a single port or two port SAS RAID card.

 

Hmm, I would say if you're doing RAID10, depending on how many drives, I'd probably go software. That being said, you should really consider RAID6 over RAID10. I switched to RAID6 for increased space. RAID10 and RAID6 both can lose two drives, but with RAID6, it can be any two. With RAID10, it has to be the right two drives. If you kill two drives that are the mirror of each other, the RAID array fails.

 

Another major issue to consider with RAID10 is that on RAID cards, you cannot expand a RAID10 array in the future. You might to suck it up and buy a lot more drives to make the new larger array without using the drives you had. You can expand RAID5/6 however.

 

Finally, you will need proper cooling for these RAID cards. They do run hot / need airflow to keep cool. Please do not attempt to remove a RAID card from a PC if you know it was under full load / doesn't have a lot of airflow. You will get pretty bad burns if you touch the heatsink.

[chrisprice12]

On 26/12/2016 at 1:03 AM, T0242 said:

Well, the SAS interface uses almost the same connector as SATA

 

However for sata you know how you have those 2 connectors (one for power and one for data), on sas that is one connector (the pins are in the same location and such), but since that is one large connector there isn't a little space in-between to fit a SATA connector on there (and SATA isn't compatible with SAS drives), but when you plug in a SAS connector on a SATA Disk it will work.

 

Here are some graphics that demonstrate this I found on the internet (as it currently is dark and I am on my bed with my laptop ;p)

 

SATA:

 

SAS:

 

Sorry about the images being rotated

 

But the sas interface can also work on different connectors I think (I think you can see this as your network connection, over RJ45, or SFP, one can have more capabilities than the other but it is the same thing, I think the interface I pointed out is being used on 99.999% of all sas Disks though!)

 

The SAS connector (on the raid card side) will fit on the SATA disk and will work, but putting a SATA cable on the SAS connector will not work due to the little blocked part in the middle

 

EDIT:

 

I also have a raid card in my server, it has a LSI chip on it, and I have a few disks hooked up to it:

 

0:27, its the card with the blue cables coming out (I might get a better video of that soon!)

 

On my specific raid card there is a led blinking and that is because there is no battery backup hooked up to the raid card (meaning that a power outage might ruin a lot of my data at the moment.) Everything is behind a UPS though so it should be fine.

 

In my case this connector is being used to hook the SAS drives up to the raid card

 

(also another unoriginal image form the internet, sorry)

That connector is being used on the raid card side, and the SAS connector I showed before is on the disk side (on the disk itself actually.)

 

 

 

Wow, that was really helpful. Thanks for the video. Just another question though, you can have a RAID array and still have a standard disk connected outside of the RAID can't you?

[chrisprice12]

On 26/12/2016 at 1:15 AM, scottyseng said:

Well, they're the most known. A lot of other manufacturers (Intel included) buy their RAID chips and just rebrand them as their own. They also make great RAID cards.

 

Yeah, SAS can break out into a lot of drives, a lot, from a single port or two port SAS RAID card.

 

Hmm, I would say if you're doing RAID10, depending on how many drives, I'd probably go software. That being said, you should really consider RAID6 over RAID10. I switched to RAID6 for increased space. RAID10 and RAID6 both can lose two drives, but with RAID6, it can be any two. With RAID10, it has to be the right two drives. If you kill two drives that are the mirror of each other, the RAID array fails.

 

Another major issue to consider with RAID10 is that on RAID cards, you cannot expand a RAID10 array in the future. You might to suck it up and buy a lot more drives to make the new larger array without using the drives you had. You can expand RAID5/6 however.

 

Finally, you will need proper cooling for these RAID cards. They do run hot / need airflow to keep cool. Please do not attempt to remove a RAID card from a PC if you know it was under full load / doesn't have a lot of airflow. You will get pretty bad burns if you touch the heatsink.

I appreciate that info, really helpful. How do you find RAID 6 in terms of speed? I was after both decent speeds and redundancy, thus why I chose RAID 10. You can lose any one drive in RAID 10 though can't you? I'll most likely be using four 3tb WD Red drives, which would give me 12tb, with a RAID 10, 6tb.

 

Just to lead on to another question - I was also looking at the Red Pro's, that is 7200rpm. Does this make a huge difference in a RAID array? Is it worth sticking the extra money upfront for the drives?

 

Thanks for your help!

[scottyseng]

8 minutes ago, chrisprice12 said:

Wow, that was really helpful. Thanks for the video. Just another question though, you can have a RAID array and still have a standard disk connected outside of the RAID can't you?

If by this you mean have a normal drive connected to the RAID card that's not in a RAID array, then no. There's no pass through for RAID cards. You'd have to make a single disk RAID0 or plug the drive directly to the motherboard (Which is how my OS SSD is).

 

RAID6 was faster in sequential (large file) transfers for me, by a notable amount than RAID10. RAID10 I would reserve for special cases such as a lot of financial data / VMs or programs that need a lot of random IO. You can lose any one drive in RAID10, correct. It's the second drive that fails you have to worry about.

 

Hmm, I had four WD Red 4TB in RAID10 before, they got 350MB/s read and write for sequential. For six of them, I got 500MB/s.

 

No, I would not pay up that much more for WD Red Pros. There's not enough speed difference to outweigh the cost. I have a WD 4TB Re drive and compared to my WD Reds, they're about 20-30MB/s slower, but still, the Reds get 150MB/s per drive.