Mirroring Controllers - What have been Your Experiences?

Today's installment is a lengthy (but hopefully informative) piece on mirroring controllers. Ever had weird problems with a FastTrack TX2000? Are you curious how well HighPoints RocketRAID boards are really supported? Ever wondered which controller gives you the best performance for every dollar spent? In true Slashdot tradition, we're taking the issue and throwing it out to you, the readers. Futurepower(R) is willing to start us off with a wealth of information on his experiences, and I'm hoping a few of you are willing to do the same. Futurepower(R) asks: "What experiences, both good and bad, have you had with mirroring controllers? Are there manufacturers I haven't found?

For those who are interested but don't have experience, mirroring controllers (RAID 1) provide several advantages:

1. They prevent data loss when a hard drive fails. The other drive in the mirror takes over seamlessly.
2. Reading of data is considerably faster since the controller reads the data from the drive that has a head closest to the data.
3. You always have a full hard disk backup that you can pull from your system at any time, such as before installing new software.
4. You can clone a Windows XP drive using the RAID card, and you will have a bootable copy. This is valuable, since the Windows XP file system cannot copy all of its own files. (Don't flame this; it has been verified many times by Microsoft employees, who often suggest using the third-party tools.)

I've found four manufacturers that make inexpensive mirroring controllers:

1. Promise Technology's FastTrak TX2000 is available for about $85 delivered.
2. HighPoint's RocketRAID 133 costs about $80.
3. ACARD Technology's AEC-6880 costs about about $85. Froogle found only one vendor. That's scary.
4. Adaptec makes the ATA RAID 1200A, which is available for about $59 before delivery charges.

As you can see, these controllers cost from $59 to $85. Last weekend Fry's was selling a retail boxed 1800 MHz Athlon XP processor with fan included and an ECS motherboard for $59 total. So $80 seems like a lot for a little card with one chip and a flash ROM.

ECS (EliteGroup) has made 11 motherboards with on-board RAID mirroring controllers. One of them, the P4VXAD, has a Promise controller and costs about $52. What's that about? Employees at Fry's tell me that ECS has the poorest quality control of any of the motherboard manufacturers that they sell. To me, ECS motherboards seem to have surprisingly high quality. However, we have only tested three, and only one extensively.

Silicon Image makes, or made, their 0680 RAID chipset, and Koutech Systems sells the IOFLEX-Pir133 using that chipset. It costs $25 retail. I tried a Koutech card and had a lot of trouble with it, even after updating the BIOS. I talked to an application engineer at Silicon Image and a manager there. I was told that SI bought the technology from another company, and apparently it is no longer supported, doesn't work well, and the company does not intend to put more money into it. I found that the Koutech card corrupts files. The card gives a Stop 07B error when going into the Windows XP Recovery Console, unless the driver is loaded by hand, every time. I lost a lot of time with a product that apparently should not be sold.

My experience with mirroring controllers is mostly with those from Promise Technology. I've been using Promise mirroring controllers since they began making them.

The good about Promise:

1. Promise has been selling RAID 1 controllers a long time. They work.
2. Promise controllers can clone a hard drive quickly.
3. Now some motherboards have Promise mirroring chipsets. You can get the entire motherboard with the Promise controller on the board, for maybe $50 more than the Promise controller card alone.
4. Linux drivers are available. The web site says, "Windows XP/2000/NT4/Me/9x; Novell NetWare 4.1x/5.x; RedHat Linux 7.0/7.1/7.2; TurboLinux Server 6.5; TurboLinux Workstation 7; SuSE Linux 7.2; OpenLinux 3.1" Does that mean that later versions of Linux can't use this card, or did Promise forget to update the brochure PDF file?
5. Promise controllers work fine under DOS, but there is no error reporting if for some reason the mirror breaks.

The disadvantages with Promise, in my opinion:

1. Promise mirroring controllers have a software feature called "sychronization". I've asked many times over the years why it is necessary, since mirrored hard drives should be synchronized 100% of the time. I've never gotten an answer. Recently I've been told by Promise technical support people not to use synchronization, since it has caused problems. It sounds like some technical problem is being hidden.
2. Promise does not support their oldest mirroring controllers under Windows XP. This is a problem since there are many business computers that are used for data entry. A Pentium II is as fast as is necessary. Windows 98 is stable with only one program running. Now those computers need to be converted to Windows XP, since Microsoft has declared that its operating systems have a curious quality: They die. (According to Microsoft, it doesn't matter that at least 100,000,000 people are using Windows 98 worldwide, it came to the end of its life on "30-Jun-2003".)
   
   So, it is necessary to buy another controller for old data entry systems. Notice that Microsoft and Promise could decide to play this game again, and I would like to avoid the second round of buying and installing even another controller. I'd like to find a company that continues to support its products.
   
   The speed of computers used for data entry does not matter, but the security of the data does. Hard drive failures are becoming rare, but a hard drive failure can cause a lot of problems on a data entry computer, so mirroring is required.
3. Some Promise controllers, especially those on motherboards, take a long time to boot. Dots crawl across the screen even if no drives are connected to the controller. Is keeping the Promise name on the screen a time-wasting sales message from Promise? Recently Promise released a BIOS upgrade for some of its cards that reduced the dot-crawling time. However, there is apparently no upgrade for Promise controllers on motherboards.
4. About 2 months after I reported problems, Executive Software said they found a bug in their Diskeeper defragmentation software that might cause data corruption when used with Promise controllers. They said everyone using Diskeeper should upgrade to the new, free, minor version. I've seen no problems since then.
5. Promise Technology's sales literature can be disgusting. This is the second sentence in Promise's description of the FastTrak TX2000: "The FastTrak TX2000 ATA RAID card supports Ultra ATA/133 drives to rock workstations and boost small (or large) office servers like never before." To me, this is obviously written by someone who knows nothing about the product and doesn't care.
6. I find the abundant use of PDF files and unnecessary JavaScript on Promise Technology's web site annoying.

The Adaptec controller is cheaper, but it is Windows only. There are apparently no Linux drivers. This is a huge drawback, since these same old data entry computers may be still running when Windows dies again, and Windows XP is no longer supported, and there are Linux versions of the data entry programs, or they run under Wine.

The Acard controller supports SuSE, Red Hat, Caldera, and Turbo Linux, it says. But remember, Froogle found only one vendor.

HighPoint says they support Linux: "Linux Red Hat 7.3 & 8.0 (Software RAID Only)". This apparently means the card does not support Linux at all, since Linux has software RAID built in.

So, that's the extent of my knowledge and experience. Can you provide further insight?"

Comments

3ware

[killmenow]

look

That's all I'm sayin...

Re:3ware

[mukund]

I work at a longtime Linux server vendor in UK. We have many many man-years of driver and performance related experience with Linux and storage hardware. I can attest to the fact that 3ware make some of the best trouble-free well-supported ATA RAID controllers for use under Linux. (Please take this as a personal opinion -- do your own research before you buy and use these controllers.)

Re:3ware

[RedDirt]

Absolutely. I have a 6000 series card (2 port) and one of their new low-profile 8506 SATA cards. Leave the consumer grade junk behind and get a well supported product. Linux works flawlessly on them and the Windows support is pretty decent also (they still make NT4 drivers available for the 6000 card).

I tried out an Adaptec 1210SA raid controller since the box claimed Linux compatability. Bull. They support a handful of distros and and even smaller number of patchlevels of kernels with their set of binary drivers. Back in the box and back to the store.

Now, granted, the 3Ware cards are more pricey. However, you get exactly what you pay for.

Re:3ware

[Anonymous Coward]

We have 3 Linux SMP servers each running a 4-disk Raid 10 (mirroring and striping) 3ware RAID array. We had started with Mylex controllers and SCSI RAID. 3ware has proven to be far less expensive, significantly faster, and more reliable (less drive failures %age wise; none of the arrays, SCSI or 3ware IDE, have ever lost data).

3ware drivers have been integrated into the Linux kernel for some time. Promise, Highpoint, etc. has binary drivers that limit your kernel options.

3ware has on-board logic to handle most of the RAID protocols independently of the main CPU, including RAID 5 and variants. The low-end guys do all this work in their driver, which is one of the reasons the are unlikely IMO to open source them.

The 3ware driver is standard in the Linux kernel. The low-end guys have binary drivers that severely limit your kernel upgrade flexibility.

My only relationship with 3ware is as a satisfied customer. If you need fast, reliable, and inexpensive storage, I'm not sure you can do better than 3ware right now.

missing option

[Tumbleweed]

Can you spell 3ware?
They do more than just mirroring, and aren't cheap, but if you wants the quality, you gots ta pay the piper.

Drivers are in the Linux kernel, and have been for some time. ATA or S-ATA versions available.

Promise TX2000 experiences

[Wintermancer]

My thoughts on the Promise FasTrack controllers:

We use 'em at work. On the Windows 2000 side, they come with decent management software and for the most part, are relatively reliable.

However, they are far from perfect. I've had several W2K servers blue screen when doing a hot-swap. Joy.

The FreeBSD drivers are bloody stable as hell. No complaints.

The Linux drivers provided by Promise are, IMHO, a POS. Pain to compile. No management software. Diagnositics are limited. As a result, I'd go with a different IDE controller card if you want it for Linux. YMMV.

Re:Promise TX2000 experiences

[flonker]

We originally used Windows NT 4.0 software mirrors, but that had too many flaws. Mirrors would sometimes break with no notice, and one mirror would end up being months out of date when something did come up. And frequently, we would have flaws with the boot process. Only one of the drives gets a real boot image, or something along those lines. I'm not quite sure what happened, someone else eventually figured it out and fixed it. But we were booting off of floppies for months on a couple servers.

Eventually, we started using Promise and Adaptec RAID controllers. Both have been wonderful. They both gave good warnings when one of the drives failed. We only had one problem in several years. One of the Promise controllers died of heat exhaustion, but that was the time the power supply fan went.

Promise FastTrak

[mnelson]

I have used several Promise FastTrak RAID controllers and have had varied results, but all in the "crappy" range. Their drivers are proprietary, so you have to stick with the pre-compiled kernel module. This means you also have to stick with a pre-compiled distro kernel so the symbols match. Promise has always been several kernel versions behind, so if there is a kernel security upgrade, you have two choices: 1. patch the kernel and break the Promise card or 2. Leave a vulnerable computer up and running. You can generally force a promise module into a non-matching kernel, but I've always been hesitant to do that.

I have switched every Promise installation to 3ware cards because of this. They are open source drivers, very current, and perform well. Their tools run as a web daemon under Linux so you can check status/reconfig on the fly. Really amazing Linux support, and a reasonable price... (and no, I'm not affiliated...:) )

Re:Promise FastTrak

[gujo-odori]

Promise cards are directly supported by the kernel, though, so you don't have to use Promise's crappy drivers.

I'm writing this on a Debian Sid system with a 2.4.20 kernel, that I installed to RAID 1 on a Promise 20265 (onboard chip). To get the support into your kernel, you need:

CONFIG_EXPERIMENTAL=y

from code maturity options, and:

CONFIG_BLK_DEV_ATARAID=y
CONFIG_BLK_DEV_ATARAID _PDC=y

from IDE chipset support/bugfixes.

If you have a Highpoint or SII, use:

CONFIG_BLK_DEV_ATARAID_HPT=y
CONFIG_BLK_DEV_ATA RAID_SII is not set

Note that the following should not be set. If they are, you will not get the ATARAID functionality, and the Promise will be seen as just an ordinary IDE controller:

CONFIG_BLK_DEV_PDC202XX_OLD
CONFIG_BLK_DEV_PDC2 02XX_NEW

A Debian install CD that supports Promise chips in RAID mode is out there, it's what I used to install this system. I don't remember where I got it, but Google can help. The kernel is 2.4.20, and it also supports Reiser and devfs.

Controller Reliability

[hopews]

The purpose of a raid card is improved reliability. Thus, you shouldn't try to cut corners on quality control to save a few bucks. After all, you're already springing for two drives.

I have had very pleasant experiences with 3ware controllers, both under linux and Win32. Currently I have a 6400 running under Suse 7.3, and three 7400s running under RedHat 8. With some hotswap drive bays, you can even unplug a drive with the system running.

They might cost a little more, but they're widely used under more grueling conditions than the more dirt cheap designs. Also, if you're simply doing raid 1, you can use one of their previous generation cards with no performance penalty, and save a bunch of bucks.

I went with HighPoint...

[Jerk City Troll]

Specifically, the RocketRaid 133 (based on the HPT372A chipset). The card runs quite well under Linux. The Linux driver from HighPoint is quite good (sadly, only partially open source) and provides a /proc interface. (Don't worry, it compiles just fine in any kernel.) Sadly, I cannot show you output from the interface because Slashdot refuses to let me post it (citing junk characters). Stupid Taco. The interface also allows you to issue commands to the controller without rebooting, but documentation is poor. The BIOS utility is also quite good.

Anyway, the device hosts two RAID-1 arrays, one with 2 80Gb Seagates (ST380021A) and the other with 2 200Gb Maxtors (6Y200P0). They appear as SCSI devices. I have tested the mirroring and I am mostly satisfied.

Basically, I simulated a failure on one disk (removing it then performing some work on the other). When I reattached the drive, the card recognized the "failure" immediately and wanted to build the array. For my first test, I let the BIOS do exactly that. Took a very long time, but the mirror was recreated successfully and there were no problems (I tested by removing the first disk and trying again--the mirror was good). The second test was letting the driver do it after the machine had booted. This was a dismal failure. The card does NOT like rebuilding the mirror once the system is running.

Performance is quite good. Even though this is not HighPoint's latest offering, I am still quite impressed. I don't have any hard benchmarks, but I can post some later if you'd like.

These two arrays are accessed by many machines in my home network over NFS and by on average 5 users logged in remotely. They serve games, web pages, and my software, movie, and music archive. These arrays take a decent amount of stress, but nothing severe.

I'll post more in this thread if I think of anything. I'll answer any questions about the card's performance if you have any.

RAID experiences

[JWSmythe]

I haven't played with RAID's other than RAID5 much, but here's my experiences. Maybe they'll help your opinion.

I've used several different external RAID5 solutions, including the Promise TX8000 and Radion arrays (and a bunch of no-name brands too). Those all worked beautifully, and survived failures without any significant problems.

I've worked with four internal hardware raid solutions. Two were the Adaptec AA-130 cards years ago, and the most recent two were Promise SuperTrak SX6000. One belonged to a friend, and one went in my machine.

My friend had several problems with his. I'll leave his story at that.

I put together a nice dual processor machine for a large photo archive site. It needed lots of space, which is why we needed the RAID5. It also needed to take up as little space as possible, so we opted for putting 6 drives in a 2u case with the SX6000. The card was incompatable with the newer chipset of the motherboard. It took two weeks of daily calls to tech support before we gave up. A week later, they released a firmware update which addressed this problem. The SX6000 doesn't handle heavy read or read/write traffic very well. When we made it an active web site, the server would crash very frequently with errors about the array. If we kept the traffic slow, it worked fine, but that what we wanted from this machine. This array solution proved to be non-functional for us, so we made the machine a backup machine, so now we have like 600Gb of storage space to back servers up to. :)

I've heard a lot of good things about 3ware, but haven't tried one myself yet.

I've been experementing with Linux's software RAID's. I've used RAID1 and RAID5, and they both work great. I've had a drive fail on two so far, but for the number of drives we use, that's acceptable. They rebuilt fine sticking in a new drive, with very little performance hit. I do like that Linux gives decent statistics in /proc/mdstat .

You seem to want multiple platforms, so I guess Linux software RAID isn't much of a solution for you.

I can simply warn against the Promise SX6000. It should have been a good card, with Promise's reputation, but I was severly disappointed.

Re:I run Linux on my 500 client network server

[pla]

Everyone knows Linux is quite a bit more stable than Windows. I really don't have any need to do this kind of redundant replication.

Assuming you didn't mean that as a troll...

HDD mirroring generally provides protection from *hardware* failure, not software glitches. If Windows suddenly decides to overwrite your porn collection, a RAID controller will faithfully do it on both drives. If you accidentally do an "rm -rf /" as root on your Linux box, again, kiss your data goodbye regardless of mirroring.