SATA vs ATA? 111
An anonymous reader asks: "I have a client that needs a server with quite a bit of storage, reasonable level of reliability and redundancy and all for as cheap as possible. In other words they need a server with a RAID array using a number or large hard drives. Since SCSI is still more expensive than ATA (or SATA), I'm looking to using either an ATA or a SATA RAID controller from Promise Technologies. While I had initially was planning on using SATA drives, I have read some material recently to make me rethink that decision and stick with ATA drives.
What kind of experiences (good and bad) have people had with SATA drives as compared to ATA drives, especially in a server type environment?"
Don't use Promise, for one thing (Score:5, Insightful)
Re:Don't use Promise, for one thing (Score:4, Informative)
One thing about SATA is that it's easy to remotely mount the drives. You can easily put them outside the machine (in a rack or whatever) for enhanced cooling. They're kinda like really fast firewire drives.
Re:Don't use Promise, for one thing (Score:1)
Re:Don't use Promise, for one thing (Score:1)
Why is RHEL 3.0 "junk"??? (Score:1)
I've played with many a distribution over the last ten years, and when it came time to choose a web and file platform at work, RHEL was the best value in my opinion. I pay for one update subscription and feed all my other RHEL installations from that. I'm sincerely curious as to how the product has disappointed you. I find it to be rock solid and well tuned. And, no, I have no affiliation with RedHat other than my single subscription, for which we paid full freight.
Re:Why is RHEL 3.0 "junk"??? (Score:2)
Second your thoughts about RHEL being a decent system, though. Would our systems be running it if I were in charge of the budget? Probably not. Is there anything wrong with RHEL? Nah.
Re:Why is RHEL 3.0 "junk"??? (Score:1)
Yeah - - my thoughts, too. I just get tired of hearing people labeling the work of talented developers as "junk." Especially when the people being criticized have made many contributions to OSS, and the ones hurling the insults just have their panties in a wad because they couldn't get their ripped-off MP3s to play, or their porn viewer did not have the right codecs installed by default. I suspect most people who so flippantly disparage the work of others have never written a piece of software for public co
Re:Don't use Promise, for one thing (Score:4, Insightful)
Their only major drawback I saw last time I looked at their hardware was that Linux drivers at the time tended to be binary and proprietary to specific versions (works on redhat but not Suse, etc.), which may or may not matter depending upon the OS you're choosing to run.
I don't work for them, and I don't even use their equipment in any of my stuff (a buddy of mine runs an SX4000 card, though, so I have seen them in action), but I do get a bit peeved when someone dismisses a company's higher-end solutions because of (admittedly) bad experience with their low-end kit.
Re:Don't use Promise, for one thing (Score:5, Informative)
Bad experience with Promise. XP problem with RAID. (Score:2)
We've had trouble getting tech support for Promise equipment recently.
This is uncertain, but it seems that there is some bug in Windows XP which causes RAID cards that don't have their own CPUs to malfunction. According to a HighPoint technical support rep, the RAID adapter card does not get enough CPU time, and writing to the drives times out, breaking the RAID array. This fits with our experience.
Re:Don't use Promise, for one thing (Score:2)
Promise has released the source to their SATA card drivers, but it's written for the 2.4 kernels and at least the build process would need to be updated for them to compile cleanly in 2.6. In any case, the only reason to do so would be to get the PATA port working, and
Re:Don't use Promise, for one thing (Score:2)
the thing just is that they don't come cheap.
cheapo cards are just an easy way to add more (s/p)ata slots.
Re:Don't use Promise, for one thing (Score:2)
3ware has great support and superior benchmarks to the Promise, et al. equivalents.
Do your own homework/research, but 3ware appears to be the clear performance leader.
Re:Don't use Promise, for one thing (Score:1)
Click on the Promise link you insensitive clod, ALL FastTrak SX4xxx series controllers are HARDWARE RAIDs
http://techreport.com/reviews/2002q4/ideraid/inde
Promise SX4xxx is the best in the low budget area (beating Adaptec and 3ware).
Don't even think about.... (Score:1)
It's a tradeoff. (Score:1)
Connectors are poor on SATA (Score:3, Interesting)
Re:Connectors are poor on SATA (Score:3, Interesting)
Re:Connectors are poor on SATA (Score:2)
3ware (Score:2)
www.3ware.com [3ware.com]
does raid in hardware unlike most (all?) promise, yadda yadda, software raid faster than battery-backed hardware, yadda yadda yadda, do you really need hot swap? if not, software raid, yadda yadda
Comment removed (Score:4, Interesting)
Re:no-brainer (Score:2)
A
Re:no-brainer (Score:1)
I have a few 486 motherboards with PCI slots and 72-pin memory slots I can sell you. Some even sport 5x86 cpu chips.
Re:no-brainer (Score:1)
You don't buy 5-year warranty drives because they won't fail (they will). You buy them because WD is REALLY good about sending advance replacements. Seagate is less good (they want the bad drive in their hands first).
Get yourself 4 or more of these drives and set up a RAID5 array with a hot spare. If a drive fails, you get a new one from WD, swap it for the old one, send the old one back in the same mailer box, and continue, with no downtime - for five
Re:no-brainer (Score:2)
Or, if it's your fancy, no PATA drive matches the Raptor 10k RPM SATA drive. Imagine two of those striped... yummy...
Re:no-brainer (Score:1)
Don't use Promise... (Score:2)
Re:Don't use Promise... (Score:3, Informative)
Re:Don't use Promise... (Score:2)
Write performance:
local writes are 27 MB/sec (~5MB files, unloaded CPU)
If both RAIDs are written together, performance cut in half
(not what we were hoping...)
local writes to local disk (/scr0) are 40 MB/sec
NFS writes to RAID are 200 times slower (1 minute per file)
NFS writes to single disk are
Re:Don't use Promise... (Score:3, Informative)
I haven't experienced any issues like that, and can confirm that the hot-swap and hot-spare capabilities work as expected on the 9500-12. I have not performed any benchmarks
Re: (Score:1)
Re:Don't use Promise... (Score:2)
Buy a RAID (Score:2)
Re:Buy a RAID (Score:5, Informative)
Apple's 3.5TB system costs $10,999 US. If you were to build a system that comprised 9 Hitachi 7200RPM 400GB drives, you would acheive 100GB more storage space for 3,600$ plus the cost of the server it was hosted in. Throw in 750$ for a high-end RAID card and 1000$ for a server to enclose and handle it, and you're still priced at under HALF the price of Apple's solution.
So, in conclusion, Apple's solution is many things, and is certainly VERY sexy and attractive. But inexpensive compared to a self-built solution it is NOT.
Re:Buy a RAID (Score:1)
Re:Buy a RAID (Score:2, Flamebait)
Plus the power supplies (dual redundant) and cooling systems (dual redundant) and controllers (dual redundant) and the case to house it all!
That's an awful lot of stuff to just hand-wave away. Not to mention the time and labor required to build and support the fucking thing.
But inexpensive compared to a self-built solution it is
Re:Buy a RAID (Score:2)
I had budgeted 1000$ for the rest of the server. A fast processor isn't required since we have all-hardware controllers. As long as the CPU isn't saturated under heavy load, all is good.
You think you can't fit redundant power, cooling, and controllers into that 1000$? Fine, add another 1000$. 2000$ even. That's 3000$ total for the server plus the 3600$ for the drives. That's 6600$ in total, still a good 5500$ cheaper than Apple's solution.
Re:Buy a RAID (Score:2)
The dollar sign goes in front of the figure, not behind it. Basic literacy isn't too much to ask, I hope?
I happen to like writing currency how it's read. Is that too much of a problem for you? Does your brain shut down when you see it written that way, and you can no longer understand? Didn't think so.
Heh. That's good. That's funny. Run along and play now, you fucking amateur. Leave the discussion of business-class RAID systems to the
Re:Buy a RAID (Score:2)
Except Apple doesn't provide you with drive carriers for all the bays and won't sell them to you without a hard drive. Basically, they want to sell you the drives for their price and don't want to support the Xserve RAID with drives from who-knows-where.
Re:Buy a RAID (Score:2)
Ah well, the option remains, it seems, to purchase a 14-drive machine and bump it up to a 5.6TB system by purchasing your own drives. That is, if the drives don't have custom firmware, as the earlier troll suggested.
Re:Buy a RAID (Score:1, Flamebait)
And I don't recall telling you that I care. You're free to whine about it, of course, but I'm not quite sure what point that serves.
Firmware. If you require more explanation than this, then you're so far out of your depth that I can't even see you from here.
Try not to be quite so patronizing, it doesn't fit you well. I'm going to combine this with your next comment and ask you to provide proof. Your "Because I said so"
Re:Buy a RAID (Score:1, Troll)
"Proof?" You're funny. You're like a joke. You're funny.
This isn't a school. I'm not your teacher. If you're ignorant, it's your responsibility to do something about it.
Off you go, little boy. Go play.
Re:Buy a RAID (Score:1)
Re:Buy a RAID (Score:2)
Re:Buy a RAID (Score:2, Informative)
Re:Buy a RAID (Score:2)
Re:Buy a RAID (Score:2)
It does not have either redundant or hot-swap fans. They're not available at any price. When a fan fails, you have to shut the RAID down to replace it... assuming you catch it in time. It doesn't appear to come with any sort of monitoring system that informs you of the health of things like the controller, the power supply, and the fans.
Finally, it doe
Re:Buy a RAID (Score:2)
Frankly, I don't see the failure of chips to be a big issue. Moving parts, sure. And if you're that concerned, you shouldn't count on one storage device anyway. There's always *some* one thing that can fail inside one box.
It doesn't appear to come with any sort of monitoring system that informs you of the health of things like the controller, the po
Re:Buy a RAID (Score:2)
Spoken as only somebody who's never had a RAID controller fail on them can.
And if you're that concerned, you shouldn't count on one storage device anyway. There's always *some* one thing that can fail inside one box.
Well... actually no. In a well-built RAID--not just Apple's, but anybody's--there is no single point of failure. Two totally separate and redundant power supplies. Two totally separate and redundant controllers. Two totally separa
It's all in the name (Score:4, Informative)
I was using SuSE 8.2 and they had no drivers but they "promised" that they would be out by the end of the month. Of course I could compile them myself but since that required installing the OS which was impossible without the drivers that required finding another machine and dealing with other problems.
After about 3 months of "promise" after "promise" (this month for sure) they told me it the drivers would be out "in a couple months". The longer I waited the longer away the drivers were scheduled.
It wasn't like I had grabbed 8.2 when it was released either. Promise's Linux "support" was way behind and they basically told me that Linux is their poor stepchild that gets leftover resources when Windows stuff is done.
I contacted my vendor and had them swap the Promise card for a 3-ware. I tossed in the disk and loaded SuSE without any need for downloading or compiling drivers. I'm running RAID-5 on 4 120GB drives. I had a drive fail a couple months back but just hot-swapped/rebuilt it with no problem. The machine was up for about a year before I had to shut it down to replace a failed tape drive but I've had no trouble with the 3-ware.
Re:It's all in the name (Score:3, Interesting)
Why doesn't Promise abstract their cross-platform code from the Linux and Windows device driver "glue" code? Then they could just port the Linux and Windows specific code once and all their device drivers' platform-independent code should "just work". (but keep your fingers crossed anyways)
I know Linus does not like cross-platform wrapper crap code in his kernel, but there is nothing preventing Promise from doing this outside the Linus tree or wrapping the Linux device driver API around the Windows devi
Re: (Score:1)
Look at Apple's Xserve RAID (Score:3, Insightful)
I would avoid the other controller cards you mentioned for the reasons the other posters mentioned. The Xserve RAID is all the benifits of a good scsi backplane (RAID, monitoring, etc) for a fraction of the cost.
Re:Look at Apple's Xserve RAID (Score:1)
Re:Look at Apple's Xserve RAID (Score:1)
RAIDCore SATA (Score:1)
-Bill
These things look pretty (Score:3, Informative)
StoreCase Technologies [storcase.com]
RAID boxen with ATA on the inside, SCSI and/or FC on the outside. Seemingly incredable warrenties of as long as 7 years.
Dangers of using ATA or SATA for Raid (Score:5, Interesting)
Losing data on an ata raid array happened to a friend of mine and I wouldn't advise using something other than SCSI without understanding the ramifications.
Best regards,
Doc
I made a new years resolution to give up sigs...so far so good!
Re:Dangers of using ATA or SATA for Raid (Score:4, Informative)
Of course, if you are using a hardware RAID controller, you'll have to figure out how to tell it to disable the write-behind cache on the drives under its control. Perhaps it will be smart enough to figure it out if you use the hdparm command on the logical device it presents to the operating system, but I'd certainly want to read the manual and find out.
I know from experience that Windows 2000 automatically disables write-behind caching on drives in software RAID arrays (and dumps some Informational messages in the system log to let you know what's going on).
Re:Dangers of using ATA or SATA for Raid (Score:2, Interesting)
Furthermore, if I am using a hardware raid how do I use hdparm? And finally, ATA drives have write-back ON by default, SCSI d
Re:Dangers of using ATA or SATA for Raid (Score:2)
Infact, most hdparm functions don't work on scsi.. Even tho features like turning off the disk motor were supported on scsi first
Re:Dangers of using ATA or SATA for Raid (Score:4, Insightful)
First off I'd assume if your data is so important you're going to have UPS and generators. If you don't have a generator, and the power fails, great, you've got 24 hours to purchase one. A 1500W generator costs about 450$ US, and should be more than powerfull enough to run your server, AND network connectivity. You'll not only keep your server happy during a power failure, you'll be able to keep using the server.
Anyhow, this post started out about the battery backup. What you stated as a major problem isn't one, since serious ATA RAID solutions have battery backup.
Re:Dangers of using ATA or SATA for Raid (Score:2)
From the standpoint of the OS, the data has been written to the HD but it is actually "lost".
Of course if you were building a real server (i.e. not for hosting large amounts of mp3s, porn, movies, etc.) you'd probably disable the cache on the drives and let the RAID controller do its job (assuming you bought a RAID controller with cache).
But a better solution, for a storage only server, would
Re:Dangers of using ATA or SATA for Raid (Score:2)
The drives also appear to be ATA.
Re:Dangers of using ATA or SATA for Raid (Score:2)
From the standpoint of the OS, the data has been written to the HD but it is actually "lost".
If you've got any kind of error checking at all that shouldn't even be an issue. If the OS thinks the data was written to a drive then it should be recovered during rebuild, assuming it was only one drive that went. That's exactly the sort of failure that every RAID level other than 0 is designed to
Re:Dangers of using ATA or SATA for Raid (Score:2)
Re:Dangers of using ATA or SATA for Raid (Score:2)
I strongly suggest you educate yourself on how RAID works. Here [arstechnica.com] is a good place to start.
Re:Dangers of using ATA or SATA for Raid (Score:2)
You obviously weren't in the middle of the East Coast after Isabel hit last fall and wiped out power throughout our entire area for over a week. I don't remember the numbers, but in our area, after something like 5 days there was still only a 60% restored rate for the area. For days travel in some areas was impossible, due to trees on the roads, etc.
I would have been willing to
Re: (Score:1)
Re:Dangers of using ATA or SATA for Raid (Score:2)
Actually, the closest wasn't in front of my house (but three fell into my yard from other yards), but there were something like 10 (I'm not exaggerating!) trees down across the road between me and the closest main road (as in not a neighborhood road).
First, you could go around the debris
Like I said in my first post, You obviously weren't in the middle of the East Coast after Isabel hit last fall.
Re: (Score:1)
Re:Dangers of using ATA or SATA for Raid (Score:2)
Re: (Score:1)
Re:Dangers of using ATA or SATA for Raid (Score:2)
Besides, 5 days of down time is nothing compared to
Re:Dangers of using ATA or SATA for Raid (Score:2)
It has special set-aside space on a number of drives that it designates as the "cache vault". Then, it has its own special UPS connected to the box that holds the RAID controllers and the first 10 drives of the system. When the main power fails, the controllers flush the write cache to this "cache vault" location, and then tell the UPS that its ok to "shut down now". Whe
Reliability when cache writes lost- journalling (Score:1)
RAID cards with CPUs could, theoretically, recover (Score:2)
This is speculation, but it seems to have some validity. In the case of a RAID adapter that has an on-board CPU, the card might be able to recover from a power failure. The capacitors on the RAID adapter should hold enough energy for a few milliseconds of operation. During that time the adapter could write to non-volatile memory on the adapter enough information to know what data is lost and how it can be recovered.
Again, this is speculation, but RAID adapter cards that do not have on-board CPUs depend
(non) Dangers of using ATA or SATA for Raid (Score:3, Interesting)
I don't buy this argument one bit.
I agree with you that write-back can break journalling FS guarantees.
However, I don't know of any consumer drive vendor that guarantees that their write-back algorithms are in-order. This means that write-back can trash *any* filesystem, and whet
Re:Dangers of using ATA or SATA for Raid (Score:3, Insightful)
And, yeah! Guess what? Buy their software to fix it! Move along
I wouldn't advise using something other than SCSI without understanding the ramifications.
Uh, would you advise to use anything without understanding the ramifications?
Client/Server (Score:5, Funny)
I have a client that needs a server.
On a related note, I was having dinner at a restaurant and my waiter asked me for a recommendation for a good email program. So I guess it turns outs that I have a server that needs a client.
Non-Performance Related Problems (Score:2, Interesting)
Re:Non-Performance Related Problems (Score:2)
3ware escalades are quite good. (Score:2)
http://www.3ware.com/products/serial_ata.asp
Don't Confuse (Score:4, Insightful)
(P)ATA and SATA are connection technologies.
They have their individual benefits and drawbacks
(cost, reliability, speed)
The real factors to consider are the details of the drives themselves - vibration dampening, bearing and motor quality, MTBF.
It used to be rather simple to guess what quality of drive you were buying. If it was 146GB or less (73GB, 36GB), and rotational speed was 10K or 15K, it was either SCSI or FC, and an "enterprise" class drive, rated in Mean Time Between Failure.
Good drive, high quality, expect it to last several years, spinning 24 hours a day, sustaining high read and write activity during production and backup hours.
If the drive was larger (200GB+) and slower (7200 RPM), typically an ATA drive, maybe low end SCSI.
Then it was, at best, a workstation class drive, rated in "Contact Start Stops", meaning how many spin-ups and shutdowns the drive should survive. Not meant to run 24 hours a day, and run under heavy load except for short periods.
The lines are beginning to blur with 300 - 500 GB drives with FC drive attachment. Those drives are meant for archiving and reference data. Not production databases and such.
In my personal experience, the 3Ware products are worth the premium.
Pick your attachment technology as appropriate.
Best of Luck,
Patrick (slineyp at hotmail dot com)
My experience with RAID cards (Score:2, Interesting)
Performance: Naked drive with linux raid #1 Megaraid/3ware - both slower
I don't know why but how come linux with naked drives using software raid *always* comes in the top with performance. May be you guys can tell me.
Re:My experience with RAID cards (Score:2, Insightful)
The hardware raid controllers have limited clock speeds and less RAM than your computer, so they're slower.
Experience... (Score:4, Interesting)
SATA is not that much faster in practice than PATA, because the kinds of load that you put a drive under in a production environment are not like the speed/load tests used to generate benchmark numbers.
You asked for opinions, and mine is that PATA (ATA-133) is more than fast enough, and the cost of SATA and the quirks that have yet to be ironed out are not worth it. It's the latest shiny object, and shiny objects are not always the most useful.
I base my experience on the Western Digital SATA (mostly 36 gig) drives and the Western Digital 40 and 80 gig JB drives connected to multiple brands of motherboards and add-on controller cards.
All you need (Score:3, Funny)
So what you need is this [gmail.com].
Mmmm new tech still developing or old reliable (Score:2)
You gain technology that is now so well known and tested that you can just count on it to work.
Sata on the other hand still isn't finalized in its spec. New one is coming out wich adds some new features. (or has recently).
So for me I look at the following things. (note this mostly applies to webserver or servers in support of webservers)
RaidCore (Score:3, Interesting)
Here are some of the highlights from their page [raidcore.net]:
Online capacity expansion and online array level migration
Split mirroring, array hiding, controller spanning, distributed sparing
All RAID levels including RAID5/50, RAID1n/10n
Serial ATA-based
Choice of 4 or 8 channels and 2 functionality levels
64-bit, 133 MHz PCI-X controller in a low-profile, 2U module
And the HIGH-END board can be had for under $350!
Re:RaidCore (Score:1)
I would have to doubt what benefits this gives you over software raid, as it appears to use your CPU anyway. I think you are far mo
Re:RaidCore (Score:2)
The speed they achieve is astounding, and the setup can ALL be done with NO os loaded.
This does not SEEM like softRaid to me, but i am NOT an expert on these things. Simply a VERY satisfied customer.
Re:RaidCore (Score:2)
A: The RAID processing and caching is done on the host motherboard. Performance is so high because of today's high CPU speeds and patented RAIDCore RAID algorithms.
Re:RaidCore (Score:2)
Also they write that their algorithm is patented, and about linux drives
I still would recommend 3ware, fast, stable, and proven linux drives (since at least kernel 2.2, and fully open souce)
3ware + ATA hotswap trays (Score:2, Informative)
If you're going for more than just 2 or 3 drives and want to go SATA you should go with one of
LSI, Promise, 3Ware (Score:1)
LSI are great and not too expensive. They offer hardware raid support (not like promise, highpoint, etc.) for a good price and excellent linux support. They same driver and software that is used in their SCSI line of MEGARAID controllers is used in their series of SATA controllers. This is my recommendation.
The promise controller has HORRIBLE linux support. Having emailed with promise many times about the SX6000 I can tell you to avoid it. If it is too late, you need to run it as a