[opensuse] Considering a move from SCSI to SATA
Hello We have always used SCSI disks in our data collection systems. The data collection can be quite a bit at a time. 1 MB per second is not unusual. And this is sustained for, perhaps, hours at a time. We originally chose SCSI when the option was IDE. It was a no-brainer. Over time, SATA disks have made great progress. For example, this disk from Western Digital: http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h... My question is, does anyone have any experience with these disks when writing sustained amounts of data? I am guessing there is some interaction between the disk, the controller, and the Linux device driver in terms of features available. Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer wrote:
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
I am guessing there is some interaction between the disk, the controller, and the Linux device driver in terms of features available.
Roger, I use a few SATA servers but I don't have any experience with that disk and neither is my application critical over write rates. You might want to explore the information on this wiki: https://ata.wiki.kernel.org/index.php/Main_Page You might also get good advice if you post your question on the linux-ide mailing list. Cheers, Dave PS I avoid WD disks now because of the issues you will discover if you google 'TLER' -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Thu, 2011-07-14 at 09:58 +0100, Dave Howorth wrote:
PS I avoid WD disks now because of the issues you will discover if you google 'TLER'
If TLER is disabled, would the disk then act like any other disk? The article I read said: "In a non-RAID environment, such features are unhelpful, and manufacturers do not recommend their use." My use is non-RAID. Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On 14/07/11 10:58, Dave Howorth wrote:
Roger Oberholtzer wrote:
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
I am guessing there is some interaction between the disk, the controller, and the Linux device driver in terms of features available. Roger,
I use a few SATA servers but I don't have any experience with that disk and neither is my application critical over write rates.
You might want to explore the information on this wiki: https://ata.wiki.kernel.org/index.php/Main_Page
You might also get good advice if you post your question on the linux-ide mailing list.
Cheers, Dave
PS I avoid WD disks now because of the issues you will discover if you google 'TLER' Dave, you got me a little worried with the 'TLER' and WD20EARS Hard drives I use on two 3Ware 9650-2P cards with RAID 1.
From this site: http://kb.lsi.com/KnowledgebaseArticle15639.aspx I gather the WD-HD's are TLER deactivated. I used older WD3200KS disks on a 3Ware 4Port as RAID 5 for 5 years, and always wondered why I had to send half of the disks (from 2 such systems) back to WD (had 5 year guarantee :-) ). They were degraded by the 3Ware controllers after about 2-3 years. Could this be due to this TLER? Then I replaced all with 500 GB Samsung HD's, which seem to be stable. :-) Al -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On 15/07/11 05:19, LLLActive@GMX.Net wrote:
On 14/07/11 10:58, Dave Howorth wrote:
Roger Oberholtzer wrote:
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
I am guessing there is some interaction between the disk, the controller, and the Linux device driver in terms of features available. Roger,
I use a few SATA servers but I don't have any experience with that disk and neither is my application critical over write rates.
You might want to explore the information on this wiki: https://ata.wiki.kernel.org/index.php/Main_Page
You might also get good advice if you post your question on the linux-ide mailing list.
Cheers, Dave
PS I avoid WD disks now because of the issues you will discover if you google 'TLER' Dave, you got me a little worried with the 'TLER' and WD20EARS Hard drives I use on two 3Ware 9650-2P cards with RAID 1.
From this site: http://kb.lsi.com/KnowledgebaseArticle15639.aspx Pardon, it was this wiki page: http://en.wikipedia.org/wiki/Time-Limited_Error_Recovery#Raid_Controllers
I gather the WD-HD's are TLER deactivated.
I used older WD3200KS disks on a 3Ware 4Port as RAID 5 for 5 years, and always wondered why I had to send half of the disks (from 2 such systems) back to WD (had 5 year guarantee :-) ). They were degraded by the 3Ware controllers after about 2-3 years. Could this be due to this TLER? Then I replaced all with 500 GB Samsung HD's, which seem to be stable.
:-) Al
:-) Al -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer wrote:
Hello
We have always used SCSI disks in our data collection systems. The data collection can be quite a bit at a time. 1 MB per second is not unusual. And this is sustained for, perhaps, hours at a time.
We originally chose SCSI when the option was IDE. It was a no-brainer.
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
When compared to the disk transfer rates, 1Mb/sec does not seem to be a lot of data? I ran some tests a few months ago on larger (1-2-3Tb) drives - on a 3Tb WD Caviar Green, the read/write varies from 120Mb/sec to 58Mb/sec. I did not look at io rates or disk beahviour over longer sustained periods of time though. -- Per Jessen, Zürich (15.8°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Thu, 2011-07-14 at 11:18 +0200, Per Jessen wrote:
When compared to the disk transfer rates, 1Mb/sec does not seem to be a lot of data?
Perhaps not. But back when we were deciding on SCSI vs PATA/IDE, it was. Remember that older IDE involved the CPU to a much larger extent than SCSI does. That was one reason SCSI was preferred. SATA seems better in this respect (CPU usage).
I ran some tests a few months ago on larger (1-2-3Tb) drives - on a 3Tb WD Caviar Green, the read/write varies from 120Mb/sec to 58Mb/sec. I did not look at io rates or disk beahviour over longer sustained periods of time though.
Sustained use is a big part of the question. Also, the data is to different files, and thus different locations on the disk. I suspect that I am being overly cautious. I just hope the SATA drivers for openSUSE 11.2 (2.6.31.14-51-desktop) are up to the task. Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer wrote:
Sustained use is a big part of the question. Also, the data is to different files, and thus different locations on the disk.
I suspect that I am being overly cautious. I just hope the SATA drivers for openSUSE 11.2 (2.6.31.14-51-desktop) are up to the task.
You need to be cautious about the disks you choose and especially what controller you are using. There has been a lot of bug fixing in libata since 2.6.31. The wiki may list issues, otherwise search the kernel change log or generally google the model numbers. It's possible to update the kernel if necessary, of course. You might find it best to just buy a disk and try it to see what issues emerge, if any. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Roger Oberholtzer wrote:
On Thu, 2011-07-14 at 11:18 +0200, Per Jessen wrote:
When compared to the disk transfer rates, 1Mb/sec does not seem to be a lot of data?
Perhaps not. But back when we were deciding on SCSI vs PATA/IDE, it was.
Must have been a long time ago :-) I also tested some older 40Gb drives - 6-7year old Hitachi Deskstars - they did 40-50Mb/sec.
Remember that older IDE involved the CPU to a much larger extent than SCSI does.
I have usually thought that SCSI had better IO rates under heavy concurrent access (due to it's native command queueing), the CPU usage was never a concern for me.
That was one reason SCSI was preferred. SATA seems better in this respect (CPU usage).
A lot of SATA drives support NCQ nowadays. I would just test it if I were you - fake your workload with a simple shell-script, then run it on different disks and see what you get. (though it will still be difficult to profile hardware behaviour over longer periods of time). -- Per Jessen, Zürich (17.0°C) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
El 14/07/11 05:34, Roger Oberholtzer escribió:
On Thu, 2011-07-14 at 11:18 +0200, Per Jessen wrote:
When compared to the disk transfer rates, 1Mb/sec does not seem to be a lot of data?
Perhaps not. But back when we were deciding on SCSI vs PATA/IDE, it was. Remember that older IDE involved the CPU to a much larger extent than SCSI does. That was one reason SCSI was preferred. SATA seems better in this respect (CPU usage).
I ran some tests a few months ago on larger (1-2-3Tb) drives - on a 3Tb WD Caviar Green, the read/write varies from 120Mb/sec to 58Mb/sec. I did not look at io rates or disk beahviour over longer sustained periods of time though.
Sustained use is a big part of the question. Also, the data is to different files, and thus different locations on the disk.
http://www.amazon.com/Intel-SATA-2-5-Inch-Solid-State-Drive/dp/B004T0DNP6/ref=sr_1_2?ie=UTF8&qid=1310712617&sr=8-2 a decent bet, though $1K each. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Hello, On Thu, 14 Jul 2011, Roger Oberholtzer wrote:
We originally chose SCSI when the option was IDE. It was a no-brainer.
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
Well, basically all disks have been the same as a medium for some years now (PATA/SATA/SCSI). PATA was dropped at 500G (or less). What is different are: disk diameters (3.5" (IDE,SATA,SCSI), 2.5" IDE/SATA laptop/fast SCSI, and smaller (special uses)), rotating speeds (5.4-7.2k min^-1 with 3.5" IDE/SATA, 5.4k and slower with laptop disks, 7.2k/10k/15k for Servers). And of course: what the disks are built for (laptop for frequent start/stop, server for 24/7, run-o-the-mill: something like 8/7), i.e. mechanics/robustness (motor, spindle, bearing, temperatures). And the firmwares, e.g. SCSI Command-Set Features, how the firmware reacts to a unreadable sector ("Server": fast timeout, report "Bad Sector" in a second (+-), "Consumer": retry read for up to e.g. 25 seconds). The explicit 24/7 "RAID version" SATA disks with 5 years guarantee out there, that are almost twice as expensive as normal SATA drives, they're basically the same drives as what you can get with SCSI/SAS, with only slightly different connectors and electronics than their SCSI/SAS twins. Their prices are accordingly high. That SATA Velociraptor (WD6000BLHX) is *probably* the same disk as the SAS S25 600GB (WD6000BKHG), just with a different interface, but same hard- and firmware. Basically, the decision is "Laptop" (c.f. above), "Consumer" (SATA, 3.5", <= 7.2k) or "Server" (>= SATA/SAS/SCSI, 2.5" or 3.5", >= 7.2k, explicit 24/7, other firmware (resp. error handling behaviour)) ... Well, that's about what I know ;)
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
That rate of 1 MB/s (ah, mislaid the quote) should be no problem with _any_ magnetic disk available, even laptop drives. I'd have a look at the I/O scheduler though (and probably fine-grain that with cgroups / ionice, so that your "writing process" has high priority). HTH, -dnh -- I didn't know it was impossible when I did it. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Thu, Jul 14, 2011 at 4:27 AM, Roger Oberholtzer
Hello
We have always used SCSI disks in our data collection systems. The data collection can be quite a bit at a time. 1 MB per second is not unusual. And this is sustained for, perhaps, hours at a time.
We originally chose SCSI when the option was IDE. It was a no-brainer.
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
My question is, does anyone have any experience with these disks when writing sustained amounts of data?
I am guessing there is some interaction between the disk, the controller, and the Linux device driver in terms of features available.
Yours sincerely,
Roger Oberholtzer
OPQ Systems / Ramböll RST
Roger, I do a lot of sustained disk i/o for various reasons. The biggest issue with your workload is that it can be too SLOW for some disk drives. I know you did not propose a WD Green drive, but they are the worst about seeing a small period of no activity and powering off, then when the data starts coming again, they are too slow to spin up and cause the kernel to kick a i/o error back to userspace. That happens in both Linux and Windows, so it is definitely a drive issue, not a core OS issue. There is a Linux package (storage.fixup) that attempts to prevent that from happening by making appropriate reconfiguration calls to hdparm. Since you said it was for an older version of openSUSE, you should get the latest storage.fixup package and make sure you understand it and review the problem drives is lists. I'm pretty sure it would be easy to backport. (It is part of the normal distro release, but I don't think new updates get backported to the older openSUSE releases.) Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
El 14/07/11 04:27, Roger Oberholtzer escribió:
Hello
We have always used SCSI disks in our data collection systems. The data collection can be quite a bit at a time. 1 MB per second is not unusual. And this is sustained for, perhaps, hours at a time.
We originally chose SCSI when the option was IDE. It was a no-brainer.
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
I suggest you pick up Intel SSD drives if you have budget for them, not particulary cheap but _really_ fast. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
On Fri, 2011-07-15 at 02:38 -0400, Cristian Rodríguez wrote:
El 14/07/11 04:27, Roger Oberholtzer escribió:
Hello
We have always used SCSI disks in our data collection systems. The data collection can be quite a bit at a time. 1 MB per second is not unusual. And this is sustained for, perhaps, hours at a time.
We originally chose SCSI when the option was IDE. It was a no-brainer.
Over time, SATA disks have made great progress. For example, this disk from Western Digital:
http://www.tomshardware.co.uk/wd6000hlhx-velociraptor-600gb,review-31853-3.h...
I suggest you pick up Intel SSD drives if you have budget for them, not particulary cheap but _really_ fast.
We are considering SSD storage in the near future. We plan to see what the next release from intel will feature. I have heard rumors that the disks themselves will handle garbage collection. And that they will be faster-cheaper-better-all-the-rest. Until then, it will be SATA. We are conservative in making changes because these are in measurement systems that are sent to customers all over the world. We need to know things work. Yours sincerely, Roger Oberholtzer OPQ Systems / Ramböll RST Office: Int +46 10-615 60 20 Mobile: Int +46 70-815 1696 roger.oberholtzer@ramboll.se ________________________________________ Ramböll Sverige AB Krukmakargatan 21 P.O. Box 17009 SE-104 62 Stockholm, Sweden www.rambollrst.se -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (7)
-
Cristian Rodríguez -
Dave Howorth -
David Haller -
Greg Freemyer -
LLLActive＠GMX.Net -
Per Jessen -
Roger Oberholtzer