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TQUOTE=anomie;4620105][ Just a side note: you might consider changing the thread title to something like, "Read performance issue with Ubuntu 10.04". It took me awhile to figure out what is going on here, especially given a title about verifying OS "health". ]
It would interesting to see the results of the following, from both 10.04 and 10.10 (with appropriate drive attached):
Code:
$ sudo hdparm /dev/sdc
[/QUOTE]
The results are on Post #12 of this thread. Thanks.
TQUOTE=anomie;4620105][ Just a side note: you might consider changing the thread title to something like, "Read performance issue with Ubuntu 10.04". It took me awhile to figure out what is going on here, especially given a title about verifying OS "health". ]
It would interesting to see the results of the following, from both 10.04 and 10.10 (with appropriate drive attached):
Code:
$ sudo hdparm /dev/sdc
The results are on Post #12 of this thread. Thanks.[/QUOTE]
Running your code as specified returns the following:
Be aware that these results were obtained while running Ubuntu 10.10 on the memory stick. If you need the above results while running Ubuntu 10.04 from the external hard drive, please let me know.
Thanks.
Last edited by williepabon; 03-06-2012 at 06:28 PM.
Reason: Adding code tags
Revisiting the facts (in case I've misunderstood):
You're running Ubuntu 10.04 from live (USB) media
You're running Ubuntu 10.10 from another live (USB) media
Read tests from 10.04 are substantially slower than read tests from 10.10
Read tests were conducted against the same device
Is that all correct? (Please correct if not. Getting this much straight is important to proceed logically.)
I'd like to compare and contrast the results of an hdparm(8) query from both environments. Try the command I posted from both. I am looking for something obvious, like readahead being disabled in your 10.04 environment.
Depending on the answer to that puzzle, we can try some direct device read tests to see if the results differ significantly. (By throwing the -T option into the mix, you may be adding complexity. I'm not clear what hdparm(8) does when both options are specified.)
Revisiting the facts (in case I've misunderstood):
You're running Ubuntu 10.04 from live (USB) media
You're running Ubuntu 10.10 from another live (USB) media
Read tests from 10.04 are substantially slower than read tests from 10.10
Read tests were conducted against the same device
Is that all correct? (Please correct if not. Getting this much straight is important to proceed logically.)
I'd like to compare and contrast the results of an hdparm(8) query from both environments. Try the command I posted from both. I am looking for something obvious, like readahead being disabled in your 10.04 environment.
Depending on the answer to that puzzle, we can try some direct device read tests to see if the results differ significantly. (By throwing the -T option into the mix, you may be adding complexity. I'm not clear what hdparm(8) does when both options are specified.)
anomie:
Thanks for answering. Will try to answer to he best of my knowledge.
1- You're running Ubuntu 10.04 from live (USB) media.
Not really. I did a complete install of Ubuntu 10.04 on an external hard drive that is connected to my pc via USB. I've been booting my pc from this drive for the past two years without a problem, until I installed more RAM.
2- You're running Ubuntu 10.10 from another live (USB) media
I also did a complete install of Ubuntu 10.10 on a USB memory stick (just to learn how it is done), and boot from it at times to compare features and differences, if sometime in the future I decide to upgrade my main installation (external hard drive)
3- Read tests from 10.04 are substantially slower than read tests from 10.10
Yes. This happens when I boot from the 10.04 device (hard drive). When I do the test from the 10.10 stick, everything is OK.
4- Read tests were conducted against the same device
Yes, but more than that. Booting from the 10.04, I conducted read tests to the hard drive itself, but also to devices connected to other USB ports. For that, I connected my memory stick. The readings are also slow. Apparently, the problem affects all USB ports on the pc. I think, that's what my Post #12 says.
I'm writing this post from a different machine, different location, but In a short while will send you the results of the hdparm you requested. Thanks.
Additional info:
Post #19 shows hdparm wihile being boot up with memory stick running Ubuntu 10.10.
The following is running hdparm while being boot up from my hard drive running 10.04 and having the memory stick also connected.
I'm a little puzzled by the problem you're describing. The addition of RAM (and immediate, noticeable differences in 10.04 performance) seems like a good clue. But I'd imagine you were not benchmarking I/O performance until after you noticed 10.04 "slow down" substantially.
Are you willing to temporarily remove the new RAM and see how it affects performance within your 10.04 environment? That would eliminate - or implicate - the new RAM as the problem cause.
As I mentioned, I was hoping the hdparm(8) query of the devices would provide us with a good lead. It didn't.
There are a number of additional threads we could pursue, but they are more evidence gathering rather than necessarily leading us to root cause. For instance, observe vmstat -d output while running your tests (in both 10.04 and 10.10, and compare results). And observe top(1) output to try to identify whether hdparm(8) is using an unusual amount of memory in 10.04 (again, you'd need 10.10 results to compare against).
I'm a little puzzled by the problem you're describing. The addition of RAM (and immediate, noticeable differences in 10.04 performance) seems like a good clue. But I'd imagine you were not benchmarking I/O performance until after you noticed 10.04 "slow down" substantially.
Are you willing to temporarily remove the new RAM and see how it affects performance within your 10.04 environment? That would eliminate - or implicate - the new RAM as the problem cause.
Anomie:
Other people have also suggested to remove the new RAM installed to see if the problem corrrects. I haven't done it yet because:
I did a memory test with a diagnostic program from DELL (My pc is from Dell)
My pc works fine with Windows XP, no problems with memory
My pc works fine when booting with Ubuntu 10.10 memory stick, no speed problems
My pc works fine when booting with Ubunty 11.10 memory stick, no speed problems
Regardless, I'm going to try your suggestion, this weekend (I use the machine a lot during weekdays). Will let you know what happens. Thanks
wp
Anomie:
Other people have also suggested to remove the new RAM installed to see if the problem corrrects. I haven't done it yet because:
I did a memory test with a diagnostic program from DELL (My pc is from Dell)
My pc works fine with Windows XP, no problems with memory
My pc works fine when booting with Ubuntu 10.10 memory stick, no speed problems
My pc works fine when booting with Ubunty 11.10 memory stick, no speed problems
Regardless, I'm going to try your suggestion, this weekend (I use the machine a lot during weekdays). Will let you know what happens. Thanks
wp
Anomie:
I decided to do the memory investigation today. But before doing it, to check out any possibility of hardware issues on the hard drive, I did the following: (1) purchased a new hard drive enclosure and moved my hard drive to this one, (2) purchased a new USB cable and used it to connect my hard drive/enclosure setup to a different USB port on my pc.
Then, I performed speed tests with 1 Gig, 2 Gigs and 3 Gigs of RAM with my Ubuntu 10.04 OS. Ubuntu 10.04 worked well when the pc had 1 Gig or 2 Gigs of RAM. When I increased to 3 Gigs, it slowed down to a crawl. I can't understand the relationship between an increase of 1 Gig and the effect it has in Ubuntu 10.04. This doesn't happens with Ubuntu 10.10 and 11.10. Unfortunately for me, Ubuntu 10.04 is my principal work operating system. So, I need a solution for this. Thanks for the help.
Fascinating. The good news is: you can describe the exact problem (complete with Ubuntu version and RAM amount), and you can reproduce it easily.
I'd be curious to know what's happening with memory on your 10.04 system with the extra RAM installed. (You can observe with top(1)). And I'd also be curious to know whether there are any ominous looking errors reported in /var/log/messages with the extra RAM installed.
If those offer no compelling new clues, I'd recommend posting your problem to Launchpad:
Ubuntu 10.04 is LTS, so hopefully a knowledgeable developer or tester is willing to speak to the issue you're seeing. Please post back on this thread if you get a fix -- or at least a good explanation. (That will help the next person who runs into this problem.)
Distribution: Debian Testing, Stable, Sid and Manjaro, Mageia 3, LMDE
Posts: 2,628
Rep:
Yes, a more complete picture now and it is great to have.
I know that 10.04 will run on more than 2 gigs of ram with no trouble. My wife uses it on her box with 4 and it would run on mine up through the RC version in 10.04-testing on 3 (the final wouldn't boot and still won't because plymouth became incompatible with my hardware).
top would be a good thing to run but I am not sure it will tell you anything new.
The suggestion to take this to launchpad questions is a great one. It will at least spread the bafflement around.
Then, I performed speed tests with 1 Gig, 2 Gigs and 3 Gigs of RAM with my Ubuntu 10.04 OS. Ubuntu 10.04 worked well when the pc had 1 Gig or 2 Gigs of RAM. When I increased to 3 Gigs, it slowed down to a crawl.
Try running memtest from the Ubuntu grub boot menu on each memory stick, installed one at a time. Run memtest for at least an hour or two (or longer) to see if there are any errors for each stick of memory.
This will at least verify that each memory stick is good and help to rule out a hardware problem.
Quote:
Originally Posted by williepabon
I know that RAM is not an issue because I checked it with the utility that exists on my Windows system. By the way, If I boot my system with Ubuntu 10.10 or 11.10 I don't have a USB speed problem.
Even though you checked the RAM from Windows, since you have been grappling with this for almost a week now it would not hurt to spend a few hours running memtest from your Ubuntu boot menu to test each stick of RAM.
Yes, a more complete picture now and it is great to have.
I know that 10.04 will run on more than 2 gigs of ram with no trouble. My wife uses it on her box with 4 and it would run on mine up through the RC version in 10.04-testing on 3 (the final wouldn't boot and still won't because plymouth became incompatible with my hardware).
top would be a good thing to run but I am not sure it will tell you anything new.
The suggestion to take this to launchpad questions is a great one. It will at least spread the bafflement around.
Widget:
Following your advice, I took my problem to the guys at Launchpad. It is Question #190306. If you can, read what's there and the comments from the people who answered. I implemented some of their suggestions, but none have worked so far, as I documented. Changing to a different version of the OS (as some have suggested) is like admitting that the software is at fault and that this problem does not have a solution.
Try running memtest from the Ubuntu grub boot menu on each memory stick, installed one at a time. Run memtest for at least an hour or two (or longer) to see if there are any errors for each stick of memory.
This will at least verify that each memory stick is good and help to rule out a hardware problem.
Even though you checked the RAM from Windows, since you have been grappling with this for almost a week now it would not hurt to spend a few hours running memtest from your Ubuntu boot menu to test each stick of RAM.
Tommcd:
On my post #25 I describe the tests that I made. I have on my pc 2 512 Meg chips and 2 1 Gig chips for a total of 3 Gigs. As I explained above, when I put 1 Gig or 2 Gigs (using the 2 1Gig chips) I have no speed problems. Everything works OK. It is when I go up to 3 Gigs that the OS slows down. Thanks for your comments.
Last edited by williepabon; 03-12-2012 at 08:59 PM.
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