Slow read from SATA HDD in Intrepid

[Jeffery MacEachern]

I'm using the development releases of Intrepid, and when booting from kernel 2.6.27-1 or -2, my SATA read speed decreases to ~6.5-7MB/s. I have a SB600 SATA controller.

[Leann Ogasawara (leannogasawara)]

Hi Jeffery,

I just want to clarify that you did not experience this with the 2.6.26 kernel previously available for Intrepid?

[Jeffery MacEachern (jaem)]

No, I did not. I noticed immediately upon rebooting after the 2.6.27-1 update. Just FYI, I believe some Ubuntuforums.org users were experiencing similar problems with my laptop (older kernel) several months ago, but I can't find that thread now.

[Leann Ogasawara (leannogasawara)]

Thanks for the feedback. Can you attach the following when using the 2.6.27 kernel?

* cat /proc/version_signature > version.log
* dmesg > dmesg.log
* sudo lspci -vvnn > lspci-vvnn.log

Please also attach each file separately. For more information regarding the kernel team's bug policy refer to https://wiki.ubuntu.com/KernelTeamBugPolicies . Thanks again.

[Jeffery MacEachern (jaem)]

I'm very sorry for the delay; I was just starting my university term when this happened, and I needed to have a working system right away, so I temporarily switched to SuSE. I'll be re-installing Ubuntu Intrepid tonight, so I can check things out for you.

[Jeffery MacEachern (jaem)]

I booted the LiveCD of Alpha 5 to check it out, and it's still the same. I would have installed it to make absolutely sure, but GNOME was running excruciatingly slowly from the CD for some reason, and it was essentially unusable. (My CD read speeds were down to 1.5MB/s -- but that's another issue...) Anyhow, here are the attachments, and sorry for not RTM'ing first.

[Jeffery MacEachern (jaem)]

I'm having the same issue with Mandriva 2009.0 RC1, which also uses the 2.6.27 kernel. I'm not sure of the procedure if it's an upstream problem, so I'll leave it up to you, Leann. Let me know if you need more information.

[Leann Ogasawara (leannogasawara)]

Hi Jeffery,

Sorry for the delayed response here on my end. The kernel team is planning on producing a vanilla upstream kernel package for bug reporters to test if this is also an issue in the upstream kernel. I'll try to notify you via this bug report when that package is available to see if you'll be able to test and confirm.

However, it seems this was a regression from 2.6.26 to 2.6.27? If you had some spare time and were willing to do so you could try to perform a git bisect to narrow down the offending patch which cased this regression. I posted a rather long winded git bisect howto in another bug report - https://bugs.edge.launchpad.net/ubuntu/+source/linux/+bug/273266/comments/6 . Performing a git bisect is obviously not something we expect you to know how to do or even be willing to perform, so it's completely at your own discresion. Thanks.

[muzah (sylvain-lesne)]

Hi!

I have the same problem here. as I made a transfer between two HDD, the average was about 7Kb/s ! (I can post some screenshot here if necessary). I attach the dmesg log as ask before by Leann. What really append with this new release ?

Thanks for your job !

Muzah

[muzah (sylvain-lesne)]

I made an experiment :

sudo hdparm -W 0 /dev/sda

disable the write cache on my SATA device.

The transfer speed was about 7Mo/s (My bad for the first post, I wrote "7Ko/s"...) and with the Write cache disable, the transfert speed is about 45Mo/s !

Is somebody would try to do the same experiment ?

Thanks!

[johnny (johnny-localmomentum)]

disabled write cache, seems quite a bit better now.. of course.. not back to where it was.. but better

[johnny (johnny-localmomentum)]

i can't seem to find a copy of the 2.6.26 kernel that is mentioned here. can somebody link me with it? The last working kernel release i have is a 2.6.24 from hardy which seems to be missing sound drivers for my card, and all releases from that point on , either have a bug in the network interface card driver (fixed in 2.6.27), and a bug in the sata driver that causes it to not to boot (also fixed in 2.6.27)

[johnny (johnny-localmomentum)]

oops.. i meant that they were fixed in later 2.6.26 releases that are included with intrepid

[Tim Gardner (timg-tpi)]

wrong bug

[johnny (johnny-localmomentum)]

could the original poster please try the newest kernel in intrepid-proposed.

i had good luck with that

[Launchpad Janitor (janitor)]

Per a decision made by the Ubuntu Kernel Team, bugs will longer be assigned to the ubuntu-kernel-team in Launchpad as part of the bug triage process. The ubuntu-kernel-team is being unassigned from this bug report. Refer to https://wiki.ubuntu.com/KernelTeamBugPolicies for more information. Thanks.

[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Triaged a while ago but has not had any updated comments for quite some time. Please let us know if this issue remains in the current Ubuntu release, http://www.ubuntu.com/getubuntu/download . If the issue remains, click on the current status under the Status column and change the status back to "New". Thanks.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Alex Valavanis (valavanisalex)]

Intrepid Ibex reached end-of-life on 30 April 2010 so I am closing the
report. Can anyone confirm whether this issue still exists in later versions of Ubuntu?

[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]