Bug 102194
| Summary: | Disk READ performance worse compared with 2.4.20-18.9smp | ||||||||
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| Product: | Red Hat Enterprise Linux 3 | Reporter: | Winfrid Tschiedel <Winfrid.Tschiedel> | ||||||
| Component: | kernel | Assignee: | Doug Ledford <dledford> | ||||||
| Status: | CLOSED ERRATA | QA Contact: | Brian Brock <bbrock> | ||||||
| Severity: | medium | Docs Contact: | |||||||
| Priority: | medium | ||||||||
| Version: | 3.0 | CC: | guenther.seybold, petrides | ||||||
| Target Milestone: | --- | ||||||||
| Target Release: | --- | ||||||||
| Hardware: | i686 | ||||||||
| OS: | Linux | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||
| Doc Text: | Story Points: | --- | |||||||
| Clone Of: | Environment: | ||||||||
| Last Closed: | 2004-05-12 01:07:33 UTC | Type: | --- | ||||||
| Regression: | --- | Mount Type: | --- | ||||||
| Documentation: | --- | CRM: | |||||||
| Verified Versions: | Category: | --- | |||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||
| Embargoed: | |||||||||
| Bug Depends On: | |||||||||
| Bug Blocks: | 103278 | ||||||||
| Attachments: |
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Description
Winfrid Tschiedel
2003-08-12 13:51:40 UTC
What version of RHEL beta kernel were you testing against? Please also test with the latest kernels available in sushi. Hello Matt, Sorry being so late with the answer, I can add now some more details the IO performance is independant from the SCSI controller. I tried AIC7902 and LSI sym53c8xx in both cases the read performance is close to 60 mb/sec when I use rh 9.0 with kernel 2.4.20-18.9smp and it is just 40 mb/sec when I use rh 9.0 with kernel 2.4.21-1.1931.2.414.entsmp ( from rhel 3.0 beta 2 ws i386 ) Cheers, Winfrid could you do a 'vmstat 1 > vmstat.log' during the rio testrun and attach the results here - are the writes steady? Created attachment 94553 [details]
vmstat for rh 9.0 with kernel 2.4.20-18.9smp
Here are the requested output files ( vmstat 1 ) for READ of rio.
Note : Adaptec provides now new drivers for aic79xx
This run was done using aic79xx-2.0.2
while it probably doesn't matter in this case, I would like to urge you to ONLY report bugs with drivers we shipped. Created attachment 94554 [details]
output of vmstat 1 for kernel 2.4.21-1.1931.2.423entsmp
can you check if it gets better if you do echo 127 > /proc/sys/vm/max-readahead The problem is not the WRITE, the write is almost the same for both kernels, but the READ is better for the kernel 2.4.20-18.9smp. On the 2.4.21 kernel the READ performance is worse even compared with the WRITE performance. I think, that for an EXT3 filesystem seq. READ must be better than WRITE. Winfrid Hello Arjan, The read performance is now improved, 47.5 mb/sec instead of 43 mb/sec. But in case of 2.4.20-18.9smp I had 54 mb/sec. The note with the new driver was just an information, that rh should consider this driver for the new kernels . Regards, Winfrid *** This bug has been marked as a duplicate of 104633 *** An errata has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2004-188.html |