Bug 174182
Summary: | journal commit starvation | ||||||||
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Product: | Red Hat Enterprise Linux 3 | Reporter: | Bastien Nocera <bnocera> | ||||||
Component: | kernel | Assignee: | Stephen Tweedie <sct> | ||||||
Status: | CLOSED NOTABUG | QA Contact: | Brian Brock <bbrock> | ||||||
Severity: | medium | Docs Contact: | |||||||
Priority: | medium | ||||||||
Version: | 3.0 | CC: | petrides, tao | ||||||
Target Milestone: | --- | ||||||||
Target Release: | --- | ||||||||
Hardware: | All | ||||||||
OS: | Linux | ||||||||
Whiteboard: | |||||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||||
Doc Text: | Story Points: | --- | |||||||
Clone Of: | Environment: | ||||||||
Last Closed: | 2006-12-05 22:51:58 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: | 170417 | ||||||||
Attachments: |
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Description
Bastien Nocera
2005-11-25 14:38:56 UTC
Created attachment 121488 [details]
test.pl
Created attachment 121489 [details]
messages file
ext3 is a journaled filesystem. The journal is a limited resource. If you completely fill the journal, then no more writes can be scheduled, at all; ext2 has no such bottleneck simply because it has no journal. And your test case is the worst-case scenario because you're forcing ext3 to flush out large amounts of data for each transaction, bottlenecking the transaction itself on the data queue. This may not be particularly pleasant but it's largely as expected in this case. It is unlikely we're going to do much work to significantly rebalance the interactions between ext3 and the VM for RHEL-3 at this stage. Is there a major problem being caused here? About 200 users are logged in via ssh to this machine, running text editors, and it would hang for between 10 to 30 seconds when snapshots of the database are taken. Would increasing the size of the journal help? the original information, that ext2 is solving the problem is probably wrong. Although most tests (including this one) were done on RHEL4, the customer did also see a freeze on a ext2 partition - it just came in later. Closing based on last comment. |