Bug 254176
| Summary: | Full-virt 32 bit Solaris and FreeBSD guests disk I/O errors under load | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 5 | Reporter: | Richard W.M. Jones <rjones> |
| Component: | xen | Assignee: | Xen Maintainance List <xen-maint> |
| Status: | CLOSED WORKSFORME | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | 5.1 | ||
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i386 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2008-09-09 13:54:42 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: | |||
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Description
Richard W.M. Jones
2007-08-24 16:27:05 UTC
Solaris install seems a lot happier under Fedora 7 (xen-3.1.0-2.fc8), giving a preliminary indication that fixes in the upstream qemu-dm may have improved disk I/O for fullvirt domains. Ignore comment 2. After overnight testing (getting the installed Solaris to apply updates, while the host was under a moderate load), I found that the Solaris guest had crashed with a severely corrupted disk. So Fedora 7 is better but certainly not working. I also tested this with a partition-backed block device instead of file-backed and the same thing corruption happens (Solaris 32 bit full virt guest, Fedora 7 host). This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release. Today I retested Solaris and FreeBSD under QEMU (CVS version) and KVM-36 (Fedora 8 version) in order to see whether upstream versions of the QEMU device model might fix this. Results are mixed-to-good. FreeBSD ------- FreeBSD appears to run perfectly under both QEMU (CVS) and KVM-36. The QEMU case isn't very surprising or interesting because FreeBSD is running so much more slowly, so any race conditions are less likely to occur. However I think the KVM case is significant and may indicate that some different between the old QEMU in Xen & the new(er) QEMU in KVM has fixed this problem. Solaris ------- Solaris also installs and runs perfectly under QEMU. No disk errors shown, again not very surprising because everything is going much more slowly. Under KVM, Solaris does not boot, although I think this is a different problem. It can boot to a shell in single user mode. However a normal boot hangs with a black screen (no messages). (Note that tests are continuing, and early results like this don't necessarily indicate that the problem has completely gone away). I tested FreeBSD under load for 4 days (KVM-36 again) with no disk errors in that time. This request was previously evaluated by Red Hat Product Management for inclusion in the current Red Hat Enterprise Linux release, but Red Hat was unable to resolve it in time. This request will be reviewed for a future Red Hat Enterprise Linux release. |