https://bugzilla.kernel.org/show_bug.cgi?id=42939 Summary: hv_storvsc - write cache enabled by default and cannot be disabled Product: SCSI Drivers Version: 2.5 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Other AssignedTo: scsi_drivers-other@xxxxxxxxxxxxxxxxxxxx ReportedBy: bugzilla-kernel-org-sux2k0@xxxxxxxxx Regression: No dmesg output: [ 8.080401] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, supports DPO and FUA Question: how safe is my (database) data in the case of a host machine crash or a VM crash? There is no battery-backed writecache installed in the host, just some cheap and slow SATA disks. Another curiosity occurs when running the fio iometer benchmark on the same machine: it gives me 5.000 to 6.000 I/O random access operations per second when using the para-virt hv_storvsc driver, but only the expected 200 I/O ops when using ata_piix via emulation.The kernel in question is version 3.2.11. There doesn't seem to be any way to disable the para-virt device's write-cache. Kernel version is mainline 3.2.11. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
