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Date: Thu, 07 Feb 2008 15:13:30 +0100 From: Tomasz Chmielewski <mangoo@...g.org> To: LKML <linux-kernel@...r.kernel.org> Subject: why kexec insists on syncing with recent kernels? According to kernel/kexec.c: * kexec does not sync, or unmount filesystems so if you need * that to happen you need to do that yourself. I saw this was true with 2.6.18 kernel (i.e., it didn't sync), but kexec syncs with recent kernels (I checked 2.6.23.14 and 2.6.24): # kexec -e md: stopping all md devices sd 2:0:0:0: [sdb] Synchronizing SCSI cache With kexec on 2.6.18 it was executing a loaded kernel immediately. Generally, it's a good thing to sync before jumping into a new kernel, but it breaks my setup here after upgrading from 2.6.18 to 2.6.24. Why? I have a couple of diskless (iSCSI-boot) machines with a buggy BIOS (old Supermicro P4SBR/P4SBE) which randomly freeze after rebooting (the machine shuts down just fine, but instead of booting again, showing BIOS bootup messages etc. you can just see blank screen). Therefore, I use kexec as a workaround for this rebooting problem. The way kexec works now makes rebooting unreliable again: - network interfaces are brought down, - kernel tries to sync - it never will, as we're booted off network, which is down Any ideas why kexec insists on syncing? -- Tomasz Chmielewski http://blog.wpkg.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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