Date: Mon, 09 Dec 2019 11:22:38 +0000 From: bugzilla-noreply@freebsd.org To: geom@FreeBSD.org Subject: [Bug 242341] GEOM / GEOM_PART: silent discard MBR modification Message-ID: <bug-242341-14739-a2AWHqCZU0@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-242341-14739@https.bugs.freebsd.org/bugzilla/> References: <bug-242341-14739@https.bugs.freebsd.org/bugzilla/>
next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D242341 --- Comment #5 from Andrey V. Elsukov <ae@FreeBSD.org> --- (In reply to Tomasz "CeDeROM" CEDRO from comment #3) > 1. I would like to clarify why I was unable to write to MBR (first 512 by= tes) of the da1 while there was no problem with writhing to the rest of the= disk? How did you know that? Did you compare the first 512 bytes on both disks af= ter copying? > 2. GEOM_PART: integrity check failed (da1, MBR) <- could that block / dis= card writes to MBR silently? This usually means that parition table's metadata is wrong. If it is wrong,= and kern.geom.part.check_integrity is set, then GEOM_PART just ignores the partition table. > 3. Why `dd if=3D/dev/da0 of=3D/dev/da1` did copy all disk except the MBR? How did you know that? Did you compare the first 512 bytes on both disks af= ter copying? I assume you have disks with different size and GEOM_PART just rej= ects MBR on the copied disk, because its integrity check has failed.=20 > 4. Why I was unable to write to MBR from a file but it was possible to wr= ite that data from a file over md0? Again, how did you know that? --=20 You are receiving this mail because: You are the assignee for the bug.=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-242341-14739-a2AWHqCZU0>