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Groups > comp.sys.mac.system > #119587
| From | Stephen Hoffman <seaohveh@hoffmanlabs.invalid> |
|---|---|
| Newsgroups | comp.sys.mac.system |
| Subject | Re: APFS on HDD |
| Date | 2018-11-19 11:34 -0500 |
| Organization | HoffmanLabs LLC |
| Message-ID | <psuolt$ov3$1@dont-email.me> (permalink) |
| References | (8 earlier) <LbiHD.830546$3L2.818742@fx44.iad> <psn38s$307$1@dont-email.me> <RWJHD.307536$rK2.124531@fx28.iad> <1nyf1cp.1xsp53r4hod6uN%dempson@actrix.gen.nz> <BTlID.572643$sO2.508519@fx41.iad> |
On 2018-11-18 22:40:33 +0000, JF Mezei said: > ...APFS basically placed the boot information (block location, number > of blocks to load etc) in block 0 of the GPT partition where the EFI > firmware would look to see if the GPT partition was bootable. The boot block is a protective MBR, and the rest of the GPT "show" is the GPT structures, and the MBR/GPT covers a range of blocks at the lowest-numbered addresses, and the GPT another range of blocks at the upper-addressed end of the device. The latter upper-address-range-usage does get one operating system and its support of dynamic volume expansion in trouble, but that's fodder for another discussion. Older disks and SSDs use 512-byte sectors, optical media is 2048-byte sectors and some permit 512-byte, and newer storage is 4096-byte sectors with some having an option to allow 512-byte addressing. GPT uses sector offsets and the the native sector size for the storage device, which means that the boot records within GPT referencing an EFI bootstrap are sector-size-sensitive. Cloning across media means recalculating some offsets and rewriting the GPT. > So from an EFI point of view, it could only see one bootable volume in > the GPT partition that containes the APFS container which may contain > multiple bootable APFS volumes) I've not looked at the available APFS documentation in any detail, nor looked at the macOS internal book's app source code. GPTs can be nested, with GPT and other sub-partitioning schemes possible. So too can (non-protectively-partitioned) MBR, for that matter. The papers from disk forensics folks are another resource for those interested in this level of detail, GPT, APFS, HFS+ or otherwise. If y'all are interested in the GPT, start here: https://developer.apple.com/library/archive/technotes/tn2166/_index.html -- Pure Personal Opinion | HoffmanLabs LLC
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Re: APFS on HDD rs99tl@gmail.com - 2018-11-09 17:32 -0800
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-10 14:42 +1300
Re: APFS on HDD RSORLANDO <rs99tl@gmail.com> - 2018-11-09 18:15 -0800
Re: APFS on HDD Elden <usenet@moondog.org> - 2018-11-09 21:27 -0800
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-10 18:52 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-10 09:11 -0500
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-11 10:08 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-10 17:41 -0500
Re: APFS on HDD nospam <nospam@nospam.invalid> - 2018-11-10 19:18 -0500
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-11 18:03 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-11 13:21 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-12 03:09 +0000
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-12 02:10 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-12 12:32 +0000
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-13 08:14 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-12 20:29 -0500
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-13 18:15 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-13 09:20 -0500
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 02:30 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-12 12:45 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 18:31 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-13 00:04 +0000
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-13 13:46 +1300
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-11 15:55 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-10 23:38 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-11 07:18 +0000
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-11 12:39 -0500
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-12 09:10 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-11 19:26 -0500
Re: APFS on HDD Your Name <YourName@YourISP.com> - 2018-11-12 16:20 +1300
Re: APFS on HDD J Burns <burns@nospam.com> - 2018-11-12 01:46 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-14 02:05 +1300
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-11 07:13 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 02:10 -0500
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 02:02 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-12 21:57 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 18:26 -0500
Re: APFS on HDD Jolly Roger <jollyroger@pobox.com> - 2018-11-13 01:12 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-12 23:44 -0500
Re: APFS on HDD Jolly Roger <jollyroger@pobox.com> - 2018-11-13 18:17 +0000
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-13 19:38 +1300
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-13 10:21 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-13 05:55 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-14 01:28 +1300
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-13 13:40 +0000
Re: APFS on HDD Jolly Roger <jollyroger@pobox.com> - 2018-11-13 18:18 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-13 05:57 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-14 01:28 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-13 13:27 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-14 13:31 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-14 15:33 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-15 12:04 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-15 00:35 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-15 22:24 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-15 12:39 -0500
Re: APFS on HDD Stephen Hoffman <seaohveh@hoffmanlabs.invalid> - 2018-11-16 13:45 -0500
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-16 20:13 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-18 18:37 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-18 17:40 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-19 13:42 +1300
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-19 02:08 +0000
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-19 15:52 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-18 22:31 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-20 13:23 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-19 23:32 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-20 22:05 +1300
Re: APFS on HDD "David B." <"David B"@nomail.afraid.org> - 2018-11-20 09:36 +0000
Re: APFS on HDD André G. Isaak <agisaak@gm.invalid> - 2018-11-20 06:12 -0700
Re: APFS on HDD "David B." <"David B"@nomail.afraid.org> - 2018-11-20 14:28 +0000
Re: APFS on HDD nospam <nospam@nospam.invalid> - 2018-11-20 09:36 -0500
Re: APFS on HDD nospam <nospam@nospam.invalid> - 2018-11-20 08:57 -0500
Re: APFS on HDD "David B." <"David B"@nomail.afraid.org> - 2018-11-20 14:34 +0000
Re: APFS on HDD nospam <nospam@nospam.invalid> - 2018-11-20 09:36 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-19 05:46 +0000
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-19 02:27 -0500
Re: APFS on HDD Stephen Hoffman <seaohveh@hoffmanlabs.invalid> - 2018-11-19 11:42 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-20 13:23 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-19 21:57 -0500
Re: APFS on HDD dempson@actrix.gen.nz (David Empson) - 2018-11-20 16:28 +1300
Re: APFS on HDD JF Mezei <jfmezei.spamnot@vaxination.ca> - 2018-11-21 13:24 -0500
Re: APFS on HDD Stephen Hoffman <seaohveh@hoffmanlabs.invalid> - 2018-11-19 11:34 -0500
Re: APFS on HDD Lewis <g.kreme@gmail.com.dontsendmecopies> - 2018-11-13 13:41 +0000
Re: APFS on HDD Alan Browne <bitbucket@blackhole.com> - 2018-11-11 13:04 -0500
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