macOS High Sierra 10.13 and APFS

Yesterday’s Keynote at WWDC confirmed that the next major release of macOS, dubbed High Sierra, will be released this autumn, with developers already being given access to an initial pre-release version.

Although fuller details of the introduction of APFS, the new file system, should be provided later this week, Apple has already answered some of the most important questions which I and others have raised.

Apple has not yet made clear whether High Sierra will require to be started up from an APFS volume, but the intention is that the High Sierra installer will automatically migrate its startup volume to APFS format. Whether the final release will allow users the option to remain with HFS+ remains to be seen, but all the current indications are that upgrading to 10.13 will necessarily include upgrading your startup volume to APFS.

At present, HFS+ volumes which are converted to APFS do so using the case-insensitive variant. Although this should result in fewer problems with folder and file names, as it is more similar to HFS+, I have already explained that this does not come without some pain, particularly for those whose primary language is not English.

At this stage, Apple does not appear to have changed Time Machine backup from its current HFS+-based scheme using hard links, and backup volumes remain in HFS+ format, not APFS. However, APFS does not support the hard links on which Time Machine backups currently depend, and all hard links have to be converted when migrating from HFS+ to APFS. It is unclear whether Apple intends providing an APFS snapshot-based backup scheme with the release of High Sierra later this year, or whether that will follow afterwards.

There is no indication that High Sierra abandons Sierra’s new unified log system, neither is there any indication of Apple making more powerful (or even effective, perhaps) log analysis tools available to developers or users. I can see that Consolation and its derivatives may become a growth area, here at least.

The launch of new iMacs and other announcements are extremely encouraging: Apple seems to be doing many of the right things again. There is also the hope that in High Sierra Apple will fix some of the many annoying bugs and glitches which remain in Sierra. Then there’s Swift 4, before we have even got to proper grips with 3.1, but that’s another story.

Postscript: thanks to @mjtsai who has pointed out that Apple has expressed its intention to make the default macOS file system in 10.13 the case-insensitive variant (which I have corrected above, although I seem to have lost the link in which that was stated). I have also corrected the link above to the article in which I explore the issues which arise in that variant in more detail. If only this was all less confusing…