51–60 of 98 posts
What a great and valuable post, especially since this info is the result of talking to the APFS team at WWDC, and has not been published anywhere else yet. Of particular interest (to me) was the "Checksums" section: Notably absent from the APFS intro talk was any mention of checksums....APFS checksums its own metadata but not user data. ...The APFS engineers I talked to cited strong ECC protection within Apple storag…
What a great and valuable post, especially since this info is the result of talking to the APFS team at WWDC, and has not been published anywhere else yet. Of particular interest (to me) was the "Checksums" section: Notably absent from the APFS intro talk was any mention of checksums....APFS checksums its own metadata but not user data. ...The APFS engineers I talked to cited strong ECC protection within Apple storag…
And in the Sun era you might be prepared to bet your business on not being on the wrong end of a lawsuit from the owner of the various patents and copyrights around Sun IP.
Only a completely insane person would argue that's a good idea now.
What a great and valuable post, especially since this info is the result of talking to the APFS team at WWDC, and has not been published anywhere else yet. Of particular interest (to me) was the "Checksums" section: Notably absent from the APFS intro talk was any mention of checksums....APFS checksums its own metadata but not user data. ...The APFS engineers I talked to cited strong ECC protection within Apple storag…
For example, https://www.google.com/patents/US6289356 was filed in 1998, so I presume it's expiring fairly soon. Given that some of the original lawsuits were Network Appliance suing Sun/Oracle, I'm wondering how much of a role this played in the timing of the release of these features? After all, Apple could pretty much pick a window to release a new file system - nothing special about 2016, that they couldn't have done this in 2015 or 2017...
Which makes me wonder if there are data integrity patents that will expire, and at such time, Apple can now drop the functionality into APFS. After all, they did say during their presentation, that the flexibility of the data format is one of the key design features of APFS.
Earlier quoted context omitted.
Storage is not that cheap yet.
Making backups more granular means you remove sets of backups (or you collapse incremental backups). If a new backup causes corruption to back-propogate then it's not a backup.
I'll go further and say that even backup that forward-propagates corruption is not backup either - all the incremental backups from the moment of corruption are worthless. Bottomline: if your backup cannot be restored with integrity intact - it's not backup!
In my opinion, APFS does not seem to improve upon ZFS in several key areas (compression, sending/receiving snapshots, dedup, etc.). Apple is reimplementing many features already implemented in OpenZFS, btrfs (which itself reimplemented a lot of ZFS features), BSD HAMMER, etc. Maybe extending one of these existing filesystems to add any functionality Apple needs on top of its existing features (and, hopefully, contrib…
APFS is targeted to run on low-powered devices like the Apple Watch. It may be that the alternatives cannot be made suitable for such devices: ZFS is famously memory hungry, HAMMER says it's not designed for < 50GB devices.
From Freebsd Mastery: ZFS Pg 135
"For a rough-and-dirty approximation, you can assume that 1 TB of deduplicated data uses about 5 GB of RAM. You can more closely approximate memory needs for your particular data by looking at your data pool and doing some math. We recommend always doing the math and computing how much RAM your data needs, then using the most pessimistic result. If the math gives you a number above 5 GB, use your math. If not, assume 5 GB per terabyte."
Otherwise I think this is like the myth that ZFS requires expensive ECC ram whereas ECC ram is recommended for any filesystem and zfs needs it no more nor less.
> I get that maybe a checksumming filesystem could conceivably be too computationally expensive for the little jewelry-computers Apple is into these days, but it's a terrible omission on something that is supposed to be the new filesystem for macOS. Checksumming has another cost that isn't immediately obvious. Suppose you write to a file and the writes are cached. Then the filesystem starts to flush to disk. On a con…
Earlier quoted context omitted.
If your backup system involves overwriting old backups, it's not a backup system. It's a data loss system.
Storage is not that cheap yet.
Earlier quoted context omitted.
Storage is not that cheap yet.
Making backups more granular means you remove sets of backups (or you collapse incremental backups). If a new backup causes corruption to back-propogate then it's not a backup.
Earlier quoted context omitted.
Hmm, I guess like there is the "sufficiently smart compiler" falacy, there is now the "sufficently reliable hardware" falacy. But on another level, I guess if hardware fails, then well, you buy more hardware, which is good for Apple. Presumably people who bought in the past from Apple won't turn around and buy an Acer or HP laptop. They'll still buy Apple.
If hardware fails silently, you won't buy more hardware. You'll just come across something odd and say, hmm, typical Apple-bugginess. It would be much nicer if your computer said, “I've detected a bit flip, please restore this file from backup”
What a great and valuable post, especially since this info is the result of talking to the APFS team at WWDC, and has not been published anywhere else yet. Of particular interest (to me) was the "Checksums" section: Notably absent from the APFS intro talk was any mention of checksums....APFS checksums its own metadata but not user data. ...The APFS engineers I talked to cited strong ECC protection within Apple storag…
A lot of the CoW patents, WAFL, snapshot patents that Network Appliance filed in the late 1990s have expired, or are expiring this year. For example, https://www.google.com/patents/US6289356 was filed in 1998, so I presume it's expiring fairly soon. Given that some of the original lawsuits were Network Appliance suing Sun/Oracle, I'm wondering how much of a role this played in the timing of the release of these featu…
No idea if you're right, but it makes Apple's otherwise baffling stance plausible.