MP 7,1 Use/limitations of using APFS for the Promise 2Ji's disks

bxs

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Oct 20, 2007
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APFS limitations ?

I'm wanting to come to grips with the APFS limitations and have a few questions...

1) Is APFS fully supported for spinning disks of all sizes from 1TB up to say 12 TB ?

2) Is there an Apple document or some other 3rd party document that describes the limitations of how many Containers with multiple Volumes within can be configured on a single physical device, be it an SSD or a spinning disk ?

I'm wanting this information as I intend to use the Promise J2i in a MP7,1 that can hold two spinning disks that I intend to be 12 TB capacities. This will provide some 24 TB of internal direct connected SATA III storage. I do not want to use HFS+ format for these two disks and having to decide, in advance, how to slice the 12 TB space up into various fixed partitions for various known Project uses. Projects come and go, with each having different needs for data storage requirements. I want to use APFS format as it provides a lot more flexibility for dynamic configuration for adding Containers, adding Volumes to the Containers, allowing for Volume space sharing, and for adding completely new/extra Containers as the needs arise going into the future.

I'm told that using APFS vs. HFS+ means giving up some minimal i/o performance loss. This aspect is of no concern to me for my intended use of the Promise 2Ji.

So my big important question is the 1) above.

Thanks...
 
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GamerZer0

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Dec 29, 2019
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I installed two 16GB Seagate EXOS drives in the J2i in RAID O... formatted to Encrypted APFS. I copied some +20TB of content from a Synology NAS. Took over 4 days. All is fine... but a few days after that... the drive wouldn't MOUNT. Tried everything... no use... deleted the whole thing and just formatted the RAID 0 to "Mac OS Extended (Journaled)"... ZERO issues!
 
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bsbeamer

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Sep 19, 2012
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Isn't APFS meant to be used on SSDa only?
According to Apple for Catalina, no. In real world applications, APFS + spinning HDD = more problems than it's worth. Stick with HFS+ for HDDs.


Apple File System (APFS), the default file system for Mac computers using macOS 10.13 or later, features strong encryption, space sharing, snapshots, fast directory sizing, and improved file system fundamentals. While APFS is optimized for the Flash/SSD storage used in recent Mac computers, it can also be used with older systems with traditional hard disk drives (HDD) and external, direct-attached storage. macOS 10.13 or later supports APFS for both bootable and data volumes.
 
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ZombiePhysicist

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May 22, 2014
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This is interesting. One thing I noticed on old spinning hard drives, disk utility will not even let you format APFS. I noticed this on some old 10k velociraptors that I got recently. Weird. Perhaps it's a SATA2 vs 3 thing?
 

bsbeamer

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Sep 19, 2012
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I stick with HFS+ for all non-bootable system drives. Mainly media and working SSDs.

Have several system drive clones that go to portable HDDs, setup through CCC that are APFS volumes. Those are not really "used" on a frequent basis and literally for clone usage only. Only attached to the system when the clone is going to be performed.

Will note that multiple partitions on the same physical HDD drive with APFS is horrendous in this situation. Had a 3TB or 4TB portable HDD drive that was split 50%/50% for cycling clones of a 1TB system drive. It would literally take HOURS to mount in Catalina. Actually thought the drive had failed.

Wiped the drive and tried again without the partitions and it worked flawlessly over and over again (mounting in seconds). Have since switched that particular backup/clone to multiple smaller capacity drives and cycle those for system clones. It's much safer that way anyway, but it was a specific use scenario with repurposing existing hardware.
 

GamerZer0

macrumors newbie
Dec 29, 2019
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It happened to me twice actually... I thought I did something wrong. The OS didn't accept my password to mount the drive. I am sure 100% its correct. Maybe its a bug in Catalina. Anyway... I am happy now with HFS+.

One thing is that the dual drives in the J2i are audible when copying all my files. My Mac Pro sits on my IKEA desk... and I can "feel" the drives if I put my palm on the desk... thought maybe I tightened the whole thing too hard. I did loosen the screws a bit and also placed the Mac Pro on those extra long "gaming" mousepad. Dampens the noise and makes moving the Mac Pro much easier.
 

ZombiePhysicist

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May 22, 2014
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Well isn't this a massive issue? If your main boot drive is an SSD that is APFS formatted, and you back your clone to a spinner, it's either APFS (which seems wonky for spinners) or to an HFS volume, which seems destined to have clone fidelity problems because of different formats.

So the highest fidelity option is to get another SSD for clone backups.
 

GamerZer0

macrumors newbie
Dec 29, 2019
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I use CarbonCopyCloner which never failed me.

Also now my 8bay Synology NAS which was formatted as a "Media" and "Time Machine" folder is now purely Time Machine... all 50TB
 

bsbeamer

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Sep 19, 2012
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Well isn't this a massive issue? If your main boot drive is an SSD that is APFS formatted, and you back your clone to a spinner, it's either APFS (which seems wonky for spinners) or to an HFS volume, which seems destined to have clone fidelity problems because of different formats.

So the highest fidelity option is to get another SSD for clone backups.
In an ideal situation, you'd have multiple matching capacity SSD and identically formatted. It's semi economical for SATA, but becomes cost prohibitive for NVMe for just cycled clone backup usage.

If you're cycling multiple clones, the cheap spinning portable HDDs are more economical for the A/B/C versions. Would recommend a single physical drive for each. The spinning HDD clones setup this way do behave normally. At $40-50 per 1TB drive, almost no excuse not to have them (vs $100-150+ for decent 1TB SATA SSD).

CCC will clone both APFS system drive volumes on the physical drive (the main OS volume and the -data volume) and they recommend cloning to an APFS formatted drive to keep this structure, which is especially important if you're looking for a true bootable clone. You can clone to HFS+ but with Mojave+ you'll run into issues since APFS is the standard for system OS drive.
 

bxs

macrumors 65816
Original poster
Oct 20, 2007
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Seattle, WA
I ended up not using APFS for my J2i HDDs (8TB and 16TB). I used HFS+ for both, and have had no issues at all.

I'm with bsbeamer in that I reserve APFS for SSD media to hold bootable Catalina images exclusively.

I have the Sonnet x16 PCIe card with 4 Samsung blades installed in it; 2TB, and 3x 1TB 970 EVO Plus blades. I partition the 2TB into two 1TB pieces and format one of these 1TB partitions as APFS and use CCC to clone my internal stock Apple 1TB Catalina system. I then RAID-0 the remaining 4x 1TB using HFS+ for high-speed i/o needs. I can use the 1TB Samsung 1TB to hold a previous OS when upgrading to a new released Apple OS for fall-back as required.
 

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