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How to discover/choose RAID "Chunk Size"

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1 answer
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question: when using Disk Utility to create a RAID 0 of two external HHD's, it asks to choose a **Chunk size. the options are: 16K, 32K, 64K, 128K, or 256K**. i would like to discover what another two disc external RAID 0 drive has as it came from the factory in order to know which i should choose. but i can't find out what that is. Disk Utility doesn't say, nor in its "Info" window. i even tried using the Terminal command of: **diskutil info /dev/disk3** , but that does not show the Chunk Size either. **are there any other Terminal commands or free Mac apps that would show this info?** --- backstory: fyi: using macOS 13 Ventura on a Macbook Pro M1 Max. i have an older Western Digital My Passport Pro with a Thunderbolt 2 interface (using an Apple Thunderbolt 2 to 3 adapter/dongle). it's the one with 2 HHD's in it. it came setup as RAID 0 but formatted in "Mac OS Extended (Journaled)". i want to reformat it to use "APFS" instead. so using Disk Utility, i deleted the RAID and reformatted the drives. then upon using Disk Utility's RAID Assistant, i selected the RAID type to RAID 0 and selected the two newly reformatted drives. then on the next screen (Set Properties), under where you choose the Name & Format, there's a setting to select a "Chunk Size". i've never seen this option before (granted it's been many many many years since i needed to re-RAID something), and i can't figure out which option to select... the Chunk size options are: 16K, 32K, 64K, 128K, or 256K. everything i've found to read on the subject says that's determined by how big the files you're working with are. to choose a small K when working with large videos & graphics files; and to choose a large K when working with smaller text based files. but what if you have a mix for ALL kinds of files & sizes? what would be the optimal Chunk size for a general purpose drive? yes, i could just choose the middle one (64K) but i don't know if that's optimally average or if leaning to the left or right of middle would be better for such a mix of file types & sizes. i did contact WD support and instead of just telling me what Chunk Size the drives came from the factory set at, their 'only' solution is for me to download/install their disk utility app. i had problems with that app working well two computers ago, so chose to not install it on my previous & current systems. i would rather a solution to be knowledge rather than 'another' app to clutter my mac innards just for this purpose. thanks.
Asked by SyberKnight (519 rep)
May 22, 2023, 03:37 PM
Last activity: May 22, 2023, 07:34 PM