Re: 4Kn drives, allocation block size
Re: 4Kn drives, allocation block size
- Subject: Re: 4Kn drives, allocation block size
- From: Chris Murphy <email@hidden>
- Date: Fri, 15 Mar 2013 11:23:05 -0600
On Mar 15, 2013, at 11:15 AM, Mark Day <email@hidden> wrote:
>
> For volumes in the gigabyte range, the default allocation block size is 4KiB. As you get to terabytes and larger, we start to increase the default allocation block size. I think it was in Mountain Lion that we adjusted the algorithm used by newfs_hfs to determine the default allocation block size. We wanted to pick an allocation block size such that the volume could still grow its total size without running out of allocation blocks (so that if the user had partitioned a large drive, and then decided to merge the partitions, we could simply grow the file system and continue to use the same allocation block size). Off hand, I'm not positive about that growth factor; I think it was 4X.
OK so for a 3TB 4Kn drive, it might be a 16KB allocation block size?
Apparently there are now 4096 logical/4096 physical drives appearing in the wild.
Chris Murphy
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Filesystem-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden