Re: Large disks (was Re: bin/19635: add -c for grand total to df(1))
On Thu, 6 Jul 2000, Garrett Wollman wrote: > When creating a large filesystem, it pays to increase the `-c' > parameter as high as newfs will permit. I always do this manually. It should probably be the default for sufficiently large filesystems. Bruce To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Large disks (was Re: bin/19635: add -c for grand total to df(1))
< said: > Maybe this isn't the right list to ask, but stepping into this: > I bought a 30G drive recently, and I was wondering if the 10% 'rule' > for performance is still really needed. I mean, I lose 3 _gigs_ of > storage space, and otherwise the performance detoriates? That > doesn't make sense to me. Yes. The efficiency of the hashing mechanism used to lay out new blocks on the disk depends only on what fraction of the disk is used, not how much space that represents. (On the other hand, it is unlikely that you are significantly stressing the allocator in any meaningful way.) If you're concerned about wasted disk space, there's a lot to be gained by fiddling with the block sizes, bytes per inode, and other layout parameters. Your 30-GB disk probably has a zillion cylinder groups, which is far too many to actually be helpful in disk layout. When creating a large filesystem, it pays to increase the `-c' parameter as high as newfs will permit. -GAWollman To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Large disks (was Re: bin/19635: add -c for grand total to df(1))
On Thu, Jul 06, 2000 at 12:58:27PM +0200, Brad Knowles wrote: [whole discussion about df -h output snipped] > You're ignoring the fact that "Size" is the total physical size > of the device, while "Used", "Avail", and "Capacity" take into > account the 10% (or whatever) overhead that is typically left > unallocated for performance reasons. Maybe this isn't the right list to ask, but stepping into this: I bought a 30G drive recently, and I was wondering if the 10% 'rule' for performance is still really needed. I mean, I lose 3 _gigs_ of storage space, and otherwise the performance detoriates? That doesn't make sense to me. I am running now with reserved set to 2% (on my /home, not on smaller / & /usr of course) and haven't noticed anything of performance loss; of course I haven't managed to fill that ~27G in the short time I have this setup ;) Which also leads me to the question: is it desirable, given those large disks, to have a finer grain of control over reserved space, for example setting reserved space to 2.5% or whatever? Or can this be done already? In the hopes that someone can enlighten me... --Stijn To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
