On Fri, Mar 5, 2021, 6:18 PM Greg 'groggy' Lehey wrote: > On Friday, 5 March 2021 at 10:32:15 -0500, Theodore Ts'o wrote: > > On Fri, Mar 05, 2021 at 01:50:32AM -0800, John Gilmore wrote: > >> John P. Linderman wrote: > >>> I have several 12 TB disks scattered about my house. 5% of 12TB is > 600GB. > >> > >> At one point in hystery, ext2 performance was reported to suffer badly > >> if there was less than 5% of disk space available in an active > >> filesystem. My naive belief, probably informed by older and wiser heads > >> around Sun, was that when the file system was >95% full, ext2 spent a > >> lot of time seeking around in free lists finding single allocatable > >> blocks. And there were no built-in "defragmentation" programs that > >> could easily fix that. > > > > I'll point out that BSD FFS, at least in BSD 4.3, reserves 10% of the > > file system for reserved blocks. > > Oops, that's what I get for reading messages sequentially :-( But in > this case it's for small values of 10. > We set this to 1% at Netflix and fill to about ~98-99% full over UFS. This works well as we don't have small files. SATA Flash we keep a bit more empty, but that's due to its crappy FLT liking more free space... Warner Greg > -- > Sent from my desktop computer. > Finger grog@lemis.com for PGP public key. > See complete headers for address and phone numbers. > This message is digitally signed. If your Microsoft mail program > reports problems, please read http://lemis.com/broken-MUA >