On Wed, 1 Feb 2006, Wolfgang S. Rupprecht wrote: > What is the filesystem overhead percentage supposed to be for FC4 > systems? I have 2 200GB disks attached to the system and I let FC4 do > its thing and claim all of the space for itself. When I do a df(1) I > see that only 279 x 1024^3 bytes are available after overhead. That > comes out to only 71% of the original disk space. Over 128GB is being > lost. Is there really supposed to be that much overhead used? Part of this is because disk size is measured using powers-of-ten units rather than powers-of-two... See http://en.wikipedia.org/wiki/Megabyte for more info. Basically, the disks have 200049647616 bytes each, which is 186 gigabytes ("gibibytes" ???) in powers-of-two land. There's also filesystem overhead, to be sure. Not sure how significant this is, but the ext2/ext3 sparse_super option can help reduce this, especially on large filesystems. LVM probably has some overhead. Note also that it's only 266 * 1024^3 bytes available, not 279. This seems totally crazy still. Where have the other 106GiB gone? Is LVM not using the whole physical volume for some reason? I know the maximum size of LVM volumes can depend on their chunk size. Maybe you are using the wrong chunk size in this particular LVM volume or something. Yea, there's some overhead and miscalculation going on, but still a lot of space not accounted for. Best, -- Elliot > In contrast, on a BSD system under I see only about 5% overhead when > looking at df(1). Thats more in line with what I'd expect for the > space taken by inodes. > > $ fdisk -l > > Disk /dev/sda: 200.0 GB, 200049647616 bytes > 255 heads, 63 sectors/track, 24321 cylinders > Units = cylinders of 16065 * 512 = 8225280 bytes > > Device Boot Start End Blocks Id System > /dev/sda1 * 1 13 104391 83 Linux > /dev/sda2 14 24321 195254010 8e Linux LVM > > Disk /dev/sdb: 200.0 GB, 200049647616 bytes > 255 heads, 63 sectors/track, 24321 cylinders > Units = cylinders of 16065 * 512 = 8225280 bytes > > Device Boot Start End Blocks Id System > /dev/sdb1 * 1 24321 195358401 8e Linux LVM > > $ df > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/mapper/VolGroup00-LogVol00 > 279074448 243021012 21648624 92% / > /dev/sda1 101086 15086 80781 16% /boot > /dev/shm 2024208 0 2024208 0% /dev/shm
