<div>On 10/4/05, Arjan van de Ven <<a href="mailto:arjanv@redhat.com">arjanv@redhat.com</a>> wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> On Tue, 2005-10-04 at 12:24 -0500, Justin Conover wrote: > tune2fs > -m reserved-blocks-percentage > -r reserved-blocks-count > > If what I have read is correct, -m by default uses 5% of the disk > space for "reserved root use" On my server at home with a /home of > 1TB thats about 50GB of wasted space. > > Is this reserved space actually used by ANYTHING? Like LVM, some kind > of fragmentation? well for emergency root stuff; logging in without any disk space is hard; lots of stuff wants to make temporary files etc. but your second point it true too: most filesystems (ext3 but most others) start to fragment like hell if they go over about 95% full. Think of it this way: if you have half your disk empty, the filesystem can do a proper job of finding non-fragmented space. If only 0.0001% is free, it has almost no freedom of choice, resulting in "you get it in whatever order some things become free". Those are sort of extremes; there's been a bunch of research and the outcome was that 5% free seems to be sort of the turning point in this respect. I suspect that research predates the Tb sized volumes, so I don't know if it maybe is 1% on such volumes, but then again to some extend the freedom needed will scale with the FS size -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBDQsEXpv2rCoFn+CIRAvUXAJ0SH+Pc9eXpinhuBGZ+DM4r5wTCtgCgi+7B hxT89EtumMwOF13z0l0KP9Q= =C5z1 -----END PGP SIGNATURE-----</blockquote><div> This is a vg on the 1TB a 625GB slice, If i'm reading this correctly than I have about 32GB "free" space right? vgdisplay "VolGroup01" --- Volume group --- VG Name VolGroup01 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 5 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 931.53 GB PE Size 32.00 MB Total PE 29809 Alloc PE / Size 20000 / 625.00 GB Free PE / Size 9809 / 306.53 GB VG UUID Lrid7V-3i0U-35SD-zLCU-kDYB-xmGu-r15Y6E df -k /dev/VolGroup01/LogVol00 Filesystem 1K-blocks Used Available Use% Mounted on - 517924 184 517740 1% /dev </div>tune2fs -l /dev/VolGroup01/LogVol00 tune2fs 1.35 (28-Feb-2004) Filesystem volume name: <none> Last mounted on: <not available> Filesystem UUID: 035dc33b-726e-40d0-8425-461f7b9b971b Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file Default mount options: (none) Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 65536000 Block count: 131072000 Reserved block count: 6553280 Free blocks: 33234208 Free inodes: 52339650 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 1017 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 16384 Inode blocks per group: 512 Filesystem created: Sat Aug 27 07:34:52 2005 Last mount time: Sat Aug 27 18:43:05 2005 Last write time: Sat Sep 17 11:20:43 2005 Mount count: 9 Maximum mount count: -1 Last checked: Sat Aug 27 07:34:52 2005 Check interval: 0 (<none>) Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 128 Journal inode: 8 Default directory hash: tea Directory Hash Seed: 8b7d8357-7489-4d3b-92da-8c186ecca90a Journal backup: inode blocks </div>