Messages in this thread |  | | From | (Harald Koenig) | Subject | Re: ext2fs "performace" | Date | Fri, 21 Jun 1996 07:59:59 +0200 (MET DST) |
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> A 1 GB file on a 1k block ext2 filesystem will have 4096 indirect > blocks and a few dindirect blocks. Deleting the file will involve > essentially doing a random-access seek and read of each of these > blocks, so if it takes 100 seconds you are getting over 40 seeks/reads > per second.
sounds reasonable (sigh;-) and matches the Bonnie result (my bonnie version is from 1991 if this matters):
# time /src/Bonnie/Bonnie File './Bonnie.1200', size: 104857600 Writing with putc()...done Rewriting...done Writing intelligently...done Reading with getc()...done Reading intelligently...done Seeker 1...Seeker 3...Seeker 2...start 'em...done...done...done... -------Sequential Output-------- ---Sequential Input-- --Random-- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU 100 1494 93.0 4652 77.6 1988 70.7 1488 93.3 5193 77.5 55.0 8.7
5:21.76 real, 101.61 user, 102.42 sys, 63% cpu
first I thought it's not possible ramdom seeks take all the time since usually I can hear such seeks on this disk quite good but removing this big file was almost unhearable. mounting this fs (which takes 11sec btw) or running the Bonnie seek test can be "heard" with no problem at all.
Harald -- All SCSI disks will from now on ___ _____ be required to send an email notice 0--,| /OOOOOOO\ 24 hours prior to complete hardware failure! <_/ / /OOOOOOOOOOO\ \ \/OOOOOOOOOOOOOOO\ \ OOOOOOOOOOOOOOOOO|// Harald Koenig, \/\/\/\/\/\/\/\/\/ Inst.f.Theoret.Astrophysik // / \\ \ koenig@tat.physik.uni-tuebingen.de ^^^^^ ^^^^^
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