Ric Wheeler wrote: > Nick Dokos wrote: >> Now that 64-bit e2fsck can run to completion on a (newly-minted, never >> mounted) filesystem, here are some numbers. They must be taken with >> a large grain of salt of course, given the unrealistict situation, but >> they might be reasonable lower bounds of what one might expect. >> >> First, the disks are 300GB SCSI 15K rpm - there are 28 disks per RAID >> controller and they are striped into 2TiB volumes (that's a limitation >> of the hardware). 16 of these volumes are striped together using LVM, to >> make a 32TiB volume. >> >> The machine is a four-slot quad core AMD box with 128GB of memory and >> dual-port FC adapters. >> > Certainly a great configuration for this test.... > >> The filesystem was created with default values for everything, except >> that the resize_inode feature is turned off. I cleared caches before the >> run. >> >> # time e2fsck -n -f /dev/mapper/bigvg-bigvol >> e2fsck 1.41.4-64bit (17-Apr-2009) >> Pass 1: Checking inodes, blocks, and sizes >> Pass 2: Checking directory structure >> Pass 3: Checking directory connectivity >> Pass 4: Checking reference counts >> Pass 5: Checking group summary information >> /dev/mapper/bigvg-bigvol: 11/2050768896 files (0.0% non-contiguous), 128808243/8203075584 blocks >> >> real 23m13.725s >> user 23m8.172s >> sys 0m4.323s >> > > I am a bit surprised to see it run so slowly on an empty file system. > Not an apples to apples comparison, but on my f10 desktop with the older > fsck, I can fsck an empty 1TB S-ATA drive in just 23 seconds. An array > should get much better streaming bandwidth but be relatively slower for > random reads. I wonder if we are much seekier than we should be? Not > prefetching as much? Nick, running this under blktrace would be interesting. Just tracking completions is probably sufficient, use the "-a complete" option.... -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
