> I was wondering if anyone had any expertise to share about USB hard > drives. I'm finding that access to mine seems terribly slow; far > slower than I think it ought to be. Sound to me like you have a USB 1.1 device. I recall my disk being extremetly slow on USB 1.1 I've since purchased a USB 2 drive enclosure and noticed a substancial increase in performance, though nothing close to a drive on an IDE or SCSI bus. Some things to look at: What file system is the old drive? FAT? Ugh. Try EXT2 for a backup drive. There are serious delete performace gains to be had with EXT2. See here: http://oregonstate.edu/~kveton/fs/page2.php Please note the charts for various kernel versions. It makes some difference in the performance vs fs benchmarks he's got. Are you mounting the disk with 'noatime'? check /etc/fstab or if you're using the cmd line then use '-o noatime' Heres my /etc/fstab line for my usb disk: /dev/sda1 /mnt/usbdisk/boot auto rw,user,noauto,noatime 0 0 I use 'auto' for the fs because sometimes I hook up friends USB drives from their winderz boxen (fat32) UGH! > Is there some tuning or hdparming sort of thing I should do? hdparm is for IDE disks, and does not apply to USB connected devices because they show up as SCSI devices. It is possible that the IDE to USB chip in the box you have does not automatically use DMA to access the drive. This might possibly be due to driver issues in the kernel. I'm guessing here as I am not a kernel guru. I'd suggest upgrading to the 2.6.x series if you're on 2.4 to see if that makes a difference. You can use HDPARM for some things on SCSI disks... Here's a timeing test for my USB2 connected drive. There's not much else you can do with it on SCSI though... (someone please correct me if I'm wrong) # hdparm -Tt /dev/sda1 /dev/sda1: Timing buffer-cache reads: 1276 MB in 2.00 seconds = 637.78 MB/sec Timing buffered disk reads: 60 MB in 3.06 seconds = 19.63 MB/sec That's my 5400RPM 30GB IBM TravelStar [DeathStar?] in a USB2 enclosure. Bottom line, reformat the drive in ext2 if it isn't already and turn off the access time stamping of files with 'noatime' or get a USB2 enclosure... One other side note. The number of files radically affects how long it takes to create/delete things. EXT2 smokes all the journaled FS's in delete performance. (see the charts on the above linked page) On Wednesday 29 September 2004 10:50, rpgoldman at real-time.com wrote: > rm -rf for 3 megabytes: 50 seconds > rm -rf for 5.5 megabytes: 2 minutes 40 seconds! Here's a test for comparison: #find /mnt/usbdisk/home/user/ -name "*" |wc -l 89218 #time rm -rf /mnt/usbdisk/home/user/* real 1m21.367s user 0m4.076s sys 0m4.812s That was 16GB of data in 89218 files... Now you have something "real world" to compare your gains/losses to in your experimentation. Cheers, -- Christopher A. Gahlon There are 10 kinds of people in the world, those that understand binary and those that don't. _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota Help beta test TCLUG's potential new home: http://plone.mn-linux.org Got pictures for TCLUG? Beta test http://plone.mn-linux.org/gallery tclug-list at mn-linux.org https://mailman.real-time.com/mailman/listinfo/tclug-list