Date: Sat, 26 Sep 2015 09:06:01 -0453.75 From: "William A. Mahaffey III" <wam@hiwaay.net> To: FreeBSD Questions !!!! <freebsd-questions@freebsd.org> Subject: dd question Message-ID: <5606A4FF.4090105@hiwaay.net>
next in thread | raw e-mail | index | archive | help
I am preparing a USB stick for use to install FreeBSD 9.3R on 2 new
boxen I am bringing online. I already had the FreeBSD 9.3R img dd'ed to
that stick last year when I provisioned this box, but for some reason,
when I plugged the stick into my USB port today to copy some additional
files to it (scripts to be used during installs to partition & slice up
HDD's), I got errors in my syslog file & couldn't mount the drive for
the copies. No problema, I'll just re-dd the image to the device & start
over, all I would lose is output from the previous install (this box,
last year this time). However, I notice the dd is proceeding *VERY* slowly:
[root@kabini1, /etc, 8:47:59am] 508 % ll /dev/da0*
crw-r----- 1 root operator 0xd2 Sep 26 08:29 /dev/da0
crw-r----- 1 root operator 0xcd Sep 26 08:29 /dev/da0a
[root@kabini1, /etc, 8:48:09am] 509 % ll
/net/q6600/home/ISOs/BSDs/FreeBSD/9.3/
total 1530556
-rw-r--r-- 1 wam users 178749440 Jul 26 2014
FreeBSD-9.3-RELEASE-amd64-bootonly.iso
-rw-r--r-- 1 wam users 671152128 Jul 26 2014
FreeBSD-9.3-RELEASE-amd64-disc1.iso
-rw-r--r-- 1 wam users 717373440 Jul 26 2014
FreeBSD-9.3-RELEASE-amd64-memstick.img
-rw------- 1 wam users 811 Jul 26 2014 checksum.MD5.txt
[root@kabini1, /etc, 8:48:19am] 510 % dd
if=/net/q6600/home/ISOs/BSDs/FreeBSD/9.3/FreeBSD-9.3-RELEASE-amd64-memstick.img
of=/dev/da0
94834+0 records in
94834+0 records out
48555008 bytes transferred in 542.035379 secs (89579 bytes/sec)
101599+0 records in
101599+0 records out
52018688 bytes transferred in 580.466607 secs (89615 bytes/sec)
I got that output by sending the SIGINFO signal to the dd process from
another shell window. My question is: Why so slow (89-ish KB/s) ? I have
gigabit switched LAN (125 MB/s theoretical speed), & most other file
copies or rsyncs across the LAN go at about 1/3 - 1/2 of theoretical
speeds, which is AOK by me. Any ideas ? TIA & have a nice weekend.
--
William A. Mahaffey III
----------------------------------------------------------------------
"The M1 Garand is without doubt the finest implement of war
ever devised by man."
-- Gen. George S. Patton Jr.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5606A4FF.4090105>