Date: Sat, 26 Sep 2015 19:37:51 -0453.75 From: "William A. Mahaffey III" <wam@hiwaay.net> Cc: FreeBSD Questions !!!! <freebsd-questions@freebsd.org> Subject: Re: dd question Message-ID: <56073915.6030707@hiwaay.net> In-Reply-To: <CA%2BtpaK3UOEfKSfSjbdcH%2BR2jaU9=XVBEg%2B%2Bjn5VCbiiUkLF_Tg@mail.gmail.com> References: <5606A4FF.4090105@hiwaay.net> <CA%2BtpaK3UOEfKSfSjbdcH%2BR2jaU9=XVBEg%2B%2Bjn5VCbiiUkLF_Tg@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On 09/26/15 10:25, Adam Vande More wrote:
> On Sat, Sep 26, 2015 at 8:59 AM, William A. Mahaffey III <wam@hiwaay.net>
> wrote:
>
>>
>> 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.
>>
> Hitting Ctrl-T in the dd terminal is a lot easier.
>
>
>> My question is: Why so slow (89-ish KB/s) ?
>>
> Well first off I'd tell dd to use a bigger bs like 1m.
>
>
Update: I tried the dd again w/ 'bs=1m' & it worked much faster:
[root@kabini1, /etc, 7:30:31pm] 535 % dd
if=/net/q6600/home/ISOs/BSDs/FreeBSD/9.3/FreeBSD-9.3-RELEASE-amd64-memstick.img
of=/dev/da0 bs=1m
^T
359+0 records in
359+0 records out
376438784 bytes transferred in 107.540613 secs (3500434 bytes/sec)
424+0 records in
424+0 records out
444596224 bytes transferred in 127.134420 secs (3497056 bytes/sec)
684+1 records in
684+1 records out
717373440 bytes transferred in 208.189064 secs (3445779 bytes/sec)
[root@kabini1, /etc, 7:34:08pm] 536 %
The 'ctrl-T' did not in fact return anything, but the 'killall -SIGINFO
dd' from another shell window did. 3.4-ish MB/s is quite usable, so all
appears well.
--
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?56073915.6030707>