December 20, 201213 yr Trying to diagnose my terrible write speeds at the moment. I'd like to make a 2/3GB ram disk so I can test raw read/write speeds to it via the network, the differences between Big Packets and AFP/SMB. I've tried the normal (googled) methods with no success so can someone point me in the right direction? Cheers!
December 20, 201213 yr Enter the following on the server: mkdir /tmp/test ln -s /tmp/test /mnt/disk1/test chown nobody:users /tmp/test chown nobody:users /mnt/disk1/test Connect to the disk1 share as a guest. Reading and writing the the test directory will go to the RAM disk. Don't write too much or RAM will fill and the system will crash.
December 21, 201213 yr Author Thanks, Unfortunately OS X thinks it is an alias, not a folder that I can write to. Is there a way of making /tmp/test a mountable disk like I can with boot, disk1, etc? Otherwise I can't think of a way of benchmarking this!
December 21, 201213 yr That's odd. It shows up as a regular directory in my Finder. Using SMB it works with AFP it does not work.
December 22, 201213 yr Author That's odd. It shows up as a regular directory in my Finder. Using SMB it works with AFP it does not work. I'll give it another bash. Is there anyway of making a mountable disk?
December 22, 201213 yr That's odd. It shows up as a regular directory in my Finder. Using SMB it works with AFP it does not work. I'll give it another bash. Is there anyway of making a mountable disk? Yes, several http://www.thegeekstuff.com/2008/11/overview-of-ramfs-and-tmpfs-on-linux/ mkdir /tmp/concorde mount tmpfs /tmp/concorde -t tmpfs chown nobody:users /tmp/concorde chmod 777 /tmp/concorde You can make the mount-point anywhere you like, even possibly under an existing shared drive so you can easily get to it. Or, if you add a few lines to the /boot/config/smb-extra.conf file: [concorde] path = /tmp/concorde and then type smbcontrol smbd reload-config You can then see a new share pointing to your new in-ram temp filesystem. The "mount" command knows how to create the temp file file system, and it automatically will expand to use as much memory as needed but not grow over 1/2 the size of the available RAM. (it will not run you out of RAM, but should be usable for your tests, using only the memory needed for the transferred files)
December 22, 201213 yr Author That's odd. It shows up as a regular directory in my Finder. Using SMB it works with AFP it does not work. I'll give it another bash. Is there anyway of making a mountable disk? Yes, several http://www.thegeekstuff.com/2008/11/overview-of-ramfs-and-tmpfs-on-linux/ mkdir /tmp/concorde mount tmpfs /tmp/concorde -t tmpfs chown nobody:users /tmp/concorde chmod 777 /tmp/concorde You can make the mount-point anywhere you like, even possibly under an existing shared drive so you can easily get to it. Or, if you add a few lines to the /boot/config/smb-extra.conf file: [concorde] path = /tmp/concorde and then type smbcontrol smbd reload-config You can then see a new share pointing to your new in-ram temp filesystem. The "mount" command knows how to create the temp file file system, and it automatically will expand to use as much memory as needed but not grow over 1/2 the size of the available RAM. (it will not run you out of RAM, but should be usable for your tests, using only the memory needed for the transferred files) Getting there now! Two things: 1. How do I get AFP to see this mount point? 2. OS X won't let me write to it when I'm logged in as me, and says it can't be found when I connect as guest!!
December 22, 201213 yr Use SMB for testing. Configure the workgroup on the Mac control panel under Network->Advanced->WINS
December 22, 201213 yr Author Use SMB for testing. Configure the workgroup on the Mac control panel under Network->Advanced->WINS Well SMB maxes out at 60MB/sec where-as SCP maxes out at 85MB/sec. Neither which hit the 120MB/sec I know gigabit ethernet can do.
December 23, 201213 yr Author I only got 60 as well. Not sure why. Glad it isn't just me! I know AFP can go faster, but without a ram disk that AFP can see I can't test that
December 23, 201213 yr I only got 60 as well. Not sure why. Glad it isn't just me! I know AFP can go faster, but without a ram disk that AFP can see I can't test that You probably just need to set the permissions so it can be seen. (I don't have a MAC, nor ever really used one for more than a minute or two, so can't help you there) Joe L.
December 24, 201213 yr I got it working with AFP and the speeds are great. 99Mbps write and 93Mbps read. echo '"/tmp/test" "RAMdisk" dperm:0770 fperm:0660' >> /etc/netatalk/AppleVolumes.default The share should appear in the finder. Mount the share with the Finder. Open a terminal and enter cd /Volumes/RAMdisk Write test: time dd if=/dev/zero bs=1024k of=tstfile count=1024 Read test: dd if=tstfile bs=1024k of=/dev/null count=1024 Take the result and google "98105650 bytes/sec in megabytes/s"
December 25, 201213 yr Author Quick Q: I think I'm getting OS X caching here: File Creation: dd if=/dev/zero bs=128mb of=filename count=1 2>/dev/null File Read: dd if=filename bs=128mb of=/dev/null count=1 #2>/dev/null I get: 1+0 records in 1+0 records out 134217728 bytes transferred in 0.095465 secs (1405937313 bytes/sec) Read: 1145.52 MB/sec That is... quite fast!!
December 26, 201213 yr The size needs to exceed the amount of buffer space the system has. Remember anything *NiX based will use memory for buffering to make disk activity look faster than it really is. For instance on my system writing to a laptop 5400rpm cache drive yields these results. Also note that even when using larger block sizes there is a max amount of bytes it will write for a count of 1 (look at the 4GB and 6GB numbers to see 2.1GB). dd if=/dev/zero bs=128MB of=filename count=1 1+0 records in 1+0 records out 128000000 bytes (128 MB) copied, 0.174808 s, 732 MB/s dd if=/dev/zero bs=1GB of=filename count=1 1+0 records in 1+0 records out 1000000000 bytes (1.0 GB) copied, 1.26024 s, 794 MB/s dd if=/dev/zero bs=2GB of=filename count=1 1+0 records in 1+0 records out 2000000000 bytes (2.0 GB) copied, 2.30195 s, 869 MB/s dd if=/dev/zero bs=4GB of=filename count=1 0+1 records in 0+1 records out 2147479552 bytes (2.1 GB) copied, 2.52188 s, 852 MB/s dd if=/dev/zero bs=6GB of=filename count=1 0+1 records in 0+1 records out 2147479552 bytes (2.1 GB) copied, 2.73846 s, 784 MB/s
December 27, 201213 yr I get 86MB/s dga:~ dga$ cd /Volumes/RAMd/ dga:RAMd dga$ ls -lhS ~/Downloads/ | more total 50437992 -rw-r--r--@ 1 dga staff 3.9G Jul 9 2011 CentOS-6.0-x86_64-bin-DVD1.iso -rw-r--r--@ 1 dga staff 2.9G Sep 7 2010 xcode_3.2.4_and_ios_sdk_4.1.dmg -rw-r--r--@ 1 dga staff 1.8G May 13 2012 M4_Tank_2012.dmg -rw-r--r--@ 1 dga staff 1.7G Jul 13 2011 CM_Battle_for_Normandy.dmg -rw-r--r--@ 1 dga staff 1.1G Jul 9 2011 CentOS-6.0-x86_64-bin-DVD2.iso -rw-r--r--@ 1 dga staff 1.0G Oct 4 09:38 EPSONPrinterDrivers2.12.dmg -rw-r--r--@ 1 dga staff 685M Apr 27 2011 ubuntu-11.04-desktop-i386.iso -rw-r--r--@ 1 dga staff 468M Apr 4 2011 AmericanCivilWar.dmg -rw-r--r--@ 1 dga staff 366M Dec 3 12:33 syslog-1.1 -rw-r--r-- 1 dga staff 362M Mar 29 2012 systemrescuecd-x86-2.5.1.iso -rw-r--r--@ 1 dga staff 352M Feb 15 2011 The_Stroke_of_Midnight.dmg -rwxr-xr-x 1 dga staff 349M Apr 27 2012 syslog-2012-04-27.txt -rw-r--r--@ 1 dga staff 338M Mar 21 2010 MUPromoSpring2010.dmg -rw-r--r--@ 1 dga staff 262M Aug 31 2011 ParallelsDesktop-7.0.14920.689535.dmg -rw-r--r--@ 1 dga staff 237M Apr 23 2008 BCUpdateVista64.exe -rw-r--r--@ 1 dga staff 225M Mar 17 2008 Toast 9 Titanium Upgrade.dmg -rw-r--r--@ 1 dga staff 218M Mar 5 2010 ParallelsDesktop-parallels-en_US-5.0.9344.558741.dmg -rw-r--r--@ 1 dga staff 211M Jul 3 2011 ParallelsDesktop-parallels-en_US-6.0.12092.670880.dmg -rw-r--r--@ 1 dga staff 210M Jun 20 2011 ParallelsDesktop-parallels-en_US-6.0.12090.660720.dmg dga:RAMd dga$ time cp ~/Downloads/EPSONPrinterDrivers2.12.dmg . real 0m11.595s user 0m0.004s sys 0m2.807s dga:RAMd dga$
January 3, 201313 yr Author Managed the following peaks: SMB Read: 60.8 MB/sec Write: 54.6 MB/sec AFP Read: 103.1 MB/sec Write: 110 MB/sec Pretty speedy...
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