Parolski.com

Ok, so people who know me, will know that I think RAM is pretty cool stuff, and that you cant really have enough. OK, so you can have enough, but it is very handy stuff.

A register article today was talking about how MetaRAM can now get 288GB of RAM in a single machine. As someone quickly pointed out in the comments, Sun Microsystems have a machine out for almost 2 years now which supports 256GB of RAM. Its an x86 machine called the x4600. Sun also sell a SPARC machine called the M9000. It supports 2TB of RAM. Thats 2000GB of RAM. Oh, and its got 64 processors.

People should really not be surprised that the limit of how much RAM they have, is not to do with their choice of hardware, but rather choice of Operating System. At this time of writing, thew most advanced version of Windows Server 2003 (Datacenter Edition) CAN address up to 2TB of RAM. But because its written for the x86 architecture, you’ll struggle to run it anywhere to address it all. I should imagine that its partly to do with market demand; you can be sure that if customers were crying out for high capacity x86 equipment, the manufacturers would be making it. Maybe Microsoft should make a port of Windows to run on SPARC?

I find that on the whole this is quite typical of Sun. Their hardware can cost more, but it comes out earlier, and its better than kit in the same class. Sort of like Volkswagen or BMW. Higher cost, but higher quality, and more innovation.

In my last post, the files were being written to an IDE hard disks. Now lets see what happens if we write to /tmp instead. Will Solaris cope with ten million files in /tmp? First, if we want to make use of the compression, we need to make a file system:

We make the files (we can use files instead of real disks…):

anton@solaris-devx ~ $ mkfile 100M /tmp/file1
anton@solaris-devx ~ $ mkfile 100M /tmp/file2
and then su to root to make the ZFS file system (mirrored):

# zpool create crazedPool mirror /tmp/file1 /tmp/file2

I should note that for some reason ZFS didn’t make use of the entire file size:

# zfs list crazedPool
NAME USED AVAIL REFER MOUNTPOINT
crazedPool 110K 63.4M 20K /crazedPool

And now the real test. How about a big file? Lets say, 100G?:

anton@solaris-devx dir1 $ time mkfile 100G woot
real 1m21.995s
user 0m0.191s
sys 0m30.308s
And what about 10000 files, each 10M in size?:
anton@solaris-devx dir1 $ i="0"
anton@solaris-devx dir1 $ time while [ $i -lt 10000 ]
> do
> mkfile 10M la0$i
> i=$[$i+1]
> done
real 1m46.789s
user 0m4.665s
sys 0m43.492s

So far, so good. So now lets push the envelope off the desk. Or maybe off a cliff. Lets see what happens when we make a 100TB file with ZFS!

anton@solaris-devx dir1 $ ls -l megaFile
-rw------- 1 anton staff 107374182400000 Mar 15 18:05 megaFile

and the compression ratio?:

anton@solaris-devx tmp $ zfs get compressratio crazedPool
NAME PROPERTY VALUE SOURCE
crazedPool compressratio 1.00x -

hmm, not quite what I was expecting!

I’m sure my readers at some time or another have had the pleasure of installing Windows XP. They will also probably had the pleasure of having to wait 3/4 of an hour for it to finish! Well, there is a solution!

Furthering the idea of putting the disk install image in RAM before installing, why not write to a Virtual hard drive, also in RAM (if your using VirtualBox)! Specify /tmp as the prefix to your disks name in the “Virtual Disk Location and Size” dialogue window. The result? An installation of windows that will reboot in about 15 seconds. Of course, this is good for some tasks, but not all! Your millage will vary!

NOTE01: I would recommend your have at least 3GB of RAM before trying this!

NOTE02: If you want to keep the install for good, you will need to copy it off /tmp before you reboot, otherwise your virtual drive will be gone!

I must admit though, it still wont solve any post-install issues!

Sun has released a new blade module for their Sun Blade 8000 system, the x8450 . With 128GB of RAM in a single module and sixteen hardware threads per module, that means you get 160 threads and 1280GB of RAM in 19 rack units. Pworrrr! If these modules were used in the Sun Blade 8000p, that would give the same performance in just 14 rack units! So in a 42U rack, you can get three of these units in, totaling: 3840GB of RAM, 480 Hardware threads!!!Fantastic! Just make sure you warn your electric supplier!