Good Evening...

I am currently working on a project at the office where we are trying to get two of our LBHA's into a solid state device.

Currently I have two SuperMicro 1u's with 1GB of RAM and a 4GB CF card. I have installed CentOS 5.0 on the CF and it works great but CF cards are rated at no more than one million read/writes to the device before they fail.

Is there a HOWTO or a site that I could visit to find out how to get linux to run from RAM and everytime the system is rebooted it will load a fresh copy of Linux into RAM eliminating the possiblity of a failed hard disk.

Thanks in advance!

/bin/false

Isn't CentOS too big to fit into the available RAM? I think that looking into Knoppix may offer some pointers on how to do it. And maybe you could run a liveCD instead of centOS? That would eliminate the CF card entirely - seems the surest way of preventing it from failing.

There is Gigabyte's I-RAM. It uses regular memory with battery backup that connects through SATA. It does not work yet in Linux because the device is missing a few SATA commands in its firmware. Another solid-state hard drive is E-Disk from Bitmicro.

There are other types of non-volatile memory. There is FRAM (ferroelectric RAM). It has unlimited writes. One problem is its maximum capacity is 512 KB. Then there is MRAM and it has the same capacity limits. Companies still think Flash is the best which it is not.

Yes, it is possible to fit a whole OS in RAM. You need to use a 64-bit OS and use ECC 16 GB or more of RAM. Look up /dev/ram on the internet.

Fedora 7's live cd is under 800 mb so I would think one could easily run in 4gb. You might look at how Fedora 7 is doing it because it has the option to run from ram(the version I tried was 64bit). The initial loadup is significant but once up it runs well. Bare minimum is 1gb ram.

Edit:

From the looks of (below) it works for 32bit too.

http://shots.osdir.com/slideshows/sl...se=803&slide=4

Thanks very much for the feedback, I really appreciate it.

It appears it could be a little more difficult than we intended so we may just have to look at alternatives...

Thanks again!

/bin/false

What's an LBHA? It's possible to boot a system off of the network.

An easier thing since you already have it booting fine off the CF card is to simply configure things so that it doesn't write to the card much. Modify /etc/fstab to mount the root partition as ext2 insteand of ext3 and mount it with the "noatime" option. That will get rid of periodic writes for journalling and file (read) access time updating. Remove any references to swap partitions, of course.

Then, add entries in /etc/fstab to mount several directories in tmpfs (in RAM). Here's what I use:

none /tmp tmpfs defaults 0 0
none /var/run tmpfs defaults 0 0
none /var/lock tmpfs defaults 0 0
none /var/tmp tmpfs defaults 0 0

After those modifications, your existing Linux install will not write much to the disk.