| permalink
My last post was on gPXE (quite a while ago), and I talked about all the amazing possibilities that come from a network boot-loader with that much intelligence.
It looks like these benefits are starting to be realized in a big way. Recently, kernel.org (which hosts the Linux kernel, as well as a ton of mirrors and other projects) released boot.kernel.org. This service has you download a tiny (~500kB) image for USB, CD, or floppy. Stick it on a device and boot from it and you'll have an easy-access menu of various Linux installers, Linux live environments, and test tools.
It's still rough around the edges, and not all the installers work quite right, but it's moving along, and shows a lot of ingenuity. The various environments leverage HTTP, HTTPFS (root filesystem over HTTP), and/or iSCSI.
As an aside, if you want to use their USB image, but still have your stick be able to hold data, it's easy. Just (1) copy existing stuff off, (2) dd the image to the stick as directed on the page, and (3) add a FAT partition back to the stick. Step 3 isn't hard:
$ wget http://boot.kernel.org/gpxe_images/gpxe.usb
...
$ sudo mount /dev/sdd1 /mnt
$ mkdir backup
$ cp -r /mnt/* backup
$ sudo umount /mnt
$ sudo dd if=gpxe.usb of=/dev/sdd
435+0 records in
435+0 records out
222720 bytes (223 kB) copied, 0.159969 s, 1.4 MB/s
$ sudo fdisk /dev/sdd
Command (m for help): p
Disk /dev/sdd: 2063 MB, 2063597056 bytes
64 heads, 32 sectors/track, 1967 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdd4 * 1 2 2032 eb BeOS fs
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (3-1967, default 3): (nothing)
Using default value 3
Last cylinder or +size or +sizeM or +sizeK (3-1967, default 1967): (nothing)
Using default value 1967
Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): b
Changed system type of partition 1 to b (W95 FAT32)
Command (m for help): p
Disk /dev/sdd: 2063 MB, 2063597056 bytes
64 heads, 32 sectors/track, 1967 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdd1 3 1967 2012160 b W95 FAT32
/dev/sdd4 * 1 2 2032 eb BeOS fs
Partition table entries are not in disk order
Command (m for help): w
The partition table has been altered!
...
Syncing disks.
$ sudo mount /dev/sdd1 /mnt
$ cp -r backup/* /mnt
$ sudo umount /mnt
| permalink | related link
I just read up on gPXE, which is an open source alternative to proprietary PXE bootloaders. It supports booting a variety of environments and can be flashed onto NICs or chainloaded from regular PXE.
What struck me was this: it supports HTTP download of both gPXE scripts and binary images. This means that you could set up a web server that gives out gPXE scripts based on a PHP script or other server-side code. The end result is the ability to build a cluster whose nodes boot based on the control of a simple web server. If applied to something like the NCSU VCL, it eliminates the need for disk image transfers: nodes could be configured to run a certain environment by flipping one bit on a web server instead of pushing gigabytes of disk image data.
Furthermore, this isn't just restricted to sickly old NFS boot! gPXE supports software iSCSI boot, so all modern Linux and Windows OSes can get in on the act with just a small amount of configuration.
If I had more time, I'd love to apply this kind of deployment on our research clusters. Just putting the selection of Linux kernels in a centralized place would be a big help, even if we still mount the local disk as root!
| permalink | related link
Ubuntu 8.04 was released earlier this week. You can get it from one of the official mirrors or from our unofficial mirror. This is a "Long Term Support" (LTS) release, meaning that updates will be available for 3 years on the desktop and 5 years for servers.
| permalink | related link
Ubuntu 7.10 was released today. You can get it from one of the official mirrors or from our unofficial mirror. Notable new features include:
- Improved support for multiple monitors, rotatable monitors, etc.
- Plug and play printer detection
- NTFS writing support out-of-box
- Kernel "dynamic ticks", meaning that the kernel doesn't have to wake up 1000 times per second any more, thus saving power.
- Full or partial hard disk encryption selectable at install time
Okay, this still isn't "research" news, but I like it.
| permalink | related link
By way of Ars Technica, we find that Citrix (whose software provides virtual Windows desktop environments accessible anywhere, among other things) has purchased XenSource, the commercial arm of the Xen hypervisor virtualization project. Hopefully they'll make it less of a pain to use and deploy Xen.
Also, VMware went public last Tuesday with a successful IPO. Hopefully they'll keep putting out non-commercial freeware like VMware server and player. Maybe we'll some day seen a free (but likely crippled) version of ESX?
| permalink | related link
By way of slashdot, we find that the Linux kernel (2.6.23 and up) now sports three virtualization techniques out-of-box: KVM, Xen (just merged), and Lguest (also recently merged).
Lguest in particular looks interesting, as it doesn't require virtualization hardware support (like KVM), but is as simple as a single modprobe (as opposed to the Xen behemoth). Performance isn't too great right now, though (-30%).
| permalink | related link
The ext3cow file system has been released for the 2.6 Linux kernel. This extension to ext3 adds "copy on write" (cow) functionality, which in turn allows the user to view the file system as it existed in the past. Unlike fixed checkpointing, this means that a user could dial in any time whatsoever, and see a consistent filesystem from that moment. It would be interesting to see what the performance characteristics of the system are.
If you're interested, you can get it from ext3cow.com; it consists of a kernel patch based on kernel 2.6.20.3, as well as some userland tools.
| permalink | related link
Ubuntu 7.04 was released today. You can get it from one of the official mirrors or from our unofficial mirror.
Okay, maybe this isn't "research" news, but I still like it.
| permalink | related link
Calendar
