Beowulf: Booting from USB Pen Drive

While a bit old, there was an interesting discussion on the beowulf mailing list that started with a posting by p.pennaz on 21 November, 2003, asking about booting a Linux system via a USB cartridge (USB solid-state storage device). USB storage, or any solid state storage for that matter, are very interesting because there's no moving parts and if the power goes out you don't loose your data. There was an immediate response that you should be able to boot from a USB storage device if your motherboard has a BIOS option to support it. Mark Hahn provided some simple ideas about what it would take to boot from a USB storage device. Donald Becker responded that just because a motherboard can boot from a USB storage device doesn't mean it's that easy. Many of the USB storage devices cannot be used for booting.

There are several Linux distributions that can fit onto a USB storage device and allow systems to boot directly from them. In fact, John Hearns pointed out that he has routinely booted systems from a USB memory stick that had StressLinux loaded in it.

Jim Lux also pointed out that there are simple IDE-to-CF (CF=Compact Flash) adapters that allow you to use CF cards as though they are disks. In a later post, Jim also pointed out how nice it could be to boot a diskless cluster node from a CF card using the adapter. This capability would help improve reliability (no moving parts) and reduce heat generation inside a node. Jim's intent is to use these kinds of devices on nodes that only have a wireless network (he doesn't want to ship a kernel and associated parts over a wireless network because of the low bandwidth). Andy Cater reminded everyone that Compact Flash has a number of limited rewrites, so perhaps using the CF card only for the read-only portions of the operating system and a small ramdisk for the portions that readily change (e.g. /var and /tmp).

Solid-state storage is fast becoming very inexpensive thanks to commodity uses (cameras, MP3 players, cell phones, etc.). These devices offer increased reliability and lower power usage and heat generation compared to hard drives. However, they are more expensive and slower (perhaps not an issue for read-only file systems) than hard drives. Overall, sold-state storage has much to offer and may be very useful for clusters.

Jeff Layton has been a cluster enthusiast since 1997 and spends far too much time reading mailing lists. He has been to 38 countries and hopes to see all 192 some day.