Date: Thu, 19 Jul 2001 21:27:24 +1000 From: "Andrew Hannam" <andrew.hannam@bigfoot.com> To: "Maxim Sobolev" <sobomax@freebsd.org>, <small@freebsd.org> Subject: Re: Extending md(4) to allow it use pre-compressed disk image Message-ID: <009901c11045$d0536a40$0104010a@famzon.com.au> References: <3B52CC08.1B08210F@FreeBSD.org>
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Does this include the necessary utilities to enable it to be written into the kernel so that the (bloated) loader is not needed in a Pico situation ? I would imagine that something like the "write_mfs_in_kernel" utility. You may also need some pre-compression utility so that you know how much space to allocate into the kernel image when building the kernel. ----- Original Message ----- From: "Maxim Sobolev" <sobomax@freebsd.org> To: <small@freebsd.org> Cc: <arch@freebsd.org> Sent: Monday, July 16, 2001 9:12 PM Subject: Extending md(4) to allow it use pre-compressed disk image > Hi folks, > > I extended md(4) driver to allow it use pre-compressed disk image. In > contrast with the current implementation, when loader(8) on loading > decompresses compressed image and holds it uncompressed in the memory, > with new feature loader(8) places compressed image into a memory, > while md(4) decompresses sectors when they are read. This could be > useful to decrease minimal memory requrements on FreeBSD install or in > another cases when memory is scarce. Performance is quite good - even > P133 reads data from such device at 2-2.5MB/s. > > Since standard gzip format is not really suitable for the task I > created an utility that splits original image into clusters (cluster > size could vary), compresses each cluster using zlib and writes > compressed clusters along with information about offset of each > cluster into resulting image. After that compressed image could be put > into the floppy or other media, loaded using loader(8) and accessed > through md(4) as usually. The only difference is that it is impossible > to write into resulting disk. > > I would like to know if there is enough interest in integrating this > feature into base system, please let me know what do you think about > it. > > -Maxim > P.S. Please keep me on the CC list. > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-small" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message
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