From: pdh@netcom.com (P D H) Subject: Re: New feature for the filesystems. What do you think ? Date: Mon, 19 Apr 1993 06:25:06 GMT
chuckm@canada.hp.com (Chuck Munro) writes:
>An interesting offshoot of this is the use of a compression chip right
>in the disk controller. The chip is smart enough to recognize inode
>structures as the data is read from the disk. If it sees the compression
>marker, it de-compresses the data in the file *in_hardware* and clears
>the compression marker before the inode data is passed to the CPU.
Is this chip going to make assumptions about what file system I am using?
How long will it take to get the FIRST BYTE of data from the file if the
size of the file is 100 megabytes (compressed)?
What if there is only 2 megabytes of free space?
That compress/decompress chip might do better to be a coprocessor to the
system which can apply the compression/decompression in the appropriate
context.
>Neat idea! The important thing here is that the *file* data is com-
>pressed, *not* the inode data. This is quite unlike the DOS schemes.
The inode is not the big issue. How do you seek to byte #16777216?
>Such an ISO/ANSI filesystem is also portable by design, since filesystems
>created on any computer can be mounted by any other compliant system.
If this is going to be the great universal file system, it is going to
have to have a lot of fantastic features and solve a lot of tricky
problems.
>If someone is tempted to try this, I'd like to suggest that now would
>be a good time to investigate any possible emerging standards *before*
>creating the filesystem code. Since Linux is headed in the POSIX
>direction, keeping up with the standards would be a good thing.
Designing good standards would be as well. With way too many problems
with underlying compression in file systems, I will have my doubts.
When the issues I have mentioned are addressed with solutions then of
course I might believe otherwise.
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