Re: ext3 file system

Richard B. Johnson
2003-12-17T22:22:36Z

On Wed, 17 Dec 2003, jshankar wrote:

> Hello,
>
> Does the ext3 file systems have to wait for the acknowledgement of block of
> data written to the SCSI device before writing the next block of data.
>

No. Many SCSI drives and adapters allow queued commands and disconnect
operation.

> Is there a parallel I/O where the file system goes on writing the block of
> data
> without waiting for the acknowledgement.
>

This is the normal mode of operation.

> Please let me know your opinion.
>
> Thanks
> Jayshankar
>

Normal Unix/Linux file-systems write data to RAM. At some unknown
time, when memory gets tight, some data are written to the device.

Basically with Unix/Linux, you are using a RAM-Disk that overflows
to the physical media. There are special file-systems (journaling)
that guarantee that something, enough to recover the data, is
written at periodic intervals.

Cheers,
Dick Johnson
Penguin : Linux version 2.4.22 on an i686 machine (797.90 BogoMips).
Note 96.31% of all statistics are fiction.