Re: benefits of journaling for soft RAID ?

[Malcolm Beattie]

Matti Aarnio writes:
>       Take another; a popular public FTP site with storage
>       consisting of multiple 30-50 GB RAID5 filesystems.
>       Total capacity around 300 GB.  It crashes for some
>       reason, when will it be online ?  (That is a system
>       where a slow day is 50 GB worth of anonymous FTP
>       traffic.)
> 
>       That FTP site happens to run journaled filesystem,
>       it will be back online in 5 minutes.  (Or then the
>       problem requires hardware service which takes more
>       time..)

The ftp site running a non-journalled ext2 filesystem will be back
in about 13 minutes for multiple 50 GB RAID5 arrays which are nicely
parallelised. Please do some benchmarks, like I have, before just
assuming that fsck takes forever on largish filesystems.
Yes, 5 minutes is faster than 13 minutes but the Solaris boxes I have
which *do* have journalled filesystems still take significantly
longer to boot than my Linux boxes because the rest of the boot is
horribly slow. Solaris seems to take forever prodding its very bits of
hardware before it gets around to booting properly.

--Malcolm

-- 
Malcolm Beattie <[EMAIL PROTECTED]>
Unix Systems Programmer
Oxford University Computing Services