Autor: Przemysław Pawełczyk (warpman_at_friko5.onet.pl)
Data: Thu 12 Nov 1998 - 19:53:36 MET
Dobre pytania
Warpman
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FWIV, I finally got my Aurora beta monday. I installed it yesterday.
The
machine is a Cyrix 200+ with 96 MB of RAM and a RAID 5 array (Mylex
DAC960
PD-3 controller with 32 MB of cache) composed of six 2 gig IBM wide
drives. There was a C: 500 MB DOS partition that I never booted and
made
HPFS for Aurora. Warp 4 remains on D: 1500 MB HPFS ; and E: 8 GB is the
data drive . So for now, all my drives are HPFS. There is no tool to
convert from HPFS to JFS; so I'm making a couple full backup tapes of
the
machine and I will probably be doing the conversion of the E: 8GB
partition to JFS sometime this week.
I think the main problem with booting the JFS is the partition size wrt
BIOS limitations. Depending on the disk controller and system BIOS, it
is
often not possible to boot a partition bigger than 2 GB (my Mylex RAID
controller is one); sometimes it is up to 8 GB, and I'm sure another
BIOS
spec will be develop to allow more than that some day. Since you can
grow
the JFS partitions, potentially they would no longer be bootable.
Also, the JFS can span multiple physical drives - including some that
are
not on a bootable disk controller (BIOS-less).
Those two limitations would make it difficult to explain to a customer
why
he can't grow his JFS partition, not to mention the potential for bugs.
Now, I have another question :
Let's say you create a JFS volume spanning 4 physical drives. You get a
physical failure of one of the drives. If you aren't using RAID 0 or
RAID
5, you've just lost all your data, right ?
Also, let's say you want to upgrade one of the drives to a faster,
larger
one. Can you shrink your JFS volume to remove a physical drive if there
is
enough space left on the other physical drives? If not, it sounds like
JFS
is only good for RAID setups.
In <199811112332.SAA09760_at_hilfy.ece.cmu.edu>, on 11/11/98
at 06:32 PM, "Brandon S. Allbery KF8NH" <allbery_at_KF8NH.APK.NET>
said:
>In message <199811111914.OAA06332_at_mail.ntrnet.net>, swordedg_at_NTRNET.NET
>writes:
>+-----
>| Those that have the Aurora Beta also have the JFS and according to the
>| ones I've heard from, it is not bootable. Performance wise, it screams.
>+--->8
>Not that I find that surprising; IBM already has to support reading FAT
>and HPFS before the OS is loaded, and there's only so much space
>available for boot-time drivers. SunOS and Linux solve that by stamping
>the block addresses of the kernel into the boot block so it doesn't need
>a filesystem driver; Solaris uses a filesystem-specific boot block (risky
>on a PC --- and you'd rather not know what Solaris x86 does); *BSD has a
>UFS boot driver and will only boot from UFS volumes.
>IBM would have to de-support booting from either FAT or HPFS to enable
>booting from JFS. I suspect their big customers would scream bloody
>murder....
>--
>brandon s. allbery [os/2][linux][solaris][japh]
>allbery_at_kf8nh.apk.net system administrator [WAY too many hats]
>allbery_at_ece.cmu.edu carnegie mellon / electrical and computer engineering
>KF8NH
> Kiss my bits, Billy-boy.
-- -------------------------------------------------------------------- Julien Pierre http://www.madbrain.com Theta Band Software LLC http://www.thetaband.com -------------------------------------------------------------------- ===================END FORWARDED MESSAGE=================== -- ================================ OS/2 WARP 4ever Przemysław Pawełczyk (Warpman) Freelance journalist Member of Provisional Board of TeamOS/2 Poland Phone: +48 12 642-13-00 Mail: Os. Centrum B 1/89, 31-927 Kraków, Poland warpman_at_friko5.onet.pl http://friko5.onet.pl/kr/warpman/ ===============================================
To archiwum zostało wygenerowane przez hypermail 2.1.7 : Tue 18 May 2004 - 15:19:13 MET DST