Re: hot scsi disk resize

Fabien Salvi
2003-03-04T09:31:40Z

Alex Tomas a écrit:
> Hello!
>
> Here is patch to implement hot scsi resize function.
> Modern storage boxes support virtualization feature and
> may change logical volume size online. I think it would
> be great if linux supports such abilities. Look at
> this example:
>
> root@zefir:# dmesg | tail
> scsi0:A:1:0: Tagged Queuing enabled. Depth 32
> SCSI device sda: 2097152 512-byte hdwr sectors (1074 MB)
> SCSI device sda: drive cache: write through
> sda: unknown partition table
> Attached scsi disk sda at scsi0, channel 0, id 1, lun 0
>
> root@zefir:# mount -treiserfs /dev/sda /mnt
>
> root@zefir:# df -Th
> Filesystem Type Size Used Avail Use% Mounted on
> /dev/hda1 ext3 1.9G 1.8G 138M 93% /
> /dev/sda reiserfs 1.0G 33M 991M 4% /mnt
>
> root@zefir:# echo 'scsi rescan 0 0 1 0' >/proc/scsi/scsi
> root@zefir:# dmesg|tail -n1
> SCSI device sda: 20971520 512-byte hdwr sectors (10737 MB)
> root@zefir:# resize_reiserfs /dev/sda
>
> <-------------resize_reiserfs, 2002------------->
> reiserfsprogs 3.6.4
>
> root@zefir:# df -Th
> Filesystem Type Size Used Avail Use% Mounted on
> /dev/hda1 ext3 1.9G 1.8G 138M 93% /
> /dev/sda reiserfs 10G 33M 9.9G 1% /mnt

Well, I also think it's a very important and needed feature for HA systems.
I'm very interested in such things...

But, I thought resize_reiserfs only resize *unmounted* filesystem :
http://www.reiserfs.org/resize_reiserfs.html

Will it work under IO load ?

Reiserfs has a way to do it dynamically while using it, with mount option :
http://www.reiserfs.org/mount-options.html

I've tested this without a lot of success (I encounter a lot of problems).

I'm afraid that even if scsi subsystem support the resize option,
FileSystems won't support it correctly...
Maybe with LVM ?

Did someone test it ?

--
Fabien SALVI Centre de Ressources Informatiques
Archamps, France -- http://www.cri74.org
PingOO GNU/linux distribution : http://www.pingoo.org

-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html