Unable to perform any activities on the FS when doing EMC BCV restore

[Camel_1]

Hi there,

Configuration:
HPUX11i
EMC3930 - SYMAPI version 4.3

The BCV device is currently assigned to a VG and mount to a file system. When I attempted to perform a BCV restore to the STD device, I cannot access the file system. I am wondering is it necessary to umount the file system and export the VG when doing a EMC BCV restore.

Thanks,

Simon

PS: When the BCV pairing is "split" I can access the file system.

[James A. Donovan]

You will need to unmount the filesystem and deactivate the BCV volume group.

When using the symmir command to restore, the end result will be that the BCV and STD devices will again be synchronized.

from the symmir manpage...

restore Restores one or all standard devices in a
device group from one or more BCV devices
that are associated with the group. Depending
upon whether the restore operation is full or
incremental, all or only the changed tracks
are internally copied to the standard device.
While the operation is in progress, the state
of the device pair is 'Restore in Progress'.
When the operation completes, the state
changes to 'synchronized.'

[Camel_1]

Thanks Jim for your quick reply.

Yes I saw that if the BCV pairing status is "Sync" or "Restore in Progress", the BCV device status becomes NR (Not Ready). Is there any way I can still access the BCV device when doing restore, the business does not allow to shutdown the application while the process.

[James Murtagh]

Hi Simon,

Yes, certainly, unmount and deactivate the volume group involved. Taking the filesystem as an example, the superblock will be read in to the buffer cache when the filesystem is mounted and will remain there until the filesystem is unmounted. A BCV restore to a live filesystem will cause the in-memory superblock and on-disk superblock to be out of sync. Even if the restore works and the filesystem is not deactivated by the kernel a call to umount will overwrite the restored information and your filesystem will be corrupt. If the filesystem was in use at the time there are data blocks, inode cache to consider too. I think LVM will handle this better but there is still the possibility of corruption.

Cheers,

James.

[James A. Donovan]

Your application is running while your restoring from the BCV devices???? That doesn't sound too good to me....but anyway, there is no way to access those BCV devices while they are resynchronizing with their STD pairs.

[Geoff Wild]

You should NOT have the standards mounted prior to running the restore....after the restore has started - then you can remount and access the "restoring" data.....

Rgds...Geoff