lvol time stamps not updated

[Jim Mulshine]

We use raw partitions for a database, where the database writes directly to a LVM logical volume, no file systems involved. In the past it was quite useful when doing a restore from tape to be able to monitor the progess of the restore by moving to /dev/vg01 and typing ll (ls -la). We could see that the restore was writing to the character device files as their time stamps changed, file by file. Also, under normal operation of the database we could see that the time stamps changed. That was in HP-UX 10.20.

However, since we installed HP-UX 11.0 these time stamps do not get updated anymore. Does anyone know why this was changed, what was changed, and is there a way to get 11.0 to behave like 10.20 when it comes to these time stamps?

[Bill Hassell · Accepted solution]

This was a change in LVM code for 11.0 to improve raw disk performance. An internal flag in the kernel has been set that prevents updating the time stamp for raw device files.