Building mirrored VMS system disk

[Karen Lee_3]

I'm expecting delivery of a new DS25 with 7.3-2 OS already loaded on one of the internal disks. I want to mirror that system disk with another internal drive.

I can't remember what command i give at the >>> prompt to set up that initial mirror.

thanks for your help

[Ian Miller.]

Are you using VMS Host based shadowing or controller based mirroring?

[Jan van den Ende · Accepted solution]

Ian,

_INTERNAL_ disks, controller-based mirroring? I must have missed that one.

Karen,
to use HBVS (HostBased VolumeShadowing) on you system disk, you boot the system; enter the VOLSHAD license.
Choose _A_ unique DSA ID number, and set (preferably by way of MODPARAMS) SYSGEN params SHADOW_SYS_DISK to 1, and SHADOW_SYS_UNIT to your DSA unit ID.
Now reboot, and your system disk will be a single-member shadow set.
Now
$ MOUNT/SYSTEM /SHADOW=(mem1,mem2)

The first tme the shadow copy will take some time. If you go cluster, you should use another unit i.o a unit that is internal to the same system as shasow member, In that case also, you should ASAP load the 732 HBMM_V0200 patch (which comes with in structions in the release notes) and activate HostBasedMiniMerge.

hth

Proost.

Have one on me.

jpe

[Tom O'Toole]

Don't forget to make sure the system alloclass is non-zero.

[Martin Vorlaender]

Karen,

one DON'T with a shadowed system disk is to *not* enter the MOUNT DSAx/SHADOW command into the system startup files. The boot process automatically locates all the members of a system disk shadow set.

As to why not, please see http://h71000.www7.hp.com/doc/732FINAL/aa-pvxmj-te/00/00/27-con.html

HTH,
Martin

[Ian Miller.]

Jan, re INTERNAL_ disks, controller-based mirroring - if you have a SWXCR/RA230 or modern equivelent this can be done.

[Jan van den Ende]

Ian,

I forgot about that one, but you are right. How likely are they on DS class systems?

Proost.

Have one on me.

jpe

[comarow]

Some of the controllers support hardware
mirroring. The techniques depend on the
controller. Host based shadowing is done
through software.

Consequently, we'd need more specifics.

[Karen Lee_3]

thanks everyone for your help - the answer I was looking for was the 'sysgen' settings - thanks for interpreting my question correctly....