[lvm-devel] Batch/queue LVM operations

[Eric Wheeler]

On Fri, 28 Jul 2017, Zdenek Kabelac wrote:

> Dne 28.7.2017 v 21:22 Eric Wheeler napsal(a):
> > Hello,
> > 
> > Is there an option to batch LVM operations?
> > 
> > For example, I would like to delete 100 thin snapshots without updating
> > the vgmeta 100 times.
> 
> You could possibly use --select feature to handle all removals with
> just one lvremove command.

I tried --select, but there is a long pause between removals so it is 
clearly doing a metadata operation for each removal.

Is it possible to do something like this:

1. Hold a lock (how?)
2. vgcfgbackup -f /my-backup/file --ignorelocking-failure
3. Modify /my-backup/file (remove LVs)
4. dmsetup message pool 0 delete ID (each ID)
5. vgcfgrestore --ignorelocking-failure
6. Release lock

--
Eric Wheeler



> 
> > 
> > Same thing with lvcreate, lvresize, etc.
> > 
> > If would be neat if `lvm`'s readline prompt could take multiple commands
> > via stdin and commit them once, even at the expense of longer lock times.
> > 
> > Is there already support for this in some form?
> 
> At this moment we do not have optimization to do more then 1 removal at a time
> - however if  LVs  are 'inactive' before lvremove  it should be relatively
> quick.
> 
> However 'lvm2' was not designed for some ultra-fast manipulation - i.e. you
> are typically not creating/removing LV so quickly.
> 
> Removal of individual thin LVs also takes its time since kernel metadata needs
> to be updated.  So I'd not expect some miliseconds timing.
> 
> 
> Regards
> 
> Zdenek
> 
>