Arch Linux

fattoony

Member

Registered: 2015-02-07

Posts: 3

LVM disk power management

Hi,
I have 3 physical disks forming one volume group, with one logical volume.
If i try to issue a standby command to the logical volume..

sudo hdparm -y /dev/mapper/VG0-LVstorage

/dev/mapper/VG0-LVstorage:

 issuing standby command

 HDIO_DRIVE_CMD(standby) failed: Inappropriate ioctl for device

But if i issue a standby command to the individual disks in the volume group..

sudo hdparm -y /dev/sda1 /dev/sdb1 /dev/sdc1

/dev/sda1:

 issuing standby command

/dev/sdb1:

 issuing standby command

/dev/sdc1:

 issuing standby command

This works fine!
Is this the normal way to to spin down the disks in a lvm volume group or will this cause file corruption.

And if not can anybody suggest a safe way to achieve this or is it just not possible to spin down disks in a lvm.

Kind regards,

Drew

alphaniner

Member

From: Ancapistan

Registered: 2010-07-12

Posts: 2,810

Re: LVM disk power management

Only physical devices are valid targets for hdparm, so the error you got running it on an LV makes sense.

As for the safety of spinning down disks in an active LV... if I were you I'd ask on the LVM mailing list. Though, if you're using three disks for one LV, I think you'd be better off with mdadm and a RAID providing some redundancy.

---

But whether the Constitution really be one thing, or another, this much is certain - that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist.
-Lysander Spooner

fattoony

Member

Registered: 2015-02-07

Posts: 3

Re: LVM disk power management

Thanks alphaniner,

Will check out LVM mailing list.
As for redundancy, I will be using btsync to mirror the content to 3 physical locations.