On Thu, Sep 9, 2010 at 9:04 AM, Michael Torrie <[email protected]> wrote:
On 09/09/2010 07:42 AM, Robert LeBlanc wrote:I guess I'm a weird one that never bothers to do Raid or LVM with my
> Maybe not the cleanest, but I tried LVM mirror and didn't like it so much.
> What I did was put in a new drive and set up mdadm with raid 1 and a missing
> drive. Then I pvmoved the LV to the MD device. As soon as it was done I
> pvremoved the old disk and added it to the MD raid set. There is a period of
> time that you are vulnerable while the raid set syncs. After I did the move
> I had to remove one of the disk and it is still running happily. I intend to
> put the other disk back in once I move all my MythTV stuff to my ESXi
> server. Then it will be as easy as just syncing the disks again.
mythtv server. I might do RAID-1 sometime. Myth itself eliminates the
need to do any LVM, really as it can easily handle multiple disks of
various sizes. Of course you don't get the speed increase from
striping, but I don't need that. If my myth disks get full or need
replacing, I just rsync the contents to a new disk, then mount the new
disk into the same location as the old disk and Myth just happily
accommodates the increased space.
Just to be clear, I was only mirroring my root and home file systems with LVM and then mdadm. My MythTV mount point was also on LVM so I could expand beyond one disk, but that was before they came out with Storage Groups or whatever they are called. Since I'm tired of running Mythbackend on my desktop (can't reboot when I want to try a new kernel, etc...) I moved my root and home LVs off the same disks as my Myth recordings. I used LV mirroring before because I didn't want to mirror entire disks, and I wanted to be more flexible if I needed to grow the mirrored LVs and intermix protected and non-protected LVs.
Now that I want to move my Myth recordings to my ESXi server, I can just take out the disks that contain the recordings and put them into my ESXi box and use RDM to access them. I'll pass through my tuner cards straight to the backend VM, and I will liberate my desktop from being a server. I sure hope there is no problem with moving a couple of LVM disks to a new machine and then trying to remove the phantom PVs from remaining VG. I wish there was some way to easily divide and rename VGs, but I haven't found them.
mdadm was much easier than LVM LV mirroring, but I also used mdadm a number of years ago. LVM suggests a minimum of three disks to do mirroring, two for data and one for metadata. You can get by with two, but it's not as fool proof as mdadm. I think mdadm + LVM is much better than mdadm alone now that I've done it and will probably do it this way in the future if I need protected data.
Robert
Now that I want to move my Myth recordings to my ESXi server, I can just take out the disks that contain the recordings and put them into my ESXi box and use RDM to access them. I'll pass through my tuner cards straight to the backend VM, and I will liberate my desktop from being a server. I sure hope there is no problem with moving a couple of LVM disks to a new machine and then trying to remove the phantom PVs from remaining VG. I wish there was some way to easily divide and rename VGs, but I haven't found them.
mdadm was much easier than LVM LV mirroring, but I also used mdadm a number of years ago. LVM suggests a minimum of three disks to do mirroring, two for data and one for metadata. You can get by with two, but it's not as fool proof as mdadm. I think mdadm + LVM is much better than mdadm alone now that I've done it and will probably do it this way in the future if I need protected data.
Robert
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