wow, that was much smoother than i thought it would be.
I guess setting things up the way i have ahead of time was a good thing.
now to move on to the rest of life. (also an interesting idea to set up a
desktop/laptop this way to see how life works)
lvm> vgs
VG #PV #LV #SN Attr VSize VFree
System 2 1 0 wz--n- 1.02t 1.38g
lvm> pvs
PV VG Fmt Attr PSize PFree
/dev/sda3 System lvm2 a-- 117.38g 1.38g
/dev/sdb2 System lvm2 a-- 922.20g 0
lvm> lvs
LV VG Attr LSize Pool Origin Data% Meta%
Move Log Cpy%Sync Convert
System System Cwi-aoC--- 922.20g [cache] [System_corig] 0.00 0.70
0.00
On Fri, Jul 8, 2016 at 11:24 AM, Stephen Partington <
cryptworks@gmail.com>
wrote:
> The biggest issue i have is that i am working with a mac mini. the 1T
> drive is a 5400 rpm drive. this has been my home server for a while running
> server 2016, but it is time to put something more useful on it.
>
> Part of this is specifically to learn how to use lvm and lvmcache. And
> ram is on the list for this server just not in the budget yet.
>
> I am not worried about catastrophic failure or the like as nothing lives
> on this server that does not already live anywhere else.
>
> I did the install with the Ubuntu server install so i could at least get
> lvm set up partly ahead of time. so it looks like I am in a good place. I
> was reading that article as i received your email.
>
> So now to extend the vg create the cache and meta lv's and turn things on.
>
> lvm> pvscan
> PV /dev/sdb2 VG System lvm2 [922.20 GiB / 0 free]
> PV /dev/sda3 lvm2 [117.38 GiB]
> Total: 2 [1.02 TiB] / in use: 1 [922.20 GiB] / in no VG: 1 [117.38 GiB]
> lvm> pvs
> PV VG Fmt Attr PSize PFree
> /dev/sda3 lvm2 --- 117.38g 117.38g
> /dev/sdb2 System lvm2 a-- 922.20g 0
> lvm> vgs
> VG #PV #LV #SN Attr VSize VFree
> System 1 1 0 wz--n- 922.20g 0
> lvm> vgdisplay
> --- Volume group ---
> VG Name System
> System ID
> Format lvm2
> Metadata Areas 1
> Metadata Sequence No 2
> VG Access read/write
> VG Status resizable
> MAX LV 0
> Cur LV 1
> Open LV 1
> Max PV 0
> Cur PV 1
> Act PV 1
> VG Size 922.20 GiB
> PE Size 4.00 MiB
> Total PE 236082
> Alloc PE / Size 236082 / 922.20 GiB
> Free PE / Size 0 / 0
>
>
> On Fri, Jul 8, 2016 at 11:02 AM, Matt Graham <mhgraham@crow202.org> wrote:
>
>> On 2016-07-08 10:00, Stephen Partington wrote:
>>
>>> 1T spinning disk and 128G SSD installed. [...] going with LVM-Cache
>>> Sadly the Ubuntu server installation does not have the option of
>>> setting up LVM for anything other than its most basic configuration
>>>
>>
>> LVM is complicated, and using LVM-cache is a bit more complicated than
>> just making some PVs and putting them into a VG and then making LVs.
>>
>> What I understand about LVM is that you can build your LVM group and
>>> then migrate/expand it without a full install/wipe or 3rd disk device
>>> to host your core os installation. Can this be done for LVM cache as
>>> well?
>>>
>>
>> Yes. Your setup would be something like this: 2 PVs, one on the fast
>> disk, one on the slow disk[0]. One VG with both PVs in it. Multiple LVs.
>> One named root on the fast disk (mounted at / obviously), one small one
>> named cache-meta on the fast disk, one larger one named cache on the fast
>> disk, and finally one larger one named origin on the slow disk. You'd
>> probably mount the last one on /data or /home or wherever makes sense to
>> put the large amount of stuff you want to serve up. I suppose you could
>> put / on the spinny-disk and use almost all of the SSD for cache too. Your
>> call.
>>
>> If you already have some PVs and LVs set up, you might need to use pvmove
>> and lvresize and resize2fs to resize filesystems and LVs and move them to
>> the appropriate PV. These things are of course doable from a running
>> system and should not cause any problems.
>>
>> https://rwmj.wordpress.com/2014/05/22/using-lvms-new-cache-feature/
>> describes all the commands you'd need to run to make this stuff happen.
>> And getting an additional 4G or 8G of RAM might help more than using an SSD
>> as a cache, depending on what exactly is going on.
>>
>> (I haven't actually tried this, but I've got a 32G unused partition on my
>> SSD right now, and this could be a fun weekend project. I will let you
>> know if I run into any problems.)
>>
>> [0] With 1T disks as cheap as they are, consider a softRAID-1 instead of
>> a single spinny disk. Disk failures are No Fun At All.
>>
>> --
>> Crow202 Blog: http://crow202.org/wordpress
>> There is no Darkness in Eternity
>> But only Light too dim for us to see.
>> ---------------------------------------------------
>> PLUG-discuss mailing list - PLUG-discuss@lists.phxlinux.org
>> To subscribe, unsubscribe, or to change your mail settings:
>> http://lists.phxlinux.org/mailman/listinfo/plug-discuss
>>
>
>
>
> --
> A mouse trap, placed on top of your alarm clock, will prevent you from
> rolling over and going back to sleep after you hit the snooze button.
>
> Stephen
>
>
--
A mouse trap, placed on top of your alarm clock, will prevent you from
rolling over and going back to sleep after you hit the snooze button.
Stephen
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