additional http://scyu.logdown.com/posts/519001-ubuntu-lvmcache-setup for anyone else that is interested where this thread goes. On Fri, Jul 8, 2016 at 11:57 AM, Stephen Partington wrote: > And i spoke too soon... > > > http://unix.stackexchange.com/questions/173704/booting-from-an-lvm-cached-volume > > so now to get to a point where i can rebuild this or just reinstall from > scratch... i think the latter might be easier. > > On Fri, Jul 8, 2016 at 11:41 AM, Stephen Partington > wrote: > >> 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 > > 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 >>> 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 >> >> > > > -- > 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