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