Hi Jay, I can see I will have to be cautious about what I say in this group if you're here too :-)
Thought if I recall correctly I mentioned the fact that for stripping there must always be an equal number of PEs per PV to you ;-) re "Hrm, I wonder if EVMS will resolve this? Or LVM2?" - let's test it ;-) Ciao Mark -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@;VM.MARIST.EDU]On Behalf Of Robert J Brenneman Sent: 23 October 2002 15:51 To: [EMAIL PROTECTED] Subject: Re: FW: striped LVM non-extensible Yeah, multi-striped LVM volumes are 'interesting'. You CAN do a lvextend on multi-striped logical volumes, but it will fail unless you have the same number of blocks available on each PV that the striped LV resides on. Unfortunately, when most people create a striped LV, they make it as large as possible, so there are no free blocks left on the underlying PVs. Thes means that your LV will now behave like a RAID0 array; you'll have to destroy it to make it larger. Hrm, I wonder if EVMS will resolve this? Or LVM2? Jay Brenneman Mark Perry <mark.perry@high-plough-co To: [EMAIL PROTECTED] mputers.de> cc: Sent by: Linux on 390 Port Subject: Re: FW: striped LVM non-extensible <[EMAIL PROTECTED]> 10/22/2002 06:02 PM Please respond to mark.perry Hi Ken, 5 stripes = 5 volumes (PVs) that's it no more to say :-( One solution, if you are using 3390-3 currently, is to add 5 by 3390-9 (or mod 27) to the VG using pvcreate and vgextend, then use pvmove to move each 3390-3 PV to a new 3390-9 PV. Once complete you could, if you wish, use vgreduce to eliminate the 3390-3 from the VG. Then use lvextend to expand the LV by a factor of 3 (or 9 for mod 27). Now I venture into the unknown...... I wonder if it is possible using md (raidtab mkraid) to create 5 seperate md devices (each a set of raid spanning 3390s) and then create a PV out of each of these and then add them as per my suggestion for 3390-9 above. In effect you would get your wish for a very large set of 5 PVs. Hey - I know its way out there but I'm just trying to help ;-) Ciao Mark -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@;VM.MARIST.EDU]On Behalf Of Hall, Ken (ECSS) Sent: 21 October 2002 22:42 To: [EMAIL PROTECTED] Subject: Re: FW: striped LVM non-extensible I work with Phil, and I'm the one who was actually trying to do this. The VG consisted of 5 physical volumes, with one LV, 5 stripes. I added an additional volume, but couldn't extend (insufficient physical extents). After some research, it appeared it might work if I added a total of 5 physical volumes (same as the number of stripes), but that also failed. In the end, I backed up the whole LV, and rebuilt it, but in the process had to make it MUCH bigger (28 volumes). At that point, I couldn't get striping to work at ALL, and finally went with an unstriped volume. I believe there's just something I don't understand about the LVM and striping, but haven't found any explanation. Can anyone shed some light on this? > -----Original Message----- > From: Heinz J . Mauelshagen [mailto:Heinz.Mauelshagen@;T-ONLINE.DE] > Sent: Friday, October 18, 2002 10:11 AM > To: [EMAIL PROTECTED] > Subject: Re: [LINUX-390] FW: striped LVM non-extensible > > > On Thu, Oct 17, 2002 at 08:18:18AM -0500, Montgomery Mouw wrote: > > Heinz, > > > > Do you have any insight on this question? Thanks. > > > > Mo > > > > > -----Original Message----- > > > From: Linux on 390 Port > [mailto:LINUX-390@;VM.MARIST.EDU]On Behalf Of > > > Phil Tully > > > Sent: Thursday, October 17, 2002 7:25 AM > > > To: [EMAIL PROTECTED] > > > Subject: striped LVM non-extensible > > > > > > > > > We have moved a large filesystem to a striped LVM (5 > physical volumes, 5 > > > stripes) and now find that one of the advantages of LVM is lost, > > > non-disruptive expansion. I wanted to make sure I am > correct that a > > > striped LVM can not be expaned without being rebuild? > > Phil, > > a constraint with LVM1 is that stripes can't be extended beyond > physical volumes :-( > > FYI: that constraint won't exist in LVM2 any longer. LVM2 is or new > GPLed code base which will go GA in December and is > avaolable on Linux > 2.4 _and_ 2.5 already. > > LVM2 is fully metadata compatible with LVM1 so that in-place upgrades > _without_ any nasty backup/reconfigure/restore cycles are supported. > > > I see 3 options for you now: > > - if you have free or can free enough extents of other LVs on > your 5 PVs -> use > pvmove to achieve that and extend your stripes on the given PVs > > - if you can add 5 larger PVs to the VG holding the striped LV -> > use pvmove to move the stripes to the bigger PVs and extend > the striped LV > afterwards > > - if LVM2 is an option for you and you can wait for GA -> > that's the way to > go to extend your striped LV because (as mentioned above) > stripes can span > multiple PVs in LVM2 > > > > > > > Phil > > > > > > > > Regards, > Heinz -- The LVM Guy -- > > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > =-=-=-=-=-=-=-=- > > Heinz Mauelshagen Sistina > Software Inc. > Senior Consultant/Developer Am Sonnenhang 11 > 56242 Marienrachdorf > Germany > [EMAIL PROTECTED] +49 2626 141200 > FAX 924446 > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > =-=-=-=-=-=-=-=- >
