p.s.   pvscan, vgscan, lvscan should all give you info to let you see what
you built and how the space is used in LVM.

On Tue, Aug 11, 2015 at 1:53 PM, Scott Rohling <[email protected]>
wrote:

> On mainframes - where ECKD DASD comes in smaller chunks then you might be
> used to (2.3 G for 3390-3, etc) -- using LVM (logical volume manager) is
> standard practice.   While there is debate whether root should be in an
> LVM, or things should be separated out (/usr /tmp, etc) --  the essence is
> that can allow you to extend an existing filesystem by adding space to the
> logical volume manager - and then using it's commands (lvextend, et al) to
> extend existing/new logical volumes groups with this space.   Without that
> ability, you'd run into problems when you have a filesystem fill up -- all
> you can do is copy it to a new, bigger space.   'logical volumes' let you
> extend a single filesystem across several physical volumes...   things like
> striping can also come into play, but that's a more advanced topic... it's
> main use is to allow us to use these historically small DASD units to be
> used in multiples for a single filesystem (mount point, whatever).
>
> LVM isn't a mainframe thing -- it's a Linux thing and there's lots of info
> on it via google, etc...
>
> Scott Rohling
>
> On Tue, Aug 11, 2015 at 12:49 PM, Howard V. Hardiman <[email protected]>
> wrote:
>
>> Thanks.
>>
>> So here is my question.  What is LVM and how do I know if I should be
>> using it?  I did not use LVM on the install I am currently using.  I
>> portioned the single dasd for 'swap' (384k) and '/' (7G).  I did not use
>> LVM after that.
>>
>> I just now did a fresh install where I portioned the dasd the same way as
>> before, but I selected LVM and portioned that way.  I suppose it worked.  I
>> will retry the steps below to add additional dasd since they seem to be
>> geared towards LVM.
>>
>> I'm asking about LVM because based on the responses, it just seems that's
>> the easiest way to go...
>>
>> Comments?
>>
>> HH
>>
>> -----Original Message-----
>> From: Linux on 390 Port [mailto:[email protected]] On Behalf Of
>> Grzegorz Powiedziuk
>> Sent: Tuesday, August 11, 2015 12:27 PM
>> To: [email protected]
>> Subject: Re: Adding DASD to a Debian guest
>>
>> It should be possible depending on what you did so far.
>> If your “/“ is on LVM then you should be able to add new dasd to it’s
>> volume group and extend the logical volume where “/“ lives.
>>
>> Make sure that when you restart linux, these dasd will automatically show
>> up in /proc/dasd/devices Stephen suggested over here creating these empty
>> files in /etc/sysconfig/hardware  - I don’t know about that. I have never
>> done it this way (but I haven’t been using debian in many years and things
>> might have changed). As far as I remember, adding disks to zipl.conf and
>> running zipl command was sufficient. But I googled it and it seems like
>> that is something that came out with “wheeze debian” you might want to
>> follow that than.
>>
>>   cd /etc/sysconfig/hardware
>>    touch config-ccw-0.0.XXXX   (0.0.0201 for example)
>> At this point it would be good to rebuild the initramfs
>>    update-initramfs -uk $(uname -r)
>> Reboot and make sure new dasd are there  (cat /proc/dasd/devices or
>> lsdasd)
>>
>> Create new partition on every new disk
>> fdasd /dev/dasdc for example. And then “n” for new and follow instruction
>> to create a partition using all space on a device.
>> Now you should be able to create new physical volumes out of partitions
>> you’ve just created.
>>
>> pvcreate /dev/dasdc1
>>
>> run pvscan to see if new pv is on the list
>>
>> Now you can extend the volume group.
>> Run vgdisplay to see what is the name of your current VG and then
>>
>> vgextend NAME_of_vg /dev/dasdc1    - this will add "physical volume”
>> dasdc1 on top of your current vg
>>
>> Now you should be able to extend the size of your root logical volume.
>>
>> Run lvdisplay to see what is the name of your root logical volume and then
>>
>> lvextend NAME_of_root_logical_volume /dev/dasdc1    - this will add free
>> space from dasdc1 on top of your root logical volume
>>
>> Now you should be able to extend size of your ext filesystem
>>
>> resize2fs NAME_of_root_logical_volume
>>
>> Repeat steps for every new dasd
>>
>> That should do it. In sles I was able to run resize2fs on a mounted root
>> filesystem, hopefully debian will be happy to do that as well.
>>
>>
>> Gregory Powiedziuk
>>
>>
>> > On Aug 10, 2015, at 8:07 PM, Howard V. Hardiman <[email protected]>
>> wrote:
>> >
>> > Hello,
>> >
>> > I am also working on the system in question in the original question.
>> >
>> > I'm not used to creating  or mounting the partitions using the command
>> line options.  I do that during the install using the text gui.  During
>> that process I partitioned the single dasd for just swap and / .  I'd like
>> know what it takes to simply add more and 'tack it on to the end' of the
>> existing partition, if that's even possible.
>> >
>> > I am able to bring devices online and do the low level format and am
>> able to see the devices in /proc/dasd/devices... But, I could use more
>> detail after that.
>> >
>> > Thanks for any help you can provide.
>> >
>> > HH
>> > -----Original Message-----
>> > From: Linux on 390 Port [mailto:[email protected]] On Behalf Of
>> > Grzegorz Powiedziuk
>> > Sent: Thursday, August 6, 2015 3:16 PM
>> > To: [email protected]
>> > Subject: Re: Adding DASD to a Debian guest
>> >
>> > Can you see them when you do
>> > cat /proc/dasd/devices   ?
>> > If not than first bring them online (chccwdev -e 0.0.XXXX) and then
>> check again.
>> > If they are there, than you are ready to do a low level format with
>> dasdfmt  /dev/dasdX     (/proc/dasd/devices will tell you which dasdX is
>> that).
>> > After that, create partitions (or not if you don’t want to) with fdasd
>> /dev/dasdX Later you can create LVM (or not if you don’t want to) with
>> pvcreate, vgcreate, lvcreate.
>> > Last step is creating a filesystem with mkfs.ext4  (or ext3) on a new
>> partition or logical volume. And now, you can mount it.
>> >
>> > But you have to know that at this point you are also rewriting cylinder
>> 0 of this DASD  (if it is really attached) so it’s label will change.
>> >
>> >
>> > Let us know if you need more details
>> >
>> > Grzegorz Powiedziuk
>> >
>> >
>> >
>> >> On Aug 6, 2015, at 3:04 PM, Cameron Seay <[email protected]> wrote:
>> >>
>> >> of course Debian can't see it until it's in a Linux filesystem. We
>> >> don't know how to format it while in Debian.
>> >
>> >
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