AIXers,

I need to verify something. It's possible to stripe across different
size disk correct? I know this may sound simple but I wanted to
verify. I have 17GB drives in a raid 0/1 and I want to replace a drive
with a 36GB and restore my stripe set with the 36GB drive.

This can be done without any significant changes correct??

thanks

"Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
news:d526473a.0312041139.6a17e913@posting.google.c om...
> AIXers,
>
> I need to verify something. It's possible to stripe across different
> size disk correct? I know this may sound simple but I wanted to
> verify. I have 17GB drives in a raid 0/1 and I want to replace a drive
> with a 36GB and restore my stripe set with the 36GB drive.
>
> This can be done without any significant changes correct??
>
> thanks

Hallo Ken,

too few information so the answer is a clear 'yeo' ... given that you don't
use a big vg, assuming that you do not create a completely new stripeset and
depending on your vg's PP size you might experience problems with the max
number of PPs in a vg. I.e. a PP size of up to 16MB is too small for a
36GB hdisk. This might force you to use a factor -t. Never did this with a
raid 0/1 myself so I don't know how a raid set behaves in this respect but
if there are problems I would expect them there.
However, you said you are going to "restore" your stripe set... If that
means that you are going to create a new stripe set you could change its
settings before restoring the data to it. In this case I am pretty sure that
everything works out without problems.

HTH,
Andreas

"Andreas Schulze" <b79xan@gmx.de> wrote in message news:<bqpbvg$c197@news-1.bank.dresdner.net>...
> "Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
> news:d526473a.0312041139.6a17e913@posting.google.c om...
> > AIXers,
> >
> > I need to verify something. It's possible to stripe across different
> > size disk correct? I know this may sound simple but I wanted to
> > verify. I have 17GB drives in a raid 0/1 and I want to replace a drive
> > with a 36GB and restore my stripe set with the 36GB drive.
> >
> > This can be done without any significant changes correct??
> >
> > thanks
>
> Hallo Ken,
>
> too few information so the answer is a clear 'yeo' ... given that you don't
> use a big vg, assuming that you do not create a completely new stripeset and
> depending on your vg's PP size you might experience problems with the max
> number of PPs in a vg. I.e. a PP size of up to 16MB is too small for a
> 36GB hdisk. This might force you to use a factor -t. Never did this with a
> raid 0/1 myself so I don't know how a raid set behaves in this respect but
> if there are problems I would expect them there.
> However, you said you are going to "restore" your stripe set... If that
> means that you are going to create a new stripe set you could change its
> settings before restoring the data to it. In this case I am pretty sure that
> everything works out without problems.
>
> HTH,
> Andreas


Andreas,
Thanks for the reply and sorry for the little information, let me give
a little more information and and maybe this will give a clearer
answer.

first off, I was mistaken. I'm using Raid 0 <striping> (not raid 0/1
as I mentioned previously). secondly, I did use the factor -t to
increase the total PP from 1016 to 2032 because I've previously added
a 36gb drive that's NOT part of a stripe group. The 17gb drive that
I'm replacing with a 36gb drive IS part of the stripe set. So, if the
bigger drive can be added to a stripe set of 4-17gb drives will it
work without any recreation of all the filesystems that are going
across those disks??

Hope this clarifies things a little. <smile>

thanks

"Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
news:d526473a.0312051132.1de8cd33@posting.google.c om...
> "Andreas Schulze" <b79xan@gmx.de> wrote in message
news:<bqpbvg$c197@news-1.bank.dresdner.net>...
> > "Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
> > news:d526473a.0312041139.6a17e913@posting.google.c om...
> > > AIXers,
> > >
> > > I need to verify something. It's possible to stripe across different
> > > size disk correct? I know this may sound simple but I wanted to
> > > verify. I have 17GB drives in a raid 0/1 and I want to replace a drive
> > > with a 36GB and restore my stripe set with the 36GB drive.
> > >
> > > This can be done without any significant changes correct??
> > >
> > > thanks
> >
> > Hallo Ken,
> >
> > too few information so the answer is a clear 'yeo' ... given that you
don't
> > use a big vg, assuming that you do not create a completely new stripeset
and
> > depending on your vg's PP size you might experience problems with the
max
> > number of PPs in a vg. I.e. a PP size of up to 16MB is too small for a
> > 36GB hdisk. This might force you to use a factor -t. Never did this with
a
> > raid 0/1 myself so I don't know how a raid set behaves in this respect
but
> > if there are problems I would expect them there.
> > However, you said you are going to "restore" your stripe set... If that
> > means that you are going to create a new stripe set you could change its
> > settings before restoring the data to it. In this case I am pretty sure
that
> > everything works out without problems.
> >
> > HTH,
> > Andreas
>
>
> Andreas,
> Thanks for the reply and sorry for the little information, let me give
> a little more information and and maybe this will give a clearer
> answer.
>
> first off, I was mistaken. I'm using Raid 0 <striping> (not raid 0/1
> as I mentioned previously). secondly, I did use the factor -t to
> increase the total PP from 1016 to 2032 because I've previously added
> a 36gb drive that's NOT part of a stripe group. The 17gb drive that
> I'm replacing with a 36gb drive IS part of the stripe set. So, if the
> bigger drive can be added to a stripe set of 4-17gb drives will it
> work without any recreation of all the filesystems that are going
> across those disks??
>
> Hope this clarifies things a little. <smile>
>
> thanks

Hallo Ken,

with striped disks only and no mirror you cannot exchange disks containing
striped logical volumes on the fly, I am afraid. There is no such command as
'unstripe' AFAIK, so taking away a disk will rip data from your filesystems
and logical volumes killing them that way. You will have to rebuild the
stripe sets from scratch and restore the data from a backup.

Regards,
Andreas

"Andreas Schulze" <b79xan@gmx.de> wrote in message news:<br481g$97h1@news-1.bank.dresdner.net>...
> "Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
> news:d526473a.0312051132.1de8cd33@posting.google.c om...
> > "Andreas Schulze" <b79xan@gmx.de> wrote in message
> news:<bqpbvg$c197@news-1.bank.dresdner.net>...
> > > "Ken" <ucstyle@hotmail.com> schrieb im Newsbeitrag
> > > news:d526473a.0312041139.6a17e913@posting.google.c om...
> > > > AIXers,
> > > >
> > > > I need to verify something. It's possible to stripe across different
> > > > size disk correct? I know this may sound simple but I wanted to
> > > > verify. I have 17GB drives in a raid 0/1 and I want to replace a drive
> > > > with a 36GB and restore my stripe set with the 36GB drive.
> > > >
> > > > This can be done without any significant changes correct??
> > > >
> > > > thanks
> > >
> > > Hallo Ken,
> > >
> > > too few information so the answer is a clear 'yeo' ... given that you
> don't
> > > use a big vg, assuming that you do not create a completely new stripeset
> and
> > > depending on your vg's PP size you might experience problems with the
> max
> > > number of PPs in a vg. I.e. a PP size of up to 16MB is too small for a
> > > 36GB hdisk. This might force you to use a factor -t. Never did this with
> a
> > > raid 0/1 myself so I don't know how a raid set behaves in this respect
> but
> > > if there are problems I would expect them there.
> > > However, you said you are going to "restore" your stripe set... If that
> > > means that you are going to create a new stripe set you could change its
> > > settings before restoring the data to it. In this case I am pretty sure
> that
> > > everything works out without problems.
> > >
> > > HTH,
> > > Andreas
> >
> >
> > Andreas,
> > Thanks for the reply and sorry for the little information, let me give
> > a little more information and and maybe this will give a clearer
> > answer.
> >
> > first off, I was mistaken. I'm using Raid 0 <striping> (not raid 0/1
> > as I mentioned previously). secondly, I did use the factor -t to
> > increase the total PP from 1016 to 2032 because I've previously added
> > a 36gb drive that's NOT part of a stripe group. The 17gb drive that
> > I'm replacing with a 36gb drive IS part of the stripe set. So, if the
> > bigger drive can be added to a stripe set of 4-17gb drives will it
> > work without any recreation of all the filesystems that are going
> > across those disks??
> >
> > Hope this clarifies things a little. <smile>
> >
> > thanks
>
> Hallo Ken,
>
> with striped disks only and no mirror you cannot exchange disks containing
> striped logical volumes on the fly, I am afraid. There is no such command as
> 'unstripe' AFAIK, so taking away a disk will rip data from your filesystems
> and logical volumes killing them that way. You will have to rebuild the
> stripe sets from scratch and restore the data from a backup.
>
> Regards,
> Andreas


Thanks for the reply. I thought you could use a bigger drive but you
clarified things for me. I appreciate it.

Ken wrote:
> "Andreas Schulze" <b79xan@gmx.de> wrote in message news:<br481g$97h1@news-1.bank.dresdner.net>...
>>Hallo Ken,
>>
>>with striped disks only and no mirror you cannot exchange disks containing
>>striped logical volumes on the fly, I am afraid. There is no such command as
>>'unstripe' AFAIK, so taking away a disk will rip data from your filesystems
>>and logical volumes killing them that way. You will have to rebuild the
>>stripe sets from scratch and restore the data from a backup.
>>
>>Regards,
>>Andreas
>
>
>
> Thanks for the reply. I thought you could use a bigger drive but you
> clarified things for me. I appreciate it.

What you can do, is to add the new disk, then use migratepv to move the
PPs of the stripset LV from the old (17G) disk to the new 36G disk.
This will work fine. Although the stripe set will not be able to use
more than 17G of the new disk, you can still use the remaining 19G for
other LVs.

Steve