- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - HP-UX
- >
- Optimum settings for VG parameters
Operating System - HP-UX
1748177
Members
4290
Online
108758
Solutions
Forums
Categories
Company
Local Language
юдл
back
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Discussions
Discussions
Forums
Forums
Discussions
юдл
back
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Blogs
Information
Community
Resources
Community Language
Language
Forums
Blogs
Go to solution
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-29-2001 12:43 PM
тАО08-29-2001 12:43 PM
I've been bit too many times by MAX PE/PV not being high enough to add new larger disks into a VG. The HP-UX mirroring and pvmove functions work great for migrating to new disk technology, but new storage almost always means larger LUNs and I want to think ahead by creating my VGs with parameters large enough for larger LUNs. I know I can change the default parms when creating a VG, but what numbers are safe? If I increase parms like MAX PE/PV, PE Size, MAX PV/VG am I going to loose anything or hurt myself in some other way? For example, why wouldn't you set the MAX PE/PV to the maximum number allowed?
Thanks,
Scott
Thanks,
Scott
Solved! Go to Solution.
3 REPLIES 3
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-29-2001 12:52 PM
тАО08-29-2001 12:52 PM
Solution
It is probably wise to increase the Max PE/PV value, but remember that with that value you need to take into account the PE Size parameter as a part of it. By default PE Size is 4 MB, but this can be increased.
Here is a document that outlines one pitfall you can hit when useing some of the new very large disks and the VG parameters to change to avoid it.
http://us-support2.external.hp.com/cki/bin/doc.pl/sid=1f7629f4070c8e3ec2/screen=ckiDisplayDocument?docId=200000054599371
Here is a document that outlines one pitfall you can hit when useing some of the new very large disks and the VG parameters to change to avoid it.
http://us-support2.external.hp.com/cki/bin/doc.pl/sid=1f7629f4070c8e3ec2/screen=ckiDisplayDocument?docId=200000054599371
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-29-2001 01:04 PM
тАО08-29-2001 01:04 PM
Re: Optimum settings for VG parameters
Hi Scott:
The LVM table size (VGDA) is a factor of the 'max_pe', 'max_pv', 'max_lv' and 'pe_size' parameters. The essential constraint is that the LVM structure defined must fit into one physical disk extent.
Thus, the problem of creating large volume groups can be attacked by by adjusting one or more of the parameters 'max_pv', 'max_pe', 'max_lv' and 'pe_size'.
I'd give consideration to the size of your volume group as opposed to capriciously choosing maximum values.
For instance, with EMC2 disk, I generally have 4MB disk presented to the kernel. Thus, I don't need to inflate 'max_pe' but certainly want to choose a large 'max_pv' to allow my volume group to grow.
Regards!
...JRF...
The LVM table size (VGDA) is a factor of the 'max_pe', 'max_pv', 'max_lv' and 'pe_size' parameters. The essential constraint is that the LVM structure defined must fit into one physical disk extent.
Thus, the problem of creating large volume groups can be attacked by by adjusting one or more of the parameters 'max_pv', 'max_pe', 'max_lv' and 'pe_size'.
I'd give consideration to the size of your volume group as opposed to capriciously choosing maximum values.
For instance, with EMC2 disk, I generally have 4MB disk presented to the kernel. Thus, I don't need to inflate 'max_pe' but certainly want to choose a large 'max_pv' to allow my volume group to grow.
Regards!
...JRF...
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
тАО08-30-2001 12:40 PM
тАО08-30-2001 12:40 PM
Re: Optimum settings for VG parameters
Hello Scott,
whta you need is a current "magic crystal globe", of
course (out of stock, I am afraid, though).
But with a little bit of "common sense" (TM by someone,
I am shure ;-) you can be save for at least a few years
ahead:
How many filesystems will you need at max. in this VG?
=> rounded up that becomes your MAX_LV parameter.
What is the biggest disk you have right now in that VG?
What do you expect do be a "deliverable" disksize for
the next, say, 2 or 3 years be?
=> That becomes the size we have to "tune" for.
What is the amount of diskspace you are permitted to
"waste"? Say, up to 1/1000 of the disk? e.g. up to 31MB
of a 32GB disk?
=> That determines the maximum PE_SIZE.
I do not think you will have a problem in using more
space for a small LV than needed, like a 32MB LV
instead of 10MB one...
How many disks can be connect to your computer?
And if you add some more controllers?
=> That will be the maximum number of PVs, so choose
=> something suiting your possible growth.
What have we got now?
Well, perhaps something like 40 to 50 LVs, possibly
about 100 to 200 PVs and a PE_SIZE of 32 or 64MB
(maximum right now is 256MB, IIRC). The disks you
get (from a HP XP512, perhaps, or an EMC) are most
often sized for about 4 to 8 GB each (which I do not
like, not even the "OPEN-E" of the XPs) or even up to,
say, 100GB per disk (or "LUN").
That would be then
vgcreate -p 200 -l 50 -s 64 -e 2048 /dev/vgBIG ...
And since your PE_SIZE is bigger than 4MB you will NOT
run into problems with many PEs (as some of us did).
If one of your drives crashes next year, say, a 30GB one,
and the smallest disk available as a substitute would be
about 48GB, well, no problem, get it (and you can even
make use of the additional space!).
If you manager decides to buy another RAID and connect
it your your controllers, well, still some PV slots empty in
your VG, aren't they?
I never ever create VGs with PE_SIZEs of less tha 16MB
these days!
Just my ?0.02,
Wodisch
whta you need is a current "magic crystal globe", of
course (out of stock, I am afraid, though).
But with a little bit of "common sense" (TM by someone,
I am shure ;-) you can be save for at least a few years
ahead:
How many filesystems will you need at max. in this VG?
=> rounded up that becomes your MAX_LV parameter.
What is the biggest disk you have right now in that VG?
What do you expect do be a "deliverable" disksize for
the next, say, 2 or 3 years be?
=> That becomes the size we have to "tune" for.
What is the amount of diskspace you are permitted to
"waste"? Say, up to 1/1000 of the disk? e.g. up to 31MB
of a 32GB disk?
=> That determines the maximum PE_SIZE.
I do not think you will have a problem in using more
space for a small LV than needed, like a 32MB LV
instead of 10MB one...
How many disks can be connect to your computer?
And if you add some more controllers?
=> That will be the maximum number of PVs, so choose
=> something suiting your possible growth.
What have we got now?
Well, perhaps something like 40 to 50 LVs, possibly
about 100 to 200 PVs and a PE_SIZE of 32 or 64MB
(maximum right now is 256MB, IIRC). The disks you
get (from a HP XP512, perhaps, or an EMC) are most
often sized for about 4 to 8 GB each (which I do not
like, not even the "OPEN-E" of the XPs) or even up to,
say, 100GB per disk (or "LUN").
That would be then
vgcreate -p 200 -l 50 -s 64 -e 2048 /dev/vgBIG ...
And since your PE_SIZE is bigger than 4MB you will NOT
run into problems with many PEs (as some of us did).
If one of your drives crashes next year, say, a 30GB one,
and the smallest disk available as a substitute would be
about 48GB, well, no problem, get it (and you can even
make use of the additional space!).
If you manager decides to buy another RAID and connect
it your your controllers, well, still some PV slots empty in
your VG, aren't they?
I never ever create VGs with PE_SIZEs of less tha 16MB
these days!
Just my ?0.02,
Wodisch
The opinions expressed above are the personal opinions of the authors, not of Hewlett Packard Enterprise. By using this site, you accept the Terms of Use and Rules of Participation.
News and Events
Support
© Copyright 2024 Hewlett Packard Enterprise Development LP