LSM - volmake: No more space in disk group configuration

[Alet Barnard]

What are the LSM limitations in terms of the maximum disk group size, maximum number of volumes etc. We are experiencing problems creating new LSM volumes on a GS1280 v51B (PK4). The Error message: lsm:volassist: ERROR: No more space in disk group configuration.

The default private region of 4096 blocks should allow 8192 LSM objects. We have 109 disks with 1958 subdisks and 1958 volumes and 1958 plexes. All disks only have 1 private region. What am I missing here?

[Michael Schulte zur Sur]

Hi,

it should be enough but to make sure you should add all disks, subdisks, volumes and plexes because the count each.

greetings,

Michael

[Alet Barnard]

We increased the private region to 4*4096 on the disks that store copies of the configuration database. That allowed us to go from 5984 objects (where we got stuck before) to 6000-something. We again ran into errors - this time the error message is: Too many volumes. We have 2192 volumes. I cannot find any limitations on individual objects??? We are still below the 8192 object limit and there are space in the config db for more objects (voldg list gives free > 0 this time).

[Michael Schulte zur Sur]

Hi,

you say 4*4096. I assume you mean you set the size of the private region to 16384 blocks and not the number of configurations to 4. One block can hold two records.

greetings,

Michael

[Alet Barnard]

Yes, we have 4 disks each with a private region of 16384 blocks. This allowed us to create a 1000+ more objects before the second error "too many volumes" stopped us.

The quickest workaround will probably be to create a new diskgroup - but it will be good to understand why these errors occurred and how to fix them.

[Alet Barnard]

We have created a second disk group and moved some volumes around. The original diskgroup will now only allow 934 voumes, the second disk group is still available to create more volumes - now at 1531 volumes. HP recommended to create more disk groups to get to a higher no of volumes.
Will update with new findings.

[Hein van den Heuvel]

I'm curious...

What problem are you trying to solve with those thousands of volumes?
What will you do with the volumes once created?
Raw device usage (Oracle?)
Mount them all individually (UFS? AdvFS?)
Re-combine them (AdvFS? Oracle?)
What are you trying to achieve? (Load balancing? Quotas? Protection????)
Is there a major application which suggests this setup?

Thanks,
Hein.

[Alet Barnard]

It is a major application that suggests this layout. We have now set privlen, nlog and ncopies back to the defaults - deported all, voldisk rm-ed the disks and brought it all back - this time the volume limits for the diskgroups are 1949 and 1977!! curiouser and curioser! HP now analysing "syscheck - escalate". You can reach me at alet.barnard@vcontractor.co.za for final results.

[Hein van den Heuvel]

>> It is a major application that suggests this layout.

Well, you may want to gently raise my questions.
99% sure that that are plain wrong in suggesting this, based on old technology, and old and invalidated scaling understandings.


Seriously, don't just bend over. Ask why?!

Regards,
Hein.