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LD /create/ extend - and still full?

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Willem Grooters
Honored Contributor

LD /create/ extend - and still full?

I have a diskcontainer of 16,800.000 *8 Gb) in size that was filing up to over 85 percent.
I dismounted it's device (LDA1), disconnected the file and extended is by $ LD CREATE/EXTEND/SIZE=33600000 - so doubled it in size.
Next I connected the file and mounted the logical device. $ SHOW DEVICE /FULL now shows twice it's original size, but the percentage of load remains over 85%, feasable since MaxBlocks in SHOW DEVICE is still 16,800,000, so I didn't get new space, appearently.

I didn't notice a way to extend this number - SET DEVICE nor SET VOLUME allows me to change this number. Is there a way to make this extra size available without a backup-init-restore sequence? (I now know LD allows /MAXBLOCK to be used in CREATE, but I noticed AFTER I found the issue. Stupid thinks do happen, occasionally :))
Willem Grooters
OpenVMS Developer & System Manager
Jon Pinkley
Honored Contributor

Re: LD /create/ extend - and still full?

What commands did you use with set volume?

Normally you would use

$ set volume/size lda1:

after extending.

it depends
Hein van den Heuvel
Honored Contributor

Re: LD /create/ extend - and still full?

Be sure to check out $ HELP SET VOLUME /LIMIT


Jon Pinkley
Honored Contributor

Re: LD /create/ extend - and still full?


Hein is correct, if you don't have dynamic volume expansion enabled, increasing the size of the container will not help.

So you will need to do the following (once) after you have created the LD.


a) init lda1: ... /limit ! don't do this now if you didn't originally do it, it will init the device.

b) Enter the following set commands:
$ dism lda1:/cluster
$ mount/ov=id lda1:
$ set volume/limit lda1: ! this extends bitmap.sys and enables dynamic volume expansion
$ dism lda1:

After one of the above is done, then if the disk is expanded, the $ set volume/size command will make the new space available to the volume.

If you do a show dev/ful lda1: you should see logical volume size and expansion limit size, in addition to total blocks.

The logical volume size is what freeblocks is based on, it is the number of blocks available for the volume. The expansion size is the size that the bitmap.sys file is capable of mapping, i.e. the maximum number of clusters that can be in the volume; there is a bit representing each possible cluster. The total blocks is what the device has.

If total blocks is gt expansion limit, then set volume/size can only expand up to the expansion limit. The limit can be adjusted with the set volume/limit command when the disk is mounted privately (by a single process).

What you wrote doesn't seem self consistent:

"$ SHOW DEVICE /FULL now shows twice it's original size" ... "MaxBlocks in SHOW DEVICE is still 16,800,000"

What is now showing "twice it's original size"? My guess is that Total blocks (MAXBLOCK) is now 33600000 and the logical volume size (VOLSIZE) is still 16800000.

Is it really that hard to cut and paste output into your question so we can see what you do?

See attachment for a example of doing what you want (this on Alpha VMS 8.3)

it depends
Willem Grooters
Honored Contributor

Re: LD /create/ extend - and still full?

>Is it really that hard to cut and paste >output into your question so we can see >what you do?

No, but I didn't have the system at hand when I write the entry ;)

There was little opportunity to get to the machine, so that's why it's a belated reply.

This is where I ended up:


Disk $1$LDA1: (DIANA), device type Foreign disk type 1, is online, mounted,
file-oriented device, shareable.

Error count 0 Operations completed 1131427
Owner process "" Owner UIC [WILLEM]
Owner process ID 00000000 Dev Prot S:RWPL,O:RWPL,G:R,W
Reference count 1 Default buffer size 512
Total blocks 33600000 Sectors per track 76
Total cylinders 5818 Tracks per cylinder 76
Logical Volume Size 16800000 Expansion Size Limit 16826368
Allocation class 1

Volume label "WEB_DISK2" Relative volume number 0
Cluster size 4 Transaction count 1
Free blocks 4873268 Maximum files allowed 1680000
Extend quantity 5 Mount count 1
Mount status System Cache name "_$116$DKA100:XQPCACHE"
Extent cache size 64 Maximum blocks in extent cache 487326
File ID cache size 64 Blocks in extent cache 1096
Quota cache size 0 Maximum buffers in FCP cache 1250

Volume Status: ODS-5, subject to mount verification, write-back caching
enabled, special files enabled.

I now note:

Total blocks 33600000 (extended)
Logical Volume Size 16800000 (original)

Ok, that's an explanation, just overlooked that.

I followed the second option by Jon(the only feasable at the moment) to enable volume expansion, followed by SET VOLUME/SIZE=336000000.

Total blocks 33600000 (extended)
Logical Volume Size 33600000 (extended)

Problem solved.

Thanks for putting me on track.
Willem Grooters
OpenVMS Developer & System Manager