[daip] LUN/IO failure {External}
Eric Greisen
egreisen at nrao.edu
Mon Jul 13 11:09:55 EDT 2026
I doubt that very much. AIPS has limits as distributed of 90 antennas and 90 IFs. The arrays for processing allow all of the baselines from this and there is no limit on the number of visibilities (I have been working on a data set with over 7000000 visibilities, The limit on number of spectral channels times number of IFs is 132096. I don't have any idea about what is causing your issues. You might try the verb SETMAXAP which may have a smaller limit than required.
Eric
________________________________
From: mz <mgnahz at gmail.com>
Sent: Monday, July 13, 2026 5:16 AM
To: Eric Greisen <egreisen at nrao.edu>
Subject: Re: LUN/IO failure {External}
Dear Eric,
After several random tests, I found that the LUN/IO problem was caused by AIPS reaching its resource limits.
For example, my original uv-data has 561571 visibilities:
AIPS 3: Got(1) disk= 1 user= 15 type=UV MULTI.MSORT.1
AIPS 3: Image=MULTI (UV) Filename=MULTI .MSORT . 1
AIPS 3: # visibilities 561571 Sort order TB
AIPS 3: --------------------------------------------------------------
AIPS 3: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 3: COMPLEX 3 1.000000E+00 1 1.0000E+00 0.00
AIPS 3: STOKES 1 RR 1 -1.0000 0.00
AIPS 3: FREQ 64 2.226053E+09 1* 2.5000E+05 0.00
AIPS 3: IF 16 1.000000E+00 1 1.0000E+00 0.00
AIPS 3: RA 1 00 00 00.000 1 0.000000 0.00
AIPS 3: DEC 1 00 00 00.000 1 0.000000 0.00
AIPS 3: --------------------------------------------------------------
AIPS 3: Max ext file #: HI 1 AT 1 IM 1 CT 1 MC 1
AIPS 3: Max ext file #: PC 1 FQ 1 AN 1 SU 1 CQ 1
AIPS 3: Max ext file #: GC 1 NX 1 TY 1 SN 1 CL 4
I tried to use AVSPC to average the channels within IFs and the number of visibilites reduced to 392374:
AIPS 3: Image=MULTI (UV) Filename=MULTI .CH.0 . 1
AIPS 3: # visibilities 392374 Sort order TB
AIPS 3: --------------------------------------------------------------
AIPS 3: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 3: COMPLEX 3 1.000000E+00 1 1.0000E+00 0.00
AIPS 3: STOKES 1 RR 1 -1.0000 0.00
AIPS 3: FREQ 1 2.233927E+09 1* 1.2000E+07 0.00
AIPS 3: IF 16 1.000000E+00 1 1.0000E+00 0.00
AIPS 3: RA 1 00 00 00.000 1 0.000000 0.00
AIPS 3: DEC 1 00 00 00.000 1 0.000000 0.00
AIPS 3: --------------------------------------------------------------
AIPS 3: Max ext file #: NX 1 HI 1 AT 1 CT 1 FQ 1
AIPS 3: Max ext file #: AN 1 CL 4 CQ 1 GC 1 IM 1
AIPS 3: Max ext file #: MC 1 PC 1 SN 2 SU 1 TY 1
After that, the FRING was happy to fit the data without any LUN/IO complaints. So I am asking: what are the undocumented limits of AIPS on the number of antennas, baselines, visibilites, etc? is there any way to modify them? With regard to my data, I think it is not optimal to average the data either in spectral, temporal, polarizational domain, before frange fitting. So is there any way to partition the data into smaller pieces based on the source set with some AIPS tasks?
Best regards,
Ming
On Sun, 12 Jul 2026 at 01:10, Eric Greisen <egreisen at nrao.edu<mailto:egreisen at nrao.edu>> wrote:
I have no idea. Sometimes a message file gets corrupted and that may be behind this. Go to your first data area and delete the MS file for your user number (or all of them is usually ok). Then start aips again.
Eric
________________________________
From: mz <mgnahz at gmail.com<mailto:mgnahz at gmail.com>>
Sent: Saturday, July 11, 2026 6:28 AM
To: Eric Greisen <egreisen at nrao.edu<mailto:egreisen at nrao.edu>>
Subject: LUN/IO failure {External}
Dear Eric,
Thank you very much for your tip on creating a raw CL table using INDXR last time. Today, when I tried to perform a FRING fit, I obtained a dump of a series of LUN/IO faults, as shown below.
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 12 ALREADY CLOSED IN FTAB ON SEARCH
ZTTYIO: LUN = 6 NOT OPEN IN FTAB
ZMSGCL: LUN = 6 ALREADY CLOSED IN FTAB ON SEARCH
ZMSGDK: LUN = 12 NOT OPEN IN FTAB
I had to press Ctrl+C to close the MSGSRV term before I could return to the AIPS prompt then. Please enlighten me what problem I have encountered and how to handle this. Cheers!
Best regards,
Ming
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