My Favorites

Close

Please to see your favorites.

  • Bookmark
  • Email Document
  • Printer Friendly
  • Favorite
  • Rating:

Expected cron daemon behavior change from SLES11 to SLES12

This document (7023601) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 11 (SLES11)
SUSE Linux Enterprise Server 12 (SLES12)
SUSE Linux Enterprise Server 15 (SLES15)

Situation

Attempting to start multiple instances of cron sometimes results in a Resource temporarily unavailable message.

SLES11 only allows one instance of cron (background process) or cron -n (foreground process).
sles11sp4:~ # ps aux | grep cron
root      3341  0.0  0.0  14808   672 ?        Ss   09:11   0:00 /usr/sbin/cron

sles11sp4:~ # cron
cron: can't lock /var/run/cron.pid, otherpid may be 3341: Resource temporarily unavailable

sles11sp4:~ # cron -n
cron: can't lock /var/run/cron.pid, otherpid may be 3341: Resource temporarily unavailable

sles11sp4:~ # ps aux | grep cron
root      3341  0.0  0.0  14808   672 ?        Ss   09:11   0:00 /usr/sbin/cron

SLES12 allows multiple instances of either cron (background) or cron -n (foreground).
sles12sp3:~ # ps aux | grep cron
root      1168  0.0  0.3  18880  2620 ?        Ss   09:40   0:00 /usr/sbin/cron -n

sles12sp3:~ # cron
sles12sp3:~ # cron
sles12sp3:~ # cron -n &
sles12sp3:~ # cron -n &

sles12sp3:~ # ps aux | grep cron
root      1168  0.0  0.3  18880  2620 ?        Ss   09:40   0:00 /usr/sbin/cron -n
root      1269  0.0  0.2  20136  1940 ?        Ss   09:42   0:00 cron
root      1271  0.0  0.2  20136  1940 ?        Ss   09:42   0:00 cron
root      1272  0.0  0.3  20140  2952 pts/0    S    09:42   0:00 cron -n
root      1273  0.0  0.3  20144  2888 pts/0    S    09:42   0:00 cron -n

Resolution

Kindly open a Service Request via SCC and ask for Program Temporary Fix "PTF" ; Fix is available and will be released in future cronie package. 

Cause

SLES12 & SLES15 introduced a defect allowing multiple background and foreground instances of cron to run concurrently.

Status

Reported to Engineering

Additional Information

The expected behavior changed from SLES11 to SLE12 and beyond. The expected behavior is:

SLES11: Only one instance of cron (background) or cron -n (foreground) is allowed. All additional instances will result in resource temporarily unavailable.

SLES12 and SLES15: Only one instance of cron (background) is allowed, but multiple instances of cron -n (foreground) are allowed. All additional instances of cron (background) will result in resource temporarily unavailable. However, multiple instances of cron -n (foreground) are allowed and do not result in a resource restriction.

With new PTF SLES12 and SLES15 behaviour will be like SLES11 ; which means only one cron daemon is running, resulting in jobs not being executed multiple times. 

Maintenance updates newer that cron-4.2-59.3.2 and  cronie-1.4.11-59.3.2 are planned to include the PTF's fix as well.

Note: It is expected that only SLES12SP4 and SLES15 and their successors get the fixed packages. SLES versions and Service Packs proir do not get the fix automatically, but only upon request from customers with valid LTSS (Long Term Service Pack Support) entitlements.

Disclaimer

This Support Knowledgebase provides a valuable tool for NetIQ/Novell/SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.

  • Document ID:7023601
  • Creation Date:20-DEC-18
  • Modified Date:13-MAY-19
    • SUSESUSE Linux Enterprise Server
< Back to Support Search

SUSE Support Forums

Get your questions answered by experienced Sys Ops or interact with other SUSE community experts.

Join Our Community

Support Resources

Learn how to get the most from the technical support you receive with your SUSE Subscription, Premium Support, Academic Program, or Partner Program.


SUSE Customer Support Quick Reference Guide SUSE Technical Support Handbook Update Advisories
Support FAQ

Open an Incident

Open an incident with SUSE Technical Support, manage your subscriptions, download patches, or manage user access.

Go to Customer Center