Could be many things but maybe you've got an I/O bottleneck - you're trying to push too much stuff through a small pipe (for instance you're I/O controller can't handle the throughput). Or it's likely that if You've got a single disk and multiple users are reading/writing to/from It, the disk heads simply can't do two physical tasks at once and you Get high I/O wait times. I see the same symptoms on my own Computer if it's doing something I/O intensive like reading or writing A big file, and I try to do something else at the same time, this behaviour Is quite normal. That's why servers should have multiple disks configured In a RAID array so you can utilize multiple disk heads and minimize I/O Bottlenecks. Install the sysstat package and type "sar 1 100", what does that say? Example output, you can see the iowait time our server is low (we've got An external disk array): [root@server]# sar 1 100 Linux 2.6.18-92.1.10.el5 (server.domain) 01/30/2009 06:47:59 PM CPU %user %nice %system %iowait %steal %idle 06:48:00 PM all 6.25 0.00 2.00 0.00 0.00 91.75 06:48:01 PM all 2.00 0.00 2.25 0.25 0.00 95.50 06:48:02 PM all 5.50 0.00 5.25 0.00 0.00 89.25 06:48:03 PM all 1.25 0.00 1.75 0.25 0.00 96.75 Regards, Geofrey. -----Original Message----- From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Vishnu Vardhan Reddy Sent: Friday, 30 January 2009 6:36 p.m. To: General Red Hat Linux discussion list Subject: Linux server hangs Dear All, I just had a really bad experience with one of the IBM Server which has Red Hat RHEL 4 WS with update 6 OS on it. It has two SATA hard disks out of which one is of 80 GB( contains /boot, / & swap partitions) and on other disk 250 GB single partition ( /data). On this serve I am currently running samba, nfs, ftp services & some embedded tools, with 20 users who works entirely on this server through telnet, samba services, and compiles the source on this related to embedded tools. My problem is, if all the users are logged in through telnet, ftp and access data through samba and perform some I/O operations like copying, moving and deleting data, the server getting hanged for 30 seconds and further becomes slow until the application is closed or completed, this effects other users terminals. As per my observation if I copy some 500 MB file from partition to partition, from disk to disk, or when I start checkout from CVS the CPU utilization is showing less, but server freezes for some time. Even I cont open any file through VI, after the application is closed the server becomes fast, all the users can work with VI editor. Can anyone help me in this issue? Thanks Vishnu -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list ========================================================== For more information on the Television New Zealand Group, visit us online at tvnz.co.nz ========================================================== CAUTION: This e-mail and any attachment(s) contain information that is intended to be read only by the named recipient(s). This information is not to be used or stored by any other person and/or organisation. -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
