Differences

This shows you the differences between two versions of the page.

--- computers:oak [2010/07/01 15:58] – chkuo
+++ computers:oak [2010/07/30 22:54] (current) – removed chkuo
@@ Line 1: / Line 1: @@
-====== Oak ======
-===== Services =====
-  * High-performance computation
-===== Hardware =====
-  * Model: NEC Express5800/T120a-M
-  * CPU: Intel Xeon E5520 (2.26 GHz, 4-core) * 2
-  * RAM: 4Gb DDR3 1066MHz * 4
-  * HDD: 3.5” SAS 15k RPM 450 Gb * 4, 3.5” SATA 2 Tb * 4
-==== RAID Setup ====
-  * ''/dev/sda''
-    * RAID 5 (2 Tb * 4)
-    * Mount at ''/''
-    * System partition
-  * ''/dev/sdb''
-    * RAID 0 (450 Gb * 4)
-    * Mount at ''/scratch''
-    * High-performance I/O
-==== RAID I/O Speed ====
-<code bash>
-$ sudo hdparm -tT /dev/sda
-/dev/sda:
- Timing cached reads:   15028 MB in  2.00 seconds = 7521.59 MB/sec
- Timing buffered disk reads:  960 MB in  3.00 seconds = 319.78 MB/sec
-$ sudo hdparm -tT /dev/sdb
-/dev/sdb:
- Timing cached reads:   14352 MB in  2.00 seconds = 7182.41 MB/sec
- Timing buffered disk reads:  1660 MB in  3.00 seconds = 553.13 MB/sec
-</code>
-===== Backup Plan =====
-==== Home ====
-No backup plan for ''/home'' in place yet.
-==== Scratch ====
-The ''/scratch'' directory is on a RAID 0 disk array for high-performance I/O. As a consequence, there is a higher risk of data loss for files in this directory. To protect against disk failure, a rotating backup is executed daily to backup the entire ''/scratch'' directory to ''/scratch_backup'' (on the same filesystem as ''/'', RAID 5 array). The shell script and the crontab involved are listed below:
-<code bash>
-$ cat /scratch_backup/daily_rotate.sh
-#!/bin/bash
-prefix=/scratch_backup/daily
-max=6
-# remove the oldest snapshot, if it exists
-if [ -e $prefix.$max ]; then
-	rm -rf $prefix.$max*
-fi;
-# shift the other snapshot(s) back by one, if they exist
-for (( i=$max;i>0;i=i-1 ))
-do
-    source_dir=$prefix.$(($i-1))
-    source_log=$prefix.$(($i-1)).log
-    target_dir=$prefix.$i
-    target_log=$prefix.$i.log
-    if [ -e $source_dir ]; then
-        mv $source_dir $target_dir
-    fi;
-    if [ -e $source_log ]; then
-        mv $source_log $target_log
-    fi;
-done
-# make the current snapshot
-rsync -av --delete \
-	--link-dest='$prefix.1' \
-	/scratch  $prefix.0 > $prefix.0.log 2>&1
-# update the timestamp
-touch $prefix.0
-</code>
-$ cat /etc/crontab
-# /etc/crontab: system-wide crontab
-# Unlike any other crontab you don't have to run the `crontab'
-# command to install the new version when you edit this file
-# and files in /etc/cron.d. These files also have username fields,
-# that none of the other crontabs do.
-SHELL=/bin/sh
-PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
-# m h dom mon dow user	command
-*	* * *	root    cd / && run-parts --report /etc/cron.hourly
-6	* * *	root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
-6	* * 7	root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
-6	1 * *	root	test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
-# daily backup for /scratch
-3    * * *   root    /scratch_backup/daily_rotate.sh
-<code bash>
-</code>
-===== Software =====