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>From: Tom Yoksas <address@hidden> >Organization: UCAR/Unidata >Keywords: 200405270011.i4R0BjtK010667 LDM Linux RAID JFS Hi Gerry, So, I looked at the /etc/raidtab and /etc/raidtab.old files on bigbird and compared them to the /etc/raidtab file on our dual Athlon MP 2800+ machine: /etc/raidtab from bigbird: [ldm@bigbird ~]$ cat /etc/raidtab # # 'persistent' RAID5 setup, with no spare disks: # modified (cleaned up) 2004 05 26, GCreager raiddev /dev/md0 raid-level 5 nr-raid-disks 7 nr-spare-disks 1 persistent-superblock 1 chunk-size 4 device /dev/hde1 raid-disk 0 device /dev/hdg1 raid-disk 1 device /dev/hdi1 raid-disk 2 device /dev/hdk1 raid-disk 3 device /dev/hdm1 raid-disk 4 device /dev/hdo1 raid-disk 5 device /dev/hdq1 raid-disk 6 device /dev/hds1 spare-disk 0 # raid-disk 7 # device /dev/hdl2 # spare-disk 0 # device /dev/hdt1 # spare-disk 1 /etc/raidtab from UPC dual Athlon MP 2800+ machine, created by Linux OS install [ldm@dhcp14 ~]$ cat /etc/raidtab raiddev /dev/md0 raid-level 0 nr-raid-disks 2 chunk-size 64 persistent-superblock 1 nr-spare-disks 0 device /dev/hde1 raid-disk 0 device /dev/hdg1 raid-disk 1 Two things: 1) your new raidtab file seems to have conflicting info in it: ... nr-spare-disks 1 ... spare-disk 0 2) the chunk-size specified in your raidtab file seems awfully small: chunk-size 4 Compare this with the size for our RAID: 64. Our size was chosen by the Linux installation itself. I am wondering if the performace would be better if the chunk-size was larger (like 128K) and the file system formated with larger blocks? Don't you think that a chunk-size of 4K is awfully small? Tom -- NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publically available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.