Hi folks,
I'm searching experience on AdvFS robustness when 
harware is failing. We have had the following cases:
1) DECserver 3000/800 running OSF/1 vers. 2.0 connected 
with HSZ40 RAID controller, configured with 6 RAID5 
volumes each with 6 RZ28 disks. Alle RAID sets added to 
one large domain devided into 4 filesets. AdvFS 
log-files were located in a RAID5 volume on the same 
controller, the OSF system is a in a mirrored LSM-volume 
outside the RAID controller. Due to a hardware failure 
in the RAID controller, the system crashed and when 
rebooting we got a "panic" due to AdvFS inconsitency. We 
finally got the system up when mounting one of the file 
systems for read only. We upgraded to OSF ver. 3.0 
(recommended from egeneering) and were able to copy the 
corrupted fileset to a new, but when removing the 
corrupted set, the whole domain collapsed. Finally DEC 
support gave up and recommended to delete the whole 
domain an rely on the Networker Restore. We did not feel 
to well the next 40 hours waiting for 38GB of data to be 
restored.
DEC Engeneering now strongly recommended to move the 
AdvFS log files away from the RAID volumes and place 
them in mirrored LSM volumes. This is done today. 
2) DECserver 2100 running OSF/1 vers. 2.0 with a array 
controller 210 running RAID5, using 8 RZ28 disks all in 
one domain. The system disk and AdvFS log files are all 
located in the RAID volume. Just after having the 
previous case fixed, this RAID controller crashed too! 
One fileset was completely garbled du to an overwritten 
meta-file, another fileset had 4 files which could 
neither be read nor removed. Since this server was not 
in full productionm yet, only 1 GB had to be restored. 
We have not yet added extra disks to get the log-files 
out of the RAID-system.
It does not help much to secure the disks using RAID5 
when the whole file system logic get corrupted in stead?
Anyone else having such experiences?
Regards
Halvor Royset
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Company:   Norsk Hydro a.s       Contact: Halvor Royset
Phone:     +47 5599 6876         Fax:     +47 5599 6342
Address:   N-5020 Bergen, Norway Email: 
halvor.royset_at_nho.hydro.com
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Received on Mon Feb 06 1995 - 10:34:47 NZDT