RAID 1 vs RAID 5

I have been using RAID 5 on an HP LH3 using Sco-Unix for over a year and have had no problems. That is to say I have pulled perfectly working drives out of the bay and the technology recreated the drive on the hot swap. The VAR is telling me that my new HP LH4 using Win NT and RAID 5 on 4 18Gig drives (includes the hot swap) will not work properly with the Native Database. Is this true and does anyone out there have any experience? How about SQL with RAID 5? So far and that is 3 times on 3 different pieces of equipment with RAID 1, I have not been able to recover a database or drive in the mirrored pair, so I don’t trust mirroring period. Any comments, especially true life experiences would be most welcome. --jimmy

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We using stripping on NT server platform about 2 years. Any problems. I was founded some info about that NF writed database structure to FAT16 file system & using NTFS downgrade speed. We using NTFS, becouse if use FAT16 to few letters in alphabet :slight_smile:

I have also heard that RAID 5 is a problem on NT with tha Native database because Navision is supposed to Stripe if the database is larger than 2 GB. I would also like to implement RAID 5 if it will work, we have lost data in the past using a mirrored set. I am also considering a purchasing a High Availability product like Legato Co-Standby Server for NT. Legato’s product basically mirrors to another server and if the primary server fails, the standby server takes over as the primary server. (i.e. no down time, no data loss if it works as advertized.) Has anyone had any experence with any of the High Availability products? Will Giles Database Manager Quartzdyne, Inc.

I thought the only way to lose data with a mirrored set was to have failures on both drives or both controllers? Would Raid 5 protect you from having 2 disks fail? -jp

We had a hard drive fail completely and immeaditely a couple of years ago, in this case we lost no data with a mirrored set. Two weeks ago we had a hard drive start to malfunction in our Netware 3.2 server. The FAT table became corrupt and the corrupt data was copied to the mirrored disk corupting the data on that disk also. We tried various tools to rebuild the data on the good disk, but were unsuccessful. We ended up replacing the hard drives and reinstalling the OS and the backup software so we could restore yesterdays data from a tape. We also had to rebuild the bindry. In conclusion we feel that mirroring or duplexing is better protection than not, it does not always prevent the loss of data even if only one drive fails. Will Giles Database Manager Quartzdyne, Inc.

As far as I know running the CSIDE database on RAID 5 is fine… but when the database is expanded into two files on two partitions… a) you get no speed benefit if the files are all on the same RAID 5 array. b) Navision’s striping will apparently conflict with the RAID 5’s operation. I don’t expect that RAID 5 would conflict with the SQL server operation because Navision gains the benefits of such a platform like RAID 5 compatibility and clustering etc… Craig Bradney Technical Manager Criterion Technology Pty Ltd P:+61-2-9436-0436 F:+61-2-9436-1004 E:craigb@c-t.com.au

Allrightie then Let’s have a final word on this one. Its possible to run Raid5 AND Raid1. It seems that you’re all running the highest Raid possible. But as far as i remember Navision software tells everybody to run RAID1 because in this way the system runs as fast as possible. My own experience is that regardless of which Raid you’re running you are going to lose data if the hardware goes wrong. So my opinion is go for the speed and change to Raid1 Palle Arentoft, Team Manager Aston Naviteam A/S Denmark Email : par@astonitgroup.com