Is it bad to mix BCS and ZCS drives in the same volume? A person from a reputable Network Appliance supply company told me that this will probably most definitely lead to data corruption.
Please read below, I know its a lot of information but it should be useful for someone to give me a straight answer.
before we just had one FC9 shelf of seven 36GB ZCS disks on our F740 filer
slot 8: Fibre Channel Host Adapter 8 (Qlogic 2100 rev. 3, 32-bit, L-port, <UP>) 0: SEAGATE ST136403FC NA11 34.5GB 512B/sect 1: SEAGATE ST136403FC NA11 34.5GB 512B/sect 2: SEAGATE ST136403FC NA11 34.5GB 512B/sect 3: SEAGATE ST136403FC NA11 34.5GB 512B/sect 4: SEAGATE ST136403FC NA11 34.5GB 512B/sect 5: SEAGATE ST136403FC NA11 34.5GB 512B/sect 6: SEAGATE ST136403FC NA11 34.5GB 512B/sect
now we have another FC9 shelf of 36GB BCS disks but the sizes don't match
slot 8: Fibre Channel Host Adapter 8 (Qlogic 2100 rev. 3, 32-bit, L-port, <UP>) 0: SEAGATE ST136403FC NA11 34.5GB 512B/sect 1: SEAGATE ST136403FC NA11 34.5GB 512B/sect 2: SEAGATE ST136403FC NA11 34.5GB 512B/sect 3: SEAGATE ST136403FC NA11 34.5GB 512B/sect 4: SEAGATE ST136403FC NA11 34.5GB 512B/sect 5: SEAGATE ST136403FC NA11 34.5GB 512B/sect 6: SEAGATE ST136403FC NA11 34.5GB 512B/sect 8: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect 9: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect 10: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect 11: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect 12: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect 13: NETAPP X231_ST336704FC NA32 34.0GB 520B/sect
Before we added the second shelf I had it setup very nicely with a boot volume of 2 disks, data volume of 4 disks (w/one spare) and raid group size=7.
Volume boot (online, normal) (zoned checksums) Plex /boot/plex0 (online, normal, active) RAID group /boot/plex0/rg0 (normal)
RAID Disk Device HA SHELF BAY CHAN Used (MB/blks) Phys (MB/blks) --------- ------------ --------------- ---- -------------- -------------- parity 8.0 8 0 0 FC:A 34500/70656000 34732/71132960 data 8.1 8 0 1 FC:A 34500/70656000 34732/71132960
Volume saggy (online, normal) (zoned checksums) Plex /saggy/plex0 (online, normal, active) RAID group /saggy/plex0/rg0 (normal)
RAID Disk Device HA SHELF BAY CHAN Used (MB/blks) Phys (MB/blks) --------- ------------ --------------- ---- -------------- -------------- parity 8.2 8 0 2 FC:A 34500/70656000 34732/71132960 data 8.3 8 0 3 FC:A 34500/70656000 34732/71132960 data 8.4 8 0 4 FC:A 34500/70656000 34732/71132960 data 8.5 8 0 5 FC:A 34500/70656000 34732/71132960
Then a person with very little experience (my boss) added another shelf to the data volume but without first checking the types of disks he was adding, etc. He added NETAPP X231 (BCS) disks to this ZCS voume. These are block checksum disks of a different physical specs. Now it looks like this.
Volume saggy (online, normal) (zoned checksums) Plex /saggy/plex0 (online, normal, active) RAID group /saggy/plex0/rg0 (normal)
RAID Disk Device HA SHELF BAY CHAN Used (MB/blks) Phys (MB/blks) --------- ------------ --------------- ---- -------------- -------------- parity 8.2 8 0 2 FC:A 34500/70656000 34732/71132960 data 8.3 8 0 3 FC:A 34500/70656000 34732/71132960 data 8.4 8 0 4 FC:A 34500/70656000 34732/71132960 data 8.5 8 0 5 FC:A 34500/70656000 34732/71132960 data 8.6 8 0 6 FC:A 34500/70656000 34732/71132960 data 8.8 8 1 0 FC:A 34000/69632000 34190/70022840 data 8.9 8 1 1 FC:A 34000/69632000 34190/70022840
RAID group /saggy/plex0/rg1 (normal)
RAID Disk Device HA SHELF BAY CHAN Used (MB/blks) Phys (MB/blks) --------- ------------ --------------- ---- -------------- -------------- parity 8.10 8 1 2 FC:A 34000/69632000 34190/70022840 data 8.11 8 1 3 FC:A 34000/69632000 34190/70022840 data 8.12 8 1 4 FC:A 34000/69632000 34190/70022840 data 8.13 8 1 5 FC:A 34000/69632000 34190/70022840
Spare disks
RAID Disk Device HA SHELF BAY CHAN Used (MB/blks) Phys (MB/blks) --------- ------------ --------------- ---- -------------- -------------- Spare disks for block or zoned checksum volumes spare 8.14 8 1 6 FC:A 34000/69632000 34190/70022840
The spare is not even good enough if one of the ZCS drives fail!
Please let me how bad this is. Thanks!
Steve