Temat: Klastrowy file system
A moze nie replikowac storage'em, tylko LVMem?
W GFS FAQ pisza:
"Can I use striping, hardware RAID, mirroring, etc., with GFS?
Yes you can. Since GFS can manage the contents of a block device (SCSI, logical volume, etc), there is still the underlying logical volume manager, LVM2, that takes care of things like spanning physical volumes, striping, hardware RAID, mirroring and such. For clusters, there is a special version of LVM2 called CLVM that is needed, but not much changes other than the locking protocol specified in /etc/lvm/lvm.conf.
Note that GFS won't work properly in a cluster with software RAID (the MD driver). At the time of this writing, software RAID is not cluster-aware. Since software RAID can only be running on one node in the cluster, the other nodes will not be able to see the data properly, or will likely destroy each other's data. However, if GFS is used as a stand-alone file system on a single-node, software RAID should be okay. "
czyli tak na prawde zeby to sprawdzic bylby potrzebny eksperyment z 4 wezlami (2 gfs clienty per site) i 2 sity + storage per site.
Na kazdym wezle musialby byc LVM(+CLVM) mirrorujacy na LUNy/PV w obydwu storage'ach, a na tak zestawionym VG dopiero GFS (?) Kazda macierz musialaby juz wystawiac zabezpieczonego LUNa jakims RAIDem wewnetrznym.
... Ale odczyt w przypadku odczytu ze zdalnego storage'u lezy (nie ma preferred read site).
Wole nie myslec o recovery i ilosci bledow w takiej infrastrukturze ;) ale testy same w sobie moga byc pouczajace ;)