It is possible for the clients to mount the whole Filesystem read-only, which sets a flag on the MDS and OST for that client to have it return -EROFS for any Filesystem modifying operations.
However, it isn't possible to mount the OST itself read-only today. At one time there were patches in bugzilla that started to investigate this but they were never finished and landed. I suspect it wouldn't be too much worknfor someone to try mounting the OST with the "-o ro" mount option and then fixing the few places at mount time that are depending on being able to write to the filesystem. At the same time, I suspect that this isn't what you want to be doing when your system is already down, so it will have to be at a later time perhaps. Cheers, Andreas On 2010-07-09, at 12:00, Adeyemi Adesanya <[email protected]> wrote: > > > Hi. > > We are attempting to recover from a RAID controller issue in a storage > array that holds a couple of OSTs. We would like to tread carefully > and eventually remount the OSTs read-only so that clients can read > files striped to these OSTs but not write data. According to the 1.8 > manual, running 'lctl deactivate' on just the MDS will prevent new > objects from being allocated to the OST but will allow reads AND > writes to existing objects. Is there any way of preventing all kinds > of write activity to the OST (not just new object creation)? > > ------- > Yemi > _______________________________________________ > Lustre-discuss mailing list > [email protected] > http://lists.lustre.org/mailman/listinfo/lustre-discuss _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
