On Thu, Jan 20, 2011 at 5:20 PM, Henrique Fernandes <sf.ri...@gmail.com> wrote:
>> > Not all, if this counts as large: >> > >> > Filesystem Size Used Avail Use% Mounted on >> > /dev/gpfsmail 9.9T 8.7T 1.2T 88% /maildirs >> > >> > Filesystem Inodes IUsed IFree IUse% Mounted on >> > /dev/gpfsmail 105279488 90286634 14992854 86% /maildirs >> > >> >> how do you backup that data? :) >> > Same question! > > I have about 1TB used and it takes 22 hrs to backup maildirs! Our maildirs are spread in subfolders under /maildirs/[a-z0-9], where mail addresses starting with a is stored under /maildirs/a/, b in /maildirs/b, etc.. and then we have distributed these top-level directories about evenly for backup by each host. So the 7 servers all run backups of different parts of the filesystem. The backups go to Tivoli Storage Manager, with it´s default incremental forever policy, so there´s not much data to back up. The problem is that it´s very slow to traverse all the directories and compare against what was already backed up. I believe we´re also using around 20-24 hours for the daily incremental backups... so we soon will have to start looking at alternative ways of doing it (or get rid of the non-dovecot accesses to maildirs, which are probably stealing quite a bit performance from the file scans). One alternative is the "mmbackup"-utility, which is supposed to use a much faster inode scan interface in GPFS: http://publib.boulder.ibm.com/infocenter/clresctr/vxrx/index.jsp?topic=%2Fcom.ibm.cluster.gpfs31.basicadm.doc%2Fbl1adm_mmback.html but last time we tested it it was a too fragile... -jf
