Hi all: I realize this is slightly off topic, but is an issue of concern with the use of ssd's. We are setting up a storage server under solaris using ZFS. We have a couple of ssd's 2 x 160GB Intel X25-M MLC SATA acting as the zil (write journal) and are trying to see if it is safe to use for a power fail situation. Our testing (10 runs) hasn't shown any data loss, but I am not sure our testing has been running long enough and is valid, so I hoped the people here who have tested an ssd for data loss may have some guidance. The testing method is to copy a bunch of files over NFS to the server with the zil. When the copy is running along, pull the power to the server. The NFS client will stop and if the client got a message that block X was written safely to the zil, it will continue writing with block x+1. After the server comes backup and and the copies resume/finish the files are checksummed. If block X went missing, the checksums will fail and we will have our proof. We are looking at how to max out the writes to the SSD on the theory that we need to fill the dram buffer on the SSD and get it saturated enough such that it can't flush data to permanent storage as fast as the data is coming in. (I.E. make it a writeback with a longer delay so it's more likely to drop data.) Does anybody have any comments or testing methodologies that don't involve using an actual postgres instance? Thanks for your help. -- -- rouilj John Rouillard System Administrator Renesys Corporation 603-244-9084 (cell) 603-643-9300 x 111 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
