Re: [POLL] Singleinstancestore
Jeremy, Sorry it took so long for me to respond. On Wed, 21 Jan 2004, Jeremy Rumpf wrote: [snip...] > From the TMS docs: Thanks! I asked out TSM folks here too, they came by with the manual. :) Slight difference, we use the backup / restore portion of TSM on our mail servers. It has the same paragraphs as the archive. :) [snip...] > So if you are using SSI, it seems that TSM will work the hard link magic for > you. And if it can't, it'll put down individual non-linked copies of the > files. This still could also lead to the situation where a selective restore > could end up utilizing more disk than the original files/links, but it looks > as if TSM tries harder than most to resolve things. Yes, it sounds like TSM will do the right thing. > Out of curiosity, how long does TSM take to run vs. the amount of mail data > you have? I've used TSM before, just not in this arena. We have a total of 12 spools on 4 different backend servers. The backups of the spools run concurrently, 3 per server, and TSM takes approx. 1 hour to backup the spools. Here is a sample report of 1 spool. Reporting imap.spool.07.log 01/22/04 23:02:38 01/22/04 23:02:38 Total number of objects inspected: 1,099,339 01/22/04 23:02:38 Total number of objects backed up: 25,000 01/22/04 23:02:38 Total number of objects updated: 0 01/22/04 23:02:38 Total number of objects rebound: 0 01/22/04 23:02:38 Total number of objects deleted: 0 01/22/04 23:02:38 Total number of objects expired: 15,234 01/22/04 23:02:38 Total number of objects failed: 8 01/22/04 23:02:38 Total number of bytes transferred: 1,014.87 MB 01/22/04 23:02:38 Data transfer time: 138.83 sec 01/22/04 23:02:38 Network data transfer rate:7,485.20 KB/sec 01/22/04 23:02:38 Aggregate data transfer rate:276.65 KB/sec 01/22/04 23:02:38 Objects compressed by:0% 01/22/04 23:02:38 Elapsed processing time: 01:02:36 01/22/04:23:02:38 Dump of /ssa/imap/spool/07 completed. - Bill
Re: [POLL] Singleinstancestore
Ken Murchison wrote: Does anyone out there actually disable singleinstancestore, and if so why? Rob and I are working on some code changes and as part of them are considering just having SIS always enabled. Is this going to create a problem for any installations? Never mind, I have already gone ahead and coded the appropriate stuff to continue to obey the singlesinstancestore option (it can still be disabled). -- Kenneth Murchison Oceana Matrix Ltd. Software Engineer 21 Princeton Place 716-662-8973 x26 Orchard Park, NY 14127 --PGP Public Key--http://www.oceana.com/~ken/ksm.pgp
Re: [POLL] Singleinstancestore
Bill Earle wrote: Ken, We do NOT use singleinstancestore. We have several partitions for spools. Is the feature intelligent enough to determine which spools are on the same partition and hardlink those and create individual files for spools on separate partitions? Yes it is, and has been. - we use qmail and the deliver program, which is called one recpient, one message at a time, so this may not even effect us either way. Correct, unless you get multiple recipients on one LMTP transaction, you won't see any benefit from SIS. We also would prefer to backup the files not a hardlink for restore purposes. I don't claim to know what the interaction with TSM and files vs. links are, but we are quite happy with files. TSM does an incremental forever backup, so only changes are backed up to tape. Does anyone know how the following scenario would be handled? I guess this would depend on how the software archives the hard links. -- Kenneth Murchison Oceana Matrix Ltd. Software Engineer 21 Princeton Place 716-662-8973 x26 Orchard Park, NY 14127 --PGP Public Key--http://www.oceana.com/~ken/ksm.pgp
Re: [POLL] Singleinstancestore
Ken, We do NOT use singleinstancestore. We have several partitions for spools. Is the feature intelligent enough to determine which spools are on the same partition and hardlink those and create individual files for spools on separate partitions? - we use qmail and the deliver program, which is called one recpient, one message at a time, so this may not even effect us either way. We also would prefer to backup the files not a hardlink for restore purposes. I don't claim to know what the interaction with TSM and files vs. links are, but we are quite happy with files. TSM does an incremental forever backup, so only changes are backed up to tape. Does anyone know how the following scenario would be handled? scenario: message 1 is sent to studentB and facultyB - both are on the same partition TSM backs up message 1: - (file) for studentA - (link) for facultyB no changes have taken place to the file. studentA, no longer attends the university and the backup of their files expires. The tape copy is now gone. facultyB, accidentaly removes the file and requests a restore - does TSM have the file from studentA or just the link from facultyB? Thanks, - Bill On Wed, 21 Jan 2004, Ken Murchison wrote: > Alexey Melnikov wrote: > > > Ken Murchison wrote: > > > >> Does anyone out there actually disable singleinstancestore, and if so > >> why? > >> > >> Rob and I are working on some code changes and as part of them are > >> considering just having SIS always enabled. Is this going to create a > >> problem for any installations? > > > > > > If single instance store is implemented by checking Message-Id, this > > doesn't work in the real world. Outlook (or Outlook Express) keeps the > > original Message-Id when resending a message... > > We're not talking about duplicate suppression. We're talking about when > a message is sent to multiple recipients, we only have one instance of a > message in the spool and hardlinking to it from other mailboxes. > > -- > Kenneth Murchison Oceana Matrix Ltd. > Software Engineer 21 Princeton Place > 716-662-8973 x26 Orchard Park, NY 14127 > --PGP Public Key--http://www.oceana.com/~ken/ksm.pgp >
Re: [POLL] Singleinstancestore
Alexey Melnikov wrote: Ken Murchison wrote: Does anyone out there actually disable singleinstancestore, and if so why? Rob and I are working on some code changes and as part of them are considering just having SIS always enabled. Is this going to create a problem for any installations? If single instance store is implemented by checking Message-Id, this doesn't work in the real world. Outlook (or Outlook Express) keeps the original Message-Id when resending a message... We're not talking about duplicate suppression. We're talking about when a message is sent to multiple recipients, we only have one instance of a message in the spool and hardlinking to it from other mailboxes. -- Kenneth Murchison Oceana Matrix Ltd. Software Engineer 21 Princeton Place 716-662-8973 x26 Orchard Park, NY 14127 --PGP Public Key--http://www.oceana.com/~ken/ksm.pgp
