How would you define a 1G swap space with vdisk ? I have about 30 linux servers, each with about 1G swap on physical dasd. Can I use Vdisk for each of them ?
Can a 3G system handle 30G (or more) of vdisk ? What would be the system limit ? User limit ? I am a little confused about this. Can anyone point me to some simple documentation ? It would be nice to reclaim the 1G of swap dasd space for the user to use. Thanks -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Tom Duerbusch Sent: Monday, February 26, 2007 3:29 PM To: [email protected] Subject: Re: zVM 5.1 VDISK implementation Don't wait. If you are not storage constrained then vdisk for swap should almost never be a problem. My complaint was about vdisk in a storage constrained system, being abused by some memory hog process. How much vdisk? That's a tuning/monitoring process. I use 3 vdisks, 16 MB, 32 MB and 64 MB with different priorities. I think that is overkill for some of my machines, but hasn't been insufficient for any of them (yet). But my point has been, if you define it, expect that it may be totally used at some point (in my case, increasing the working set size by 112 MB, had a major impact on my production machines). I was in a 1 GB lpar, that was memory constrained, so a bump of 10% in working set size, was an issue. VS having a 16 MB vdisk, and a 3390 pack for second level swap. We have only been discussing a very minor set of circumstances, that, I agree, we shouldn't be in anyway. But, when in the trenches, you have to deal with, what you have. Think about, but don't worry about the 2 GB storage relief in 5.2. The storage problem was mostly in large, heavy I/O shops, as all I/O had to be done below the 2 GB line. With 5.2, that is no longer the case. Now, if your Linux images are going to be large, such as 4 GB Oracle, or DB2/UDB, and they become heavy I/O contenders, then you need to think/rethink/watch out, for that problem. Tom Duerbusch THD Consulting >>> [EMAIL PROTECTED] 2/26/2007 1:51 PM >>> All, looking for comments (situation below) on VDISK implementation for linux swap. After having read all the recent posts on use of VDISK (including layers) which we intend to do, mainly interested in timing of same? 1. "proceed vs. wait" with implementing VDISK swap space for RHEL guests running on z/VM Version 5 Release 1.0, Service Level 0601 (64-bit). We have had zVM5.2 on standby awaiting a DASD subsystem replacement (now zVM5.3 is available :-) ) & no space for 2nd level installation/testing. Current LPAR's (on redundant z9's) are not currently storage constrained - 1st at 40% of 12G & 2nd at 60% of 8G (each defined less 1G as XSTORE). Note: aware of many Conference Presentations indicating much better memory management (ie. above 2G line) with 5.2 or above; hence wanting advise/opinions on proceeding at 5.1 vs. waiting. We had hoped to have the DASD subsystem upgraded in Jan, but still waiting - and best guess would be late April early May before VM upgrade could be done, so wondering if I would have any negative affects of proceeding with VDISK swap areas at 5.1? Opinions please! Thanks -- [EMAIL PROTECTED] ITS/CS Network Systems Programmer State of North Carolina Office of Information Technology Services ----- E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties by an authorized state official. ----- ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
